GM2-gangliosidosis, AB variant

General Information (adopted from Orphanet):

Synonyms, Signs: TAY-SACHS DISEASE, AB VARIANT
AB VARIANT GM2-GANGLIOSIDOSIS
GM2 ACTIVATOR DEFICIENCY
hexosaminidase activator deficiency
Number of Symptoms 21
OrphanetNr: 309246
OMIM Id: 272750
ICD-10: E75.0
UMLs:
MeSH:
MedDRA:
Snomed:

Prevalence, inheritance and age of onset:

Prevalence: No data available.
Inheritance: Autosomal recessive inheritance
[Omim]
Age of onset:

Disease classification (adopted from Orphanet):

Parent Diseases: GM2 gangliosidosis
 -Rare genetic disease
 -Rare neurologic disease

Symptom Information: Sort by abundance 

1
 (HPO:0000618) Blindness 124 / 7739
2
 (HPO:0000741) Apathy 42 / 7739
3
 (HPO:0003470) Paralysis 11 / 7739
4
 (HPO:0001263) Global developmental delay 853 / 7739
5
 (HPO:0001276) Hypertonia 317 / 7739
6
 (HPO:0002267) Exaggerated startle response 42 / 7739
7
 (HPO:0000726) Dementia 131 / 7739
8
 (HPO:0001250) Seizures 1245 / 7739
9
 (HPO:0003495) GM2-ganglioside accumulation 2 / 7739
10
 (HPO:0002835) Aspiration 11 / 7739
11
 (HPO:0001252) Muscular hypotonia 990 / 7739
12
 (HPO:0002421) Poor head control 23 / 7739
13
 (HPO:0001324) Muscle weakness 859 / 7739
14
 (HPO:0008947) Infantile muscular hypotonia 482 / 7739
15
 (HPO:0010547) Muscle flaccidity 466 / 7739
16
 (OMIM) Gray-white area around the retinal fovea 1 / 7739
17
 (OMIM) Cherry red macula 1 / 7739
18
 (OMIM) Both Hexosaminidase-A and B present 1 / 7739
19
 (OMIM) Hypertonia late 3 / 7739
20
 (HPO:0000007) Autosomal recessive inheritance 2538 / 7739
21
 (OMIM) Hex-A activating factor defect 1 / 7739

Associated genes:

ClinVar (via SNiPA)

Gene symbol Variation Clinical significance Reference

Additional Information:

Description: (OMIM) The GM2-gangliosidoses are a group of disorders caused by excessive accumulation of ganglioside GM2 and related glycolipids in the lysosomes, mainly of neuronal cells. GM2-gangliosidosis AB variant is characterized by normal hexosaminidase A (HEXA; 606869) and hexosaminidase B ...
Clinical Description OMIM Sandhoff et al. (1971) referred to Sandhoff disease (268800) as variant 0 (since both hexosaminidases A and B are missing) and classic Tay-Sachs disease as variant B (since HEXA is absent but HEXB is present in increased amounts). ...
Molecular genetics OMIM By RT-PCR of the GM2A gene in a patient with deficiency of GM2-activator protein, Chen et al. (1999) detected some normal-sized cDNA and a smaller cDNA species, which was not seen in the RT-PCR products from normal controls. ...