Down syndrome

General Information (adopted from Orphanet):

Synonyms, Signs: DOWN SYNDROME CRITICAL REGION, INCLUDED
TRANSIENT MYELOPROLIFERATIVE DISORDER OF DOWN SYNDROME, INCLUDED
DCR, INCLUDED
LEUKEMIA, MEGAKARYOBLASTIC, OF DOWN SYNDROME, INCLUDED
DOWN SYNDROME CHROMOSOME REGION, INCLUDED
DSCR, INCLUDED
Trisomy 21
Number of Symptoms 74
OrphanetNr: 870
OMIM Id: 190685
ICD-10: Q90
UMLs: C0013080
MeSH: D004314
MedDRA: 10044688
Snomed: 41040004

Prevalence, inheritance and age of onset:

Prevalence: No data available.
Inheritance: sporadic
Sporadic
[Omim]
Age of onset: Neonatal/infancy
[Omim]

Disease classification (adopted from Orphanet):

Parent Diseases: No data available.

Symptom Information: Sort by abundance 

1
(HPO:0008678) Renal hypoplasia/aplasia Occasional [Orphanet] 127 / 7739
2
(HPO:0000789) Infertility Frequent [Orphanet] 74 / 7739
3
(HPO:0005989) Redundant neck skin Very frequent [Orphanet] 40 / 7739
4
(HPO:0000160) Narrow mouth Frequent [Orphanet] 188 / 7739
5
(HPO:0012471) Thick vermilion border Frequent [Orphanet] 115 / 7739
6
(HPO:0002714) Downturned corners of mouth Frequent [Orphanet] 98 / 7739
7
(HPO:0000474) Thickened nuchal skin fold 10 / 7739
8
(HPO:0012368) Flat face Very frequent [Orphanet] 106 / 7739
9
(HPO:0000272) Malar flattening 277 / 7739
10
(HPO:0000457) Depressed nasal ridge Frequent [Orphanet] 85 / 7739
11
(HPO:0000286) Epicanthus Very frequent [Orphanet] 371 / 7739
12
(HPO:0000582) Upslanted palpebral fissure Very frequent [Orphanet] 185 / 7739
13
(HPO:0005280) Depressed nasal bridge Very frequent [Orphanet] 381 / 7739
14
(HPO:0000691) Microdontia Frequent [Orphanet] 104 / 7739
15
(HPO:0003196) Short nose Frequent [Orphanet] 264 / 7739
16
(HPO:0002705) High, narrow palate Frequent [Orphanet] 308 / 7739
17
(HPO:0000164) Abnormality of the teeth Frequent [Orphanet] 291 / 7739
18
(HPO:0000470) Short neck Very frequent [Orphanet] 345 / 7739
19
(HPO:0000158) Macroglossia Frequent [Orphanet] 119 / 7739
20
(HPO:0010808) Protruding tongue 28 / 7739
21
(HPO:0000248) Brachycephaly Very frequent [Orphanet] 222 / 7739
22
(HPO:0000239) Large fontanelles Frequent [Orphanet] 135 / 7739
23
(HPO:0000194) Open mouth Frequent [Orphanet] 70 / 7739
24
(HPO:0001088) Brushfield spots 8 / 7739
25
(HPO:0000518) Cataract Occasional [Orphanet] 454 / 7739
26
(HPO:0000545) Myopia Occasional [Orphanet] 286 / 7739
27
(HPO:0000486) Strabismus Occasional [Orphanet] 576 / 7739
28
(HPO:0008551) Microtia 98 / 7739
29
(HPO:0100830) Round ear Very frequent [Orphanet] 7 / 7739
30
(HPO:0000396) Overfolded helix 21 / 7739
31
(HPO:0000405) Conductive hearing impairment Occasional [Orphanet] 164 / 7739
32
(HPO:0001249) Intellectual disability 1089 / 7739
33
(HPO:0002511) Alzheimer disease 10 / 7739
34
(HPO:0002251) Aganglionic megacolon 78 / 7739
35
(HPO:0001288) Gait disturbance Occasional [Orphanet] 318 / 7739
36
(HPO:0007021) Pain insensitivity Occasional [Orphanet] 35 / 7739
37
(HPO:0100543) Cognitive impairment Frequent [Orphanet] 230 / 7739
38
(HPO:0005978) Type II diabetes mellitus Occasional [Orphanet] 68 / 7739
39
(HPO:0000821) Hypothyroidism Occasional [Orphanet] 141 / 7739
40
(HPO:0004209) Clinodactyly of the 5th finger Frequent [Orphanet] 288 / 7739
41
(HPO:0002866) Hypoplastic iliac wing 34 / 7739
42
(HPO:0004220) Short middle phalanx of the 5th finger 17 / 7739
43
(HPO:0003467) Atlantoaxial instability 6 / 7739
44
(HPO:0001388) Joint laxity 117 / 7739
45
(HPO:0001169) Broad palm 43 / 7739
46
(HPO:0003182) Shallow acetabular fossae 10 / 7739
47
(HPO:0000954) Single transverse palmar crease Frequent [Orphanet] 162 / 7739
48
(HPO:0001852) Sandal gap Frequent [Orphanet] 63 / 7739
49
(HPO:0001382) Joint hypermobility Very frequent [Orphanet] 231 / 7739
50
(HPO:0004279) Short palm Very frequent [Orphanet] 323 / 7739
51
(HPO:0001537) Umbilical hernia Frequent [Orphanet] 206 / 7739
52
(HPO:0002023) Anal atresia Occasional [Orphanet] 135 / 7739
53
(HPO:0100867) Duodenal stenosis 29 / 7739
54
(HPO:0002250) Abnormality of the large intestine Occasional [Orphanet] 32 / 7739
55
(HPO:0001513) Obesity Frequent [Orphanet] 172 / 7739
56
(HPO:0004322) Short stature 1232 / 7739
57
(HPO:0001006) Hypotrichosis Occasional [Orphanet] 219 / 7739
58
(HPO:0007495) Prematurely aged appearance Frequent [Orphanet] 44 / 7739
59
(HPO:0001674) Complete atrioventricular canal defect 11 / 7739
60
(HPO:0030680) Abnormality of cardiovascular system morphology Frequent [Orphanet] 355 / 7739
61
(HPO:0001909) Leukemia 46 / 7739
62
(HPO:0006733) Acute megakaryocytic leukemia 1 / 7739
63
(HPO:0005547) Myeloproliferative disorder 7 / 7739
64
(HPO:0002488) Acute leukemia Occasional [Orphanet] 29 / 7739
65
(HPO:0010978) Abnormality of immune system physiology Frequent [Orphanet] 148 / 7739
66
(HPO:0100763) Abnormality of the lymphatic system Frequent [Orphanet] 18 / 7739
67
(HPO:0001252) Muscular hypotonia Very frequent [Orphanet] 990 / 7739
68
(OMIM) Flat facial profile 6 / 7739
69
(OMIM) Broad, short hands 14 / 7739
70
(HPO:0012758) Neurodevelopmental delay Very frequent [Orphanet] 949 / 7739
71
(OMIM) Hypotonia, poor Moro reflex 1 / 7739
72
(HPO:0001428) Somatic mutation Very frequent [Orphanet] 100 / 7739
73
(HPO:0003745) Sporadic 131 / 7739
74
(OMIM) Leukemoid reactions 1 / 7739

