The diagnosis of Ehlers-Danlos syndrome (EDS), classic type is established by family history and clinical examination. Diagnostic criteria were developed by a medical advisory group in a conference (sponsored by the Ehlers-Danlos Foundation [USA] and the Ehlers-Danlos Support Group [UK]) at Villefranche in 1997 [Beighton et al 1998; click for full text (pdf)]. ...
Diagnosis
Clinical DiagnosisThe diagnosis of Ehlers-Danlos syndrome (EDS), classic type is established by family history and clinical examination. Diagnostic criteria were developed by a medical advisory group in a conference (sponsored by the Ehlers-Danlos Foundation [USA] and the Ehlers-Danlos Support Group [UK]) at Villefranche in 1997 [Beighton et al 1998; click for full text (pdf)]. The combination of the first three major diagnostic criteria should have a high specificity for EDS, classic type. The presence of one or more minor criteria contributes to the diagnosis of EDS, classic type but is not sufficient to establish the diagnosis.Major diagnostic criteria for the classic type of EDSSkin hyperextensibility. Skin hyperextensibility (see Figure 1) should be tested at a neutral site (one not subjected to mechanical forces or scarring), such as the volar surface of the forearm. It is measured by pulling up the skin until resistance is felt. In young children, hyperextensibility of the skin is difficult to assess because of abundant subcutaneous fat.Widened atrophic scars. (see Figure 2) (a manifestation of tissue fragility)Joint hypermobility. Joint hypermobility (see Figure 3) depends on age, gender, and family as well as ethnic backgrounds. Joint hypermobility in classic EDS is general, affecting both large and small joints, and is usually noted when a child starts to walk. It should be assessed using the Beighton scale, the most widely accepted grading system for the objective semi-quantification of joint hypermobility (see Table 1).Positive family historyFigureFigure 1. Skin hyperextensibility FigureFigure 2. Widened atrophic scars FigureFigure 3. Passive flexion of thumbs to the forearm: manifestation of joint hypermobility Table 1. Beighton's Criteria for Joint HypermobilityView in own windowJoint/FindingNegativeUnilateralBilateralPassive dorsiflexion of the 5th finger >90°
012Passive flexion of thumbs to the forearm012Hyperextension of the elbows beyond 10°012Hyperextension of the knees beyond 10°012Forward flexion of the trunk with knees fully extended and palms resting on the floor01A total score of ≥5 defines hypermobility.Minor diagnostic criteria for the classic type of EDSSmooth, velvety skinMolluscoid pseudotumors: fleshy, heaped-up lesions associated with scars over pressure points such as the elbows and kneesSubcutaneous spheroids: small, cyst-like, hard shot-like nodules, freely moveable in the subcutis over the bony prominences of the legs and arms. They occur in approximately one third of affected individuals, are numerous, and feel like hard grains of rice. X-ray reveals an outer calcified layer with a translucent core. The spheroids represent subcutaneous fat globules that have lost their blood supply, becoming fibrosed and calcified.Complications of joint hypermobility (e.g., sprains, dislocations/subluxations, pes planus)Muscle hypotonia, delayed gross motor developmentEasy bruisingManifestations of tissue extensibility and fragility (e.g., hiatal hernia, anal prolapse in childhood, cervical insufficiency)Surgical complications (postoperative hernias)TestingElectron microscopy of a skin biopsy in EDS, classic type often suggests disturbed collagen fibrillogenesis. A "cauliflower" deformity of collagen fibrils is characteristic [Hausser & Anton-Lamprecht 1994]. However, these findings are not specific for EDS and thus not diagnostic. Furthermore, ultrastructural changes, usually most pronounced in the central parts of the reticular dermis, may be missed if the skin biopsy is not full thickness.Biochemical testing on cultured dermal fibroblasts. Collagen protein analysis is performed on cultured fibroblasts, derived from a skin biopsy in order to obtain a source of protein for electrophoretic analysis of collagen types I, III, and V. The collagens are labeled and analyzed on SDS-polyacrylamide gel electrophoresis. Abnormal proteins migrate differently on the gel when compared to control samples. Since type V collagen is synthesized by fibroblasts at low levels, alterations in electrophoretic mobility are poorly reproducible, making this an ineffective method for routine diagnostic evaluation. The test, however, helps to exclude other subtypes of EDS (e.g., the vascular, kyphoscoliotic, arthrochalasis, and dermatosparaxis types) in individuals in whom clinical differential diagnosis is difficult. Rarely, an abnormal electrophoretic pattern for type I collagen is detected due to the presence of an