Mucolipidosis type 2

General Information (adopted from Orphanet):

Synonyms, Signs: ML II ALPHA/BETA
MUCOLIPIDOSIS II
ML II
ICD
i-cell disease
N-acetyl-glucosamine 1-phosphotransferase deficiency
Number of Symptoms 108
OrphanetNr: 576
OMIM Id: 252500
ICD-10: E77.0
UMLs: C0020725
C2931894
MeSH: C538602
MedDRA:
Snomed: 70199000

Prevalence, inheritance and age of onset:

Prevalence: 0.15 of 100 000 [Orphanet]
Inheritance: Autosomal recessive
[Orphanet]
Age of onset: Neonatal
[Orphanet]

Disease classification (adopted from Orphanet):

Parent Diseases: Lysosomal storage disease with skeletal involvement
 -Rare bone disease
 -Rare genetic disease
Mucolipidosis
 -Rare developmental defect during embryogenesis
 -Rare genetic disease

Symptom Information: Sort by abundance 

1
(HPO:0008155) Mucopolysacchariduria 6 / 7739
2
(HPO:0000343) Long philtrum Frequent [Orphanet] 262 / 7739
3
(HPO:0000280) Coarse facial features Very frequent [Orphanet] 189 / 7739
4
(HPO:0000463) Anteverted nares Frequent [Orphanet] 305 / 7739
5
(HPO:0100540) Palpebral edema 31 / 7739
6
(HPO:0002837) Recurrent bronchitis 21 / 7739
7
(HPO:0005280) Depressed nasal bridge Frequent [Orphanet] 381 / 7739
8
(HPO:0000535) Sparse and thin eyebrow 76 / 7739
9
(HPO:0000286) Epicanthus Frequent [Orphanet] 371 / 7739
10
(HPO:0002690) Large sella turcica 12 / 7739
11
(HPO:0000158) Macroglossia 119 / 7739
12
(HPO:0000348) High forehead 157 / 7739
13
(HPO:0002684) Thickened calvaria 32 / 7739
14
(HPO:0000187) Broad alveolar ridges Occasional [Orphanet] 14 / 7739
15
(HPO:0000341) Narrow forehead 96 / 7739
16
(HPO:0009092) Progressive alveolar ridge hypertropy 1 / 7739
17
(HPO:0007759) Opacification of the corneal stroma 77 / 7739
18
(HPO:0000485) Megalocornea 26 / 7739
19
(HPO:0001131) Corneal dystrophy Occasional [Orphanet] 56 / 7739
20
(HPO:0000481) Abnormality of the cornea Very frequent [Orphanet] 124 / 7739
21
(HPO:0000403) Recurrent otitis media 61 / 7739
22
(HPO:0001263) Global developmental delay 853 / 7739
23
(HPO:0011344) Severe global developmental delay 46 / 7739
24
(HPO:0012639) Abnormality of nervous system morphology Very frequent [Orphanet] 25 / 7739
25
(HPO:0006610) Wide intermamillary distance 46 / 7739
26
(HPO:0009769) Bullet-shaped phalanges of the hand 2 / 7739
27
(HPO:0003026) Short long bone 51 / 7739
28
(HPO:0002756) Pathologic fracture 30 / 7739
29
(HPO:0001762) Talipes equinovarus 309 / 7739
30
(HPO:0000882) Hypoplastic scapulae 28 / 7739
31
(HPO:0003311) Hypoplasia of the odontoid process 34 / 7739
32
(HPO:0001498) Carpal bone hypoplasia 17 / 7739
33
(HPO:0003019) Abnormality of the wrist Occasional [Orphanet] 52 / 7739
34
(HPO:0003016) Metaphyseal widening 41 / 7739
35
(HPO:0008470) Lower thoracic interpediculate narrowness 1 / 7739
36
(HPO:0000765) Abnormality of the thorax Very frequent [Orphanet] 64 / 7739
37
(HPO:0001171) Split hand 72 / 7739
38
(HPO:0003300) Ovoid vertebral bodies 21 / 7739
39
(HPO:0000924) Abnormality of the skeletal system Very frequent [Orphanet] 114 / 7739
40
(HPO:0004562) Beaking of vertebral bodies T12-L3 1 / 7739
41
(HPO:0000938) Osteopenia 138 / 7739
42
(HPO:0002827) Hip dislocation 94 / 7739
43
(HPO:0003414) Atlantoaxial dislocation 5 / 7739
44
(HPO:0002808) Kyphosis Occasional [Orphanet] 289 / 7739
45
(HPO:0001547) Abnormality of the rib cage 25 / 7739
46
(HPO:0003423) Thoracolumbar kyphoscoliosis 4 / 7739
47
(HPO:0006362) Varus deformity of humeral neck 1 / 7739
