Program Operations Manual System (POMS)
TN 54 (09-22)
DI 23022.186 GM1 - Gangliosidosis - Infantile & Juvenile Forms
COMPASSIONATE ALLOWANCES INFORMATION
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GM1 - GANGLIOSIDOSIS - INFANTILE & JUVENILE FORMS
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ALTERNATE NAMES
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GM1 gangliosidosis type I; GM1 gangliosidosis type II; beta-galactosidase-1 (GLB1)
deficiency; GLB1 deficiency; Landing disease; type 1 GM1 gangliosidosis; type 2 GM1
gangliosidosis; Beta-galactosidosis; Classic infantile (type 1) GM1 gangliosidosis;
Juvenile (type 2) GM1 gangliosidosis
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DESCRIPTION
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GM1 gangliosidosis is a rare lysosomal storage disorder characterized biochemically by deficient beta-galactosidase
activity and clinically by a wide range of variable neurovisceral, ophthalmological,
and dysmorphic features.
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DIAGNOSTIC TESTING, PHYSICAL FINDINGS, AND ICD-9-CM/ICD-10-CM CODING
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Diagnostic testing: Diagnosis may be difficult due to the wide clinical spectrum of the disease. Diagnosis
is confirmed by:
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Biochemical assay of beta-galactosidase activity and/or by molecular genetic testing;
and
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A secondary combined defect of both GLB1 and neuraminidase (NEU1) has to be excluded.
Other diagnostic testing includes:
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Peripheral blood smear (testing vacuolated lymphocytes);
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Urine oligosaccharides; and
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Physical findings: Physical findings for types 1 and 2 GM1 gangliodosis may include:
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Gingival hypertrophy (enlarged gums);
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Cardiomyopathy (enlarged, weakened heart muscle);
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Enlarged organs inside of the abdomen, including liver, spleen