arginine-to-cysteine substitution in COL1A1 coding for the proα1(I) collagen chain of type I collagen [Nuytinck et al 2000, Malfait et al 2007]Molecular Genetic TestingGenes. In the majority of affected families (≥50%), the disease-causing mutation is identified in the genes encoding type V collagen, COL5A1 and COL5A2. However, since no prospective molecular studies of COL5A1 and COL5A2 have been performed in a clinically well-defined patient group, this number may underestimate the real proportion of individuals with classic EDS harboring a mutation in one of these genes. Evidence for locus heterogeneity. A COL1A1 mutation, p.Arg134Cys, was identified in two unrelated children with classic EDS [Nuytinck et al 2000]. The same substitution was subsequently identified in three unrelated persons with aneurysms and rupture of medium-sized arteries in young adulthood. These people also had thin and hyperextensible skin, easy bruising, and abnormal wound healing [Malfait et al 2007; Malfait and De Paepe, personal observation]. Mutations in COL1A1 are, however, not a major cause of classic EDS [Malfait et al 2005].Clinical testingSequence analysis. Approximately 50% of individuals with classic EDS have an identifiable mutation in COL5A1 or COL5A2. COL5A1 null alleles are detected in approximately 30%-40% of individuals with classic EDS [Malfait et al 2005].Deletion/duplication analysis. The usefulness of such testing has not been demonstrated, as no deletions or duplications involving COL5A1 or COL5A2 as causative of classic EDS have been reported.COL5A1 null allele test. The COL5A1 null allele test determines if the individual is heterozygous for one of several COL5A1 polymorphic exonic markers in gDNA and then establishes at the cDNA level whether both alleles are expressed. If only one of the two COL5A1 alleles is present in cDNA, it is assumed that the absent allele is null. Since this test examines both gDNA and cDNA, COL5A1 null allele testing requires cultured skin fibroblasts. It does not identify mutations within COL5A1 [Malfait et al 2005].Table 2. Summary of Molecular Genetic Testing Used in Ehlers-Danlos Syndrome, Classic TypeView in own windowGene SymbolProportion of EDS, Classic Type Attributed to Mutations in This GeneTest MethodMutations Detected Test AvailabilityCOL5A146% 1Sequence analysisSequence variants 2ClinicalDeletion / duplication analysis 3Exonic and whole-gene deletions / duplications 4 COL5A24% 1Sequence analysisSequence variants 2ClinicalDeletion / duplication analysis 3Exonic and whole-gene deletions / duplications 4 1. Malfait et al [2005], Malfait & De Paepe [2005]2. Examples of mutations detected by sequence analysis may include small intragenic deletions/insertions and missense, nonsense, and splice site mutations.3. Testing that identifies deletions/duplications not readily detectable by sequence analysis of the coding and flanking intronic regions of genomic DNA; included in the variety of methods that may be used are: quantitative PCR, long-range PCR, multiplex ligation-dependent probe amplification (MLPA), and chromosomal microarray (CMA) that includes this gene/chromosome segment.4. No deletions or duplications involving COL5A1 or COL5A2 have been reported to cause Ehlers-Danlos syndrome, classic type. (Note: By definition, deletion/duplication analysis identifies rearrangements that are not identifiable by sequence analysis of genomic DNA.)Interpretation of test results. For issues to consider in interpretation of sequence analysis results, click here.Testing StrategyTo confirm/establish the diagnosis in a proband. Molecular genetic testing for classic EDS is complicated by the large number of exons in the coding sequences (66 in COL5A1 and 52 in COL5A2) and the wide distribution of mutations. When a clinical diagnosis of classic EDS is suspected, we recommend the following evaluations: Perform sequence analysis by Sanger sequencing of COL5A1 and COL5A2 either on gDNA or cDNA. We recommend starting with sequence analysis of COL5A1 on gDNA, since most individuals with classic EDS harbor a unique mutation in this gene, leading to the introduction of a premature termination codon and nonsense-mediated decay of mRNA. When no COL5A1 mutation is found, sequence analysis of COL5A2 should be performed. Perform COL5A1 null allele test and biochemical testing. If sequence analysis of both COL5A1 and COL5A2 does not identify a causal variant in a person with the phenotype of classic EDS, the authors recommend obtaining a skin biopsy in order to perform a COL5A1 null allele test and biochemical testing. Prenatal diagnosis and preimplantation genetic diagnosis (PGD) for at-risk pregnancies require prior identification of the disease-causing mutation in the family. Genetically Related (Allelic) DisordersNo other phenotypes are associated with mutations in COL5A1 or COL5A2.