Associated genes:

ClinVar (via SNiPA)

Gene symbol Variation Clinical significance Reference

Additional Information:

Description: (OMIM) Down syndrome, the most frequent form of mental retardation caused by a microscopically demonstrable chromosomal aberration, is characterized by well-defined and distinctive phenotypic features and natural history. It is caused by triplicate state (trisomy) of all or a ...
Diagnosis OMIM During the second trimester of pregnancy, serum alpha-feto protein (AFP; 104150) is commonly used for evaluating the risk of Down syndrome. Decreased levels of AFP are indicative of Down syndrome. However, Petit et al. (2009) noted that a ...
Clinical Description OMIM Down syndrome (Down, 1866), a particular combination of phenotypic features that includes mental retardation and characteristic facies, is caused by trisomy 21 (Lejeune et al., 1959), one of the most common chromosomal abnormalities in liveborn children.

...

Genotype-Phenotype Correlations OMIM Lyle et al. (2009) used array comparative genomic hybridization to analyze 30 patients with anomalies of chromosome 21, including 19 with partial trisomy 21 and 11 with partial monosomy 21, all for different segments of the chromosome. They ...
Molecular genetics OMIM - Genes Within the Down Syndrome Critical Region

Fuentes et al. (1995) cloned a gene (RCAN1; 602917), which they designated DSCR1, from the Down syndrome critical region that is highly expressed in brain and heart, and ...

Population genetics OMIM The frequency of trisomy 21 in the population is 1 in 650 to 1,000 live births (Hook, 1982).