48
(HPO:0003180) Flat acetabular roof 25 / 7739
49
(HPO:0002869) Flared iliac wings 20 / 7739
50
(HPO:0001538) Protuberant abdomen 36 / 7739
51
(HPO:0002240) Hepatomegaly Very frequent [Orphanet] 467 / 7739
52
(HPO:0000023) Inguinal hernia 181 / 7739
53
(HPO:0001540) Diastasis recti 23 / 7739
54
(HPO:0001537) Umbilical hernia 206 / 7739
55
(HPO:0004299) Hernia of the abdominal wall Very frequent [Orphanet] 176 / 7739
56
(HPO:0001744) Splenomegaly Very frequent [Orphanet] 337 / 7739
57
(HPO:0001508) Failure to thrive 454 / 7739
58
(HPO:0008850) Severe postnatal growth retardation 16 / 7739
59
(HPO:0004322) Short stature Very frequent [Orphanet] 1232 / 7739
60
(HPO:0004325) Decreased body weight Occasional [Orphanet] 492 / 7739
61
(HPO:0000963) Thin skin Frequent [Orphanet] 96 / 7739
62
(HPO:0011362) Abnormal hair quantity Very frequent [Orphanet] 92 / 7739
63
(HPO:0100679) Lack of skin elasticity Frequent [Orphanet] 29 / 7739
64
(HPO:0001048) Cavernous hemangioma Occasional [Orphanet] 28 / 7739
65
(HPO:0001635) Congestive heart failure Occasional [Orphanet] 232 / 7739
66
(HPO:0001659) Aortic regurgitation 36 / 7739
67
(HPO:0001640) Cardiomegaly 81 / 7739
68
(HPO:0001639) Hypertrophic cardiomyopathy 137 / 7739
69
(HPO:0001654) Abnormality of the heart valves Occasional [Orphanet] 49 / 7739
70
(HPO:0003333) Increased serum beta-hexosaminidase 4 / 7739
71
(HPO:0003264) Deficiency of N-acetylglucosamine-1-phosphotransferase 3 / 7739
72
(HPO:0003538) Increased serum iduronate sulfatase activity 4 / 7739
73
(HPO:0003119) Abnormality of lipid metabolism Very frequent [Orphanet] 60 / 7739
74
(HPO:0006532) Recurrent pneumonia 48 / 7739
75
(HPO:0001609) Hoarse voice 34 / 7739
76
(HPO:0002205) Recurrent respiratory infections Occasional [Orphanet] 254 / 7739
77
(HPO:0001319) Neonatal hypotonia 101 / 7739
78
(OMIM) Tilted distal ends of radius and ulna 1 / 7739
79
(OMIM) Thick, relatively tight skin 1 / 7739
80
(OMIM) Brachyphalangia 1 / 7739
81
(OMIM) High, narrow forehead 1 / 7739
82
(OMIM) Birth length less than normal 1 / 7739
83
(OMIM) Hurler-like body configuration 1 / 7739
84
(OMIM) Increased serum arylsulfatase A (10-20x) 2 / 7739
85
(OMIM) Normal enlarged sella turcica 1 / 7739
86
(OMIM) Broad, spatulate-appearing ribs 1 / 7739
87
(OMIM) Thick, firm earlobes 1 / 7739
88
(OMIM) Osteopenia in early infancy 1 / 7739
89
(OMIM) Moderate joint limitation 1 / 7739
90
(OMIM) Supra-acetabular constriction 1 / 7739
91
(HPO:0000007) Autosomal recessive inheritance 2538 / 7739
92
(OMIM) Clear to faintly hazy corneas 1 / 7739
93
(OMIM) Irregular contours of pubis and ischium 1 / 7739
94
(HPO:0002196) Myelopathy 6 / 7739
95
(HPO:0012758) Neurodevelopmental delay Very frequent [Orphanet] 949 / 7739
96
(OMIM) Normal to mildly increased mucopolysacchariduria 1 / 7739
97
(MedDRA:10007586) Cardiac murmur 2 / 7739
98
(OMIM) Deceleration of linear growth during first year 1 / 7739
99
(OMIM) Progressive failure to thrive 1 / 7739
100
(OMIM) Broadening of wrist 1 / 7739
101
(OMIM) Birth weight less than normal 1 / 7739
102
(OMIM) Inclusion bodies (membrane-bound vacuoles) in fibroblasts 1 / 7739
103
(HPO:0003819) Death in childhood 42 / 7739
104
(OMIM) Lumbar gibbus 1 / 7739
105
(OMIM) Corneal opacities on slit-lamp examination 2 / 7739
106
(OMIM) Minimal splenomegaly 1 / 7739
107
(OMIM) Cortical bone erosion (especially proximal femora) 1 / 7739
108
(HPO:0030148) Heart murmur 29 / 7739