Ehlers-Danlos syndrome (EDS) is a connective tissue disorder characterized by skin hyperextensibility, abnormal wound healing, and joint hypermobility. Previously, two subtypes, EDS type I and EDS type II, differing only in phenotypic severity, were recognized; it is now apparent that they form a continuum of clinical findings....
Natural History
Ehlers-Danlos syndrome (EDS) is a connective tissue disorder characterized by skin hyperextensibility, abnormal wound healing, and joint hypermobility. Previously, two subtypes, EDS type I and EDS type II, differing only in phenotypic severity, were recognized; it is now apparent that they form a continuum of clinical findings.SkinCutaneous hyperextensibility is one of the cardinal features of EDS in general and of classic EDS in particular. Skin extends easily and snaps back after release (unlike lax, redundant skin, as in cutis laxa).The skin is smooth and velvety to the touch.The skin is fragile, as manifested by splitting of the dermis following relatively minor trauma, especially over pressure points (knees, elbows) and areas prone to trauma (shins, forehead, chin). Skin fragility may cause dehiscence of sutured incisions in skin or mucosa.Wound healing is delayed, and stretching of scars after apparently successful primary wound healing is characteristic. Scars become wide, with a "cigarette-paper"-like or papyraceous appearance.Other dermatologic features in classic EDS:Molluscoid pseudotumors (see Clinical Diagnosis)Subcutaneous spheroids (see Clinical Diagnosis)Piezogenic papules: small, painful, reversible herniations of underlying adipose tissue globules through the fascia into the dermis, such as on medial and lateral aspects of the feet upon standingElastosis perforans serpiginosa: a rare skin condition of unknown etiology characterized by skin-colored to erythematous keratotic papules, some enlarging outwards in serpiginous or arcuate configurations, leaving slightly atrophic centersAcrocyanosis: a painless disorder caused by constriction or narrowing of the small blood vessels in the skin (affecting mainly the hands) in which the affected areas turn blue and become cold and sweaty; localized swelling may also occurChilblains: cold injuries, characterized by a red swollen skin that is tender, hot to the touch, and may itch; can develop in less than two hours in skin exposed to coldTissue fragility. Manifestations of generalized tissue extensibility and fragility are observed in multiple organs:Cervical insufficiency during pregnancyInguinal and umbilical herniaHiatal and incisional herniaRecurrent rectal prolapse in early childhoodJointsComplications of joint hypermobility including dislocations of the shoulder, patella, digits, hip, radius, and clavicle may occur and usually resolve spontaneously or are easily managed by the affected individual. Some individuals with classic EDS may experience chronic joint and limb pain, despite normal skeletal radiographs.Other problems related to the joint hypermobility are joint instability, foot deformities such as congenital clubfoot or pes planus, temporomandibular joint dysfunction, joint effusions, and osteoarthritis [Hagberg et al 2004, De Coster et al 2005a, De Coster et al 2005b].Neurologic features. Primary muscular hypotonia may occur and may cause delayed motor development, problems with ambulation, and mild motor disturbance. Fatigue and muscle cramps are relatively frequent. Rarely, CSF leak has been reported to cause postural hypotension and headache in individuals with classic EDS [Schievink et al 2004].Easy bruising. Easy bruising is a common finding and manifests as spontaneous ecchymoses, frequently recurring in the same areas and causing a characteristic brownish discoloration of the skin, especially in exposed areas such as shins and knees. There is a tendency toward prolonged bleeding (e.g., following brushing of the teeth) in spite of a normal coagulation status.CardiovascularStructural cardiac malformations are uncommon in classic EDS.Mitral valve prolapse and, less frequently, tricuspid valve prolapse may occur. Stringent criteria should be used for the diagnosis of mitral valve prolapse.Aortic root dilatation may be more common than previously thought [Wenstrup et al 2002]. A recent retrospective study showed that three out of 50 (6%) individuals with classic EDS had aortic dilatation at their first echocardiogram, which was performed at a median age of 16 years. However, the dilatation tended to be of little clinical consequence and the mitral valve prolapse is rarely severe. Medical or surgical intervention is rarely necessary for either [Atzinger et al 2011].Spontaneous rupture of large arteries, along with intracranial aneurysms and arteriovenous fistulae, may occur in the rare individual with a severe form of classic EDS.Pregnancy in a woman with classic EDS bears risk for the newborn as well as for the mother. As a whole, these complications are more frequent than in the normal population; however, it is difficult to quantitate the incidence of each complication in affected individuals because no good studies exist:Premature rupture of the membranes and prematurity can occur when the mother is affected, and also when the fetus is affected, especially in the most severe forms. Because of hypotonia, breech presentation is more frequent if the baby is affected and may lead to dislocation of the hips or shoulder of the newborn.In affected women, tearing of the perineal skin by forceps and, after delivery, extension of episiotomy incisions and prolapse of the uterus and/or bladder may occur.
The number of individuals described with mutations in COL5A1 or COL5A2 is relatively small. Although there can be some variability in severity of the phenotype, no genotype/phenotype correlations have emerged to date. In particular, no difference in severity is noted in individuals with a COL5A1 null mutation as compared to individuals with a structural mutation or those in whom no mutation can be detected. ...
Genotype-Phenotype Correlations
The number of individuals described with mutations in COL5A1 or COL5A2 is relatively small. Although there can be some variability in severity of the phenotype, no genotype/phenotype correlations have emerged to date. In particular, no difference in severity is noted in individuals with a COL5A1 null mutation as compared to individuals with a structural mutation or those in whom no mutation can be detected. Mutations in COL5A1 that encode the amino-terminal region of the proα1(V) collagen chain appear to be associated with a phenotype that can differ slightly from the classic EDS phenotype. A p.Gly530Ser substitution in the amino-terminal propeptide of the α1(V) chain may be disease-modifying when present in the heterozygous state and disease-causing in the homozygous state [Giunta & Steinmann 2000, Giunta et al 2002]. A particular splice site mutation with a complex outcome within the amino-terminal region of the proα1(V) collagen chain was recently shown to result in a classic EDS-like phenotype with only minor cutaneous involvement (absence of the characteristic atrophic scarring) but with severe kyphoscoliosis and retinal detachment [Symoens et al 2011].
Other forms of Ehlers-Danlos syndrome (EDS) should be considered in individuals with easy bruising, joint hypermobility, and/or chronic joint dislocation. The disorders in which clinical findings overlap with the classic type of EDS include the following:...
Differential Diagnosis
Other forms of Ehlers-Danlos syndrome (EDS) should be considered in individuals with easy bruising, joint hypermobility, and/or chronic joint dislocation. The disorders in which clinical findings overlap with the classic type of EDS include the following:Ehlers-Danlos syndrome, hypermobility type (EDS type III). In this form, joint hypermobility is the primary manifestation. The skin is often soft or velvety and may be mildly hyperextensible. Subluxations and dislocations are common; they may occur spontaneously or with minimal trauma and can be acutely painful. Degenerative joint disease is common. Chronic pain, distinct from that associated with acute dislocations or advanced osteoarthritis, is a serious complication of the condition and can be both physically and psychologically disabling. Easy bruising is common, but atrophic scarring is more characteristic of the classic type of EDS. Joint hypermobility is the primary clinical manifestation. Skin abnormalities, such as variable skin hyperextensibility and smooth velvety skin, are found; but the presence of atrophic scars in individuals with joint hypermobility suggests the diagnosis of classic EDS.The diagnosis of EDS, hypermobility type is based entirely on clinical evaluation and family history. In most individuals with EDS, hypermobility type, the gene in which mutation is causative is unknown and unmapped [Malfait et al 2006a]. Haploinsufficiency of TNXB (the gene encoding tenascin X) and heterozygosity for missense mutations in TNXB have been associated with EDS, hypermobility type in a small subset of affected individuals (see Tenascin X deficiency) [Zweers et al 2003, Zweers et al 2005]. A single occurrence of a COL3A1 mutation in a family thought to have EDS, hypermobility type has been reported. Inheritance is autosomal dominant.Tenascin X deficiency. Homozygous mutations have been identified in TNXB in individuals with an autosomal recessive EDS phenotype characterized by mild joint hypermobility, skin hyperextensibility, and easy bruising but without atrophic scarring [Schalkwijk et al 2001, Lindor & Bristow 2005]. Heterozygotes for the same mutation, especially females, appear to have an EDS hypermobility phenotype.Familial joint hypermobility syndrome, and other syndromes in which hypermobility is found, share hypermobility of the joints with classic EDS; but the absence of skin hyperextensibility and atrophic scarring excludes the diagnosis of classic EDS.Ehlers-Danlos syndrome, vascular type (EDS type IV) is characterized by thin, translucent skin; easy bruising; characteristic facial appearance; and arterial, intestinal, and/or uterine fragility. Affected individuals are at risk for arterial rupture, aneurysm, and/or dissection; gastrointestinal perforation or rupture; and uterine rupture during pregnancy. One fourth of individuals with EDS, vascular type experience a significant medical problem by age 20 years and more than 80% by age 40 years. The median age of death is 48 years.The diagnosis of EDS, vascular type is based on clinical findings and confirmed by biochemical and/or molecular genetic testing. Biochemical studies in affected individuals demonstrate abnormal electrophoretic mobility and abnormal efficiency of secretion of type III procollagen by cultured dermal fibroblasts. Molecular genetic testing is used to identify mutations in COL3A1. Inheritance is autosomal dominant.Ehlers-Danlos syndrome, progeroid form is a rare autosomal recessive disorder characterized by progeroid appearance with wrinkled facies, curly and fine hair, scanty eyebrows and eyelashes, and periodontitis, in addition to typical signs of EDS. It is caused by homozygous mutations in B4GALT7, the gene encoding beta-1,4-galactosyltransferase 7.Ehlers-Danlos syndrome, kyphoscoliotic form (previously known as EDS type VI) is a generalized connective tissue disorder characterized by kyphoscoliosis, joint laxity, muscle hypotonia, and, in some individuals, fragility of the ocular globe. Intelligence is normal; life span may be normal, but affected individuals are at risk for rupture of medium-sized arteries and respiratory compromise if kyphoscoliosis is severe.EDS, kyphoscoliotic form is caused by mutation of PLOD1, resulting in deficient activity of the enzyme procollagen-lysine, 2-oxoglutarate 5-dioxygenase 1 (PLOD1: lysyl hydroxylase 1). The diagnosis of EDS, kyphoscoliotic form relies on the demonstration of an increased ratio of deoxypyridinoline to pyridinoline crosslinks in urine measured by HPLC, a highly sensitive and specific test. Assay of lysyl hydroxylase enzyme activity in skin fibroblasts and molecular genetic testing of PLOD1 are possible. Inheritance is autosomal recessive.Ehlers-Danlos syndrome, arthrochalasia type (previously called type VIIA & B) is distinguished by congenital bilateral hip dislocation and severe joint hypermobility. Tissue fragility (including atrophic scars) and skin hyperextensibility are usually present; severity ranges from mild to severe. It is caused by mutations in COL1A1 or COL1A2 leading to the deletion of exon 6 of the mRNA coding for the α1 chain (EDS VIIA) or the α2 chain (EDS VIIB) of type I collagen, respectively. Inheritance is autosomal dominant.Ehlers-Danlos syndrome, dermatosparaxis type (previously called EDS type VIIC) is characterized by extreme skin fragility, laxity, and a sagging, redundant appearance. Other distinct features are delayed closure of the fontanels, characteristic facies, edema of the eyelids, blue sclerae, umbilical hernia, short fingers, and short stature. The disorder is caused by deficient activity of procollagen-N-proteinase, the enzyme that excises the N-terminal propeptide in procollagen types I, II, and III [Malfait et al 2005]. Inheritance is autosomal recessive.Ehlers-Danlos syndrome, cardiac valvular form is characterized by joint hypermobility, skin hyperextensibility, and sometimes atrophic scarring, as well as cardiac valvular defects. Total absence of the proα2(I) chains of type I collagen as a result of homozygous or compound heterozygous mutations in COL1A2 is causative [Schwarze et al 2004, Malfait et al 2006b]. Inheritance is autosomal recessive.Classic-like EDS with propensity for arterial rupture. One arginine-to-cysteine (Arg-to-Cys) substitution in proα1(I) chain of type I collagen (p.Arg134Cys) has been identified in a series of individuals with a condition reminiscent of classic EDS that manifests as skin hyperextensibility, easy bruising, atrophic scarring, and joint hypermobility as well as a propensity for arterial rupture in adulthood [Nuytinck et al 2000, Malfait et al 2007]. Two other proα1(I) R-to-C substitutions (p.Arg396Cys and p.Arg915Cys) were also associated with rupture of medium-sized arteries, but affected individuals did not have EDS-like skin features [Malfait et al 2007]. Furthermore, a pro1(I)-p.Arg888Cys substitution was reported in a family presenting an EDS/osteogenesis imperfecta overlap phenotype [Cabral et al 2007], and a proα1(I)-p.Arg836Cys substitution was shown to be associated with autosomal dominant Caffey disease [Gensure et al 2005].Ehlers-Danlos syndrome and periventricular nodular heterotopia. Mutations in FLNA have been identified in a limited number of individuals with periventricular nodular heterotopia (a neuronal migration disorder characterized by seizures and conglomerates of neural cells around the lateral ventricles of the brain) and features of EDS [Gómez-Garre et al 2006]. See X-Linked Periventricular Heterotopia.Ehlers-Danlos syndrome spondylocheirodyplastic form is characterized by hyperextensible thin skin, easy bruising, hypermobility of the small joints with a tendency to contractures, protuberant eyes with bluish sclerae, hands with finely wrinkled palms, atrophy of the thenar muscles, and tapering fingers. Skeletal surveys show platyspondyly with moderate short stature, osteopenia, and widened metaphyses. Mutations in SLC39A13, encoding the membrane-bound zinc transporter SLC39A13, are causative [Giunta et al 2008]. Inheritance is autosomal recessive.The RIN2-syndrome (also known as MACS syndrome) is characterized by severe progressive scoliosis, progressive facial coarsening, gingival hypertrophy, sparse hair, and skin and joint hyperlaxity. It is caused by mutations in RIN2, the gene encoding the Ras and Rab interactor 2 that acts as a guanine nucleotide exchange factor (GEF) for the small GTPase Rab5, which is involved in early endocytosis [Basel-Vanagaite et al 2009, Syx et al 2010]. Inheritance is autosomal recessive.Ehlers-Danlos syndrome musculocontractural type is characterized by craniofacial dysmorphism, hyperextensible thin skin, atrophic scarring, easy bruising, small joint hypermobility, hands with finely wrinkled palms and tapered fingers, congenital contractures of distal joints, scoliosis, progressive muscle hypotonia, and variable gastrointestinal and genitourinary involvement. The condition is caused by mutations in CHST14, encoding dermatan 4 sulfotransferase-1, which is involved in the biosynthesis of dermatan sulfate. Inheritance is autosomal recessive [Malfait et al 2010, Miyake et al 2010].Classic EDS shows limited overlap with other connective tissue disorders, including variants of the following; these disorders are differentiated by other distinctive clinical features:Marfan syndrome, caused by mutation of FBN1, has a broad continuum of clinical manifestations involving the ocular, skeletal, and cardiovascular systems. Lens dislocation, seen in approximately 60%, is a hallmark feature. Myopia, retinal detachment, glaucoma, and early cataract formation are seen. Bone overgrowth leads to long extremities, pectus deformity (excavatum or carinatum), and joint laxity; scoliosis is common. Cardiovascular manifestations include dilatation of the aorta, a predisposition for aortic tear and rupture, mitral valve prolapse with or without regurgitation, tricuspid valve prolapse, and enlargement of the proximal pulmonary artery. Marfan syndrome is a clinical diagnosis based on family history and the observation of characteristic findings in multiple organ systems. Diagnostic criteria have been established. Inheritance is autosomal dominant.Occipital horn syndrome (OHS) (see ATP7A-Related Copper Transport Disorders) is characterized by "occipital horns," distinctive wedge-shaped calcifications at the sites of attachment of the trapezius muscle and the sternocleidomastoid muscle to the occipital bone. Occipital horns may be clinically palpable or observed on skull radiographs. Individuals with OHS also have lax skin and joints, bladder diverticula, inguinal hernias, and vascular tortuosity. There is no particular ease of bruising or fragility of the skin. Serum copper concentration and serum ceruloplasmin concentration are low. Mutation of ATP7A is causative. Inheritance is X-linked.Hyperextensible skin should also be distinguished from that observed in the cutis laxa syndromes and in De Barsy syndrome, in which the redundant skin hangs in loose folds and only returns very slowly to its former position. In these syndromes, the skin is not fragile and wound healing is normal. The cutis laxa syndromes result from the loss or fragmentation of the elastic fiber network. They are variably associated with pulmonary, cardiac, arterial, and gastrointestinal abnormalities. Cutis laxa syndromes comprise autosomal dominant, autosomal recessive, and X-linked forms. The autosomal dominant form is caused by mutations in ELN, encoding elastin. Autosomal recessive forms of cutis laxa are associated with mutations in the genes encoding fibulin 4 and fibulin 5 (FBLN4 and FBLN5), and more recently also with mutations in ATP6V0A2 and PYCR1. Note to clinicians: For a patient-specific ‘simultaneous consult’ related to this disorder, go to , an interactive diagnostic decision support software tool that provides differential diagnoses based on patient findings (registration or institutional access required).
For a detailed review of complications and management, see Wenstrup & Hoechstetter [2004]....
Management
For a detailed review of complications and management, see Wenstrup & Hoechstetter [2004].Evaluations Following Initial DiagnosisTo establish the extent of disease in an individual diagnosed with Ehlers-Danlos syndrome (EDS), classic type, the following evaluations are recommended:Clinical examination of the skin with assessment of skin hyperextensibility, atrophic scars and bruises, and other manifestations of classic EDSEvaluation of joint mobility with use of the Beighton scoreEvaluation for hypotonia and motor development in infants and childrenA baseline echocardiogram with aortic diameter measurement for individuals under age ten yearsEvaluation of clotting factors if severe easy bruising is presentTreatment of ManifestationsIn children with hypotonia and delayed motor development, a physiotherapeutic program is important.Non-weight-bearing muscular exercise, such as swimming, is useful to promote muscular development and coordination.Individuals with muscle hypotonia and joint instability with chronic pain may have to adjust lifestyle and professional choices accordingly. Emotional support and behavioral and psychological therapy may help in developing acceptance and coping skills.Dermal wounds should be closed without tension, preferably in two layers. Deep stitches should be applied generously. Cutaneous stitches should be left in place twice as long as usual and additional fixation of adjacent skin with adhesive tape can help prevent stretching of the scar.For recommendations on treatment of joint laxity and dislocations, see EDS, Hypermobility Type. (Note: Surgical stabilization of joints may lead to disappointing, or only temporary, improvement.)Anti-inflammatory drugs may help with joint pain.Long-term chronic pain may result in the need for mental health services.Cardiovascular problems should be treated in a standard manner.Prevention of Primary ManifestationsVery young children with pronounced skin fragility can wear protective pads or bandages over the forehead, knees, and shins in order to avoid skin tears. Older children who are active can wear soccer pads or ski stockings with shin padding during activities.For recommendations on prevention of primary manifestations of joint laxity and dislocations, see EDS, Hypermobility Type: Management, Prevention of Primary Manifestations. Ascorbic acid (vitamin C) may reduce easy bruising but has no effect on the primary findings of skin hyperextensibility, atrophic scarring, and joint hypermobility. In general, a dose of two grams per day is recommended for adults, with proportionally reduced doses for children; however, there is no limitation. Prevention of Secondary ComplicationsFor recommendations on prevention of secondary manifestations of joint laxity and dislocations, see EDS, Hypermobility Type: Management, Prevention of Secondary Complications.SurveillanceIf no abnormalities are found on echocardiogram in an adult, a follow-up echocardiogram is not necessary. (Because longitudinal data on progression of aortic dilation are not available, specific recommendations for follow-up in individuals with a normal aortic diameter are not available.)Yearly echocardiogram is warranted if an abnormality such as aortic dilatation or mitral valve prolapse is present.Agents/Circumstances to AvoidThe following should be avoided:Sports with heavy joint strain (contact sports, fighting sports, football, running)Acetylsalicylate (aspirin)Evaluation of Relatives at RiskSee Genetic Counseling for issues related to testing of at-risk relatives for genetic counseling purposesPregnancy Management Because of the increased risk of skin lacerations, postpartum hemorrhages, and prolapse of the uterus and/or bladder, monitoring of women throughout pregnancy and in the postpartum period is recommended.Ascorbic acid (vitamin C) may reduce easy bruising (see Prevention of Primary Manifestations). In general, a dose of two grams per day is recommended for adults; however, no strict guidelines exist regarding recommended dose during the third trimester of pregnancy.Monitoring of pregnant women for preterm labor is warranted during the third trimester when the risk of premature rupture of the membranes is increased.Therapies Under InvestigationSearch ClinicalTrials.gov for access to information on clinical studies for a wide range of diseases and conditions. Note: There may not be clinical trials for this disorder.
Information in the Molecular Genetics and OMIM tables may differ from that elsewhere in the GeneReview: tables may contain more recent information. —ED....