Associated genes:

ClinVar (via SNiPA)

Gene symbol Variation Clinical significance Reference

Additional Information:

Description: (OMIM) Mucolipidosis type II alpha/beta is an autosomal recessive disorder characterized clinically by short stature, skeletal abnormalities, cardiomegaly, and developmental delay. The disorder is caused by a defect in proper lysosomal enzyme phosphorylation and localization, which results in accumulation ...
Diagnosis OMIM Vidgoff et al. (1982) studied a population isolate with several couples at risk for ICD and concluded that carriers can be identified by serum levels of beta-D-hexosaminidase B (Vidgoff and Buist, 1977).

- Prenatal Diagnosis ...

Clinical Description OMIM Mucolipidosis II is a Hurler (607014)-like condition with severe clinical and radiologic features, peculiar fibroblast inclusions, and no excessive mucopolysacchariduria. Congenital dislocation of the hip, thoracic deformities, hernia, and hyperplastic gums are evident soon after birth. Retarded psychomotor ...
Genotype-Phenotype Correlations OMIM Otomo et al. (2009) identified 18 GNPTAB mutations, including 14 novel mutations, among 25 unrelated Japanese patients with ML II and 15 Japanese patients with ML III. The most common mutations were R1189X (607840.0004), which was found in ...
Molecular genetics OMIM Canfield et al. (1998) found that in 4 of 4 patients with mucolipidosis II, the GNPTA transcript was absent. In 2 of 2 patients with mucolipidosis IIIA, the GNPTA transcript was present but greatly reduced. In all ML ...
Population genetics OMIM In the French-Canadian population of the Saguenay-Lac-Saint-Jean region of Quebec province, De Braekeleer (1991) estimated the prevalence at birth of ML II to be 1/6,184, giving a carrier frequency of 1/39.

In 27 parents of 16 ...

Diagnosis GeneReviews The following clinical features contribute to early diagnosis of mucolipidosis II (ML II) but are not by themselves diagnostic (Figure 1):...
Clinical Description GeneReviews Mucolipidosis II (ML II) or I-cell disease is a slowly progressive inborn error of metabolism with clinical onset at birth and fatal outcome most often in early childhood [Cathey et al 2010]. The phenotype as described by system is summarized in this section....
Genotype-Phenotype Correlations GeneReviews GNPTAB sequencing has been available since 2005; however, the overall results of several studies have confirmed that homozygous and compound heterozygous genotypes that produce no or nearly no functional GlcNAc-1-phosphotransferase activity (caused by premature translation termination and/or frameshift effects) result in the ML II phenotype. The combination of less “morbid” mutations, such as missense and most of the splice-site mutations that result in up to 10% of residual GlcNAc-1-phosphotransferase activity, often yield the more slowly evolving ML III alpha/beta phenotype with later clinical onset [Paik et al 2005, Tiede et al 2005, Bargal et al 2006, Kudo et al 2006, Encarnaçao et al 2009, Otomo et al 2009, Tappino et al 2009, Cathey et al 2010, David-Vizcarra et al 2010, Cury et al 2011]....
Differential Diagnosis GeneReviews Findings in mucolipidosis II (ML II) overlap those observed in the more prevalent Hurler disease (mucopolysaccharidosis type I H). Compared to ML II, MPS I is associated with more signs of storage on physical examination and less severe dysostosis multiplex on radiographs. Biochemical testing distinguishes the two conditions unequivocally....
Management GeneReviews In order to establish the extent of disease in a child diagnosed with mucolipidosis II (ML II), the following evaluations are recommended:...
Molecular genetics GeneReviews Information in the Molecular Genetics and OMIM tables may differ from that elsewhere in the GeneReview: tables may contain more recent information. —ED....