Molecular Genetics
Information in the Molecular Genetics and OMIM tables may differ from that elsewhere in the GeneReview: tables may contain more recent information. —ED.Table A. Ehlers-Danlos Syndrome, Classic Type: Genes and DatabasesView in own windowGene SymbolChromosomal LocusProtein NameLocus SpecificHGMDCOL5A19q34.3
Collagen alpha-1(V) chainEhlers-Danlos Syndrome Variant DatabaseCOL5A1COL5A22q32.2Collagen alpha-2(V) chainEhlers-Danlos Syndrome Variant DatabaseCOL5A2Data are compiled from the following standard references: gene symbol from HGNC; chromosomal locus, locus name, critical region, complementation group from OMIM; protein name from UniProt. For a description of databases (Locus Specific, HGMD) to which links are provided, click here.Table B. OMIM Entries for Ehlers-Danlos Syndrome, Classic Type (View All in OMIM) View in own window 120190COLLAGEN, TYPE V, ALPHA-2; COL5A2 120215COLLAGEN, TYPE V, ALPHA-1; COL5A1 130000EHLERS-DANLOS SYNDROME, TYPE I 130010EHLERS-DANLOS SYNDROME, TYPE IICOL5A1Normal allelic variants. The COL5A1 cDNA comprises 66 exons distributed over more than 150 kb of genomic DNA.Pathologic allelic variants. Several types of mutations have been identified in both COL5A1 and COL5A2:The most common types of molecular defect lead to haploinsufficiency for COL5A1 mRNA. In approximately 40% of individuals with classic EDS, nonsense or frameshift mutations are responsible for a non-functional COL5A1 allele [Schwarze et al 2000, Wenstrup et al 2000, Schwarze et al 2001, Malfait et al 2005]. Nonsense, frameshift, or splice-site mutations that introduce a premature termination codon are usually responsible for this non-functional COL5A1 allele. A variety of mechanisms lead to nonsense-mediated decay of the mutation-bearing mRNA or to failure of the chains to associate. The predicted consequence is synthesis of approximately half the amount of normal type V collagen.Structural mutations in COL5A1, which exert a dominant-negative effect, have been demonstrated in approximately ten to 15 individuals with classic EDS. In a small proportion of individuals, a mutation affects the structural integrity of type V collagen, resulting in the production of a functionally defective type V collagen protein (dominant-negative mutation). These structural mutations are most commonly splice-site mutations that result in exon skipping [Burrows et al 1998, Malfait et al 2005] and a few point mutations that result in the substitution for glycine in the triple-helical region of the collagen molecule [Giunta & Steinmann 2000, Malfait et al 2005]. A unique point mutation in COL5A1 that changes a highly conserved cysteine residue to a serine in the C-terminal propeptide of the α1(V) collagen chain has also been identified (p.Cys1639Ser) (NM_000093.3:c.4916G>C). In contrast to other disorders characterized by mutations in the fibrillar collagen genes, remarkably few mutations resulting from the substitution of a glycine by a bulkier amino acid have been found.A p.Gly530Ser (NM_000093.3: c.1588G>A) substitution in the amino-terminal propeptide of the α1(V) chain may be disease-modifying when present in the heterozygous state and disease-causing in the homozygous state [Giunta & Steinmann 2000, Giunta et al 2002]. Normal gene product. Collagen α1 (V) chain (type V collagen chains). Type V collagen is a quantitatively minor fibrillar collagen that is widely distributed in a variety of tissues. It is present mainly as [α1(V)]2 α2(V) heterotrimers in skin, bone, and tendon. It forms heterotypic fibrils with type I collagen and regulates the diameter of those fibrils, presumably through its very large amino-terminal propeptide. Recent data indicate that type V collagen controls collagen fibril assembly in several tissues [Wenstrup et al 2004].Abnormal gene product. Missense mutations in the triple helical domain of the α1(V) or α2(V) chains are likely to have dominant-negative activity; i.e., the mutant forms can interfere with the utilization of the normal protein derived from the normal allele. Diminished amounts, caused by premature termination of codons in COL5A1 or mRNA product, may alter normal collagen fibrillogenesis.COL5A2Normal allelic variants. The COL5A2 cDNA comprises 51 exons distributed over 67 kb.Pathologic allelic variants. Structural mutations in COL5A2 have been demonstrated in few individuals with classic EDS. These structural mutations are most commonly splice-site mutations that result in exon skipping [Michalickova et al 1998, Malfait et al 2005] and one point mutation that results in a substitution for glycine in the triple helical region of the collagen molecule [Richards et al 1998].Normal gene product. Collagen α2(V) chains (type V collagen chains). Type V collagen is a quantitatively minor fibrillar collagen that is widely distributed in a variety of tissues. It is present mainly as [α1(V)]2, α2(V) heterotrimers in skin, bone, and tendon. It forms heterotypic fibrils with type I collagen and regulates the diameter of those fibrils, presumably through its very large amino-terminal propeptide.Abnormal gene product. Missense mutations in the triple helical domain of the α1(V) or α2(V) chains are likely to have dominant-negative activity; that is, the mutant forms can interfere with the utilization of the normal protein derived from the normal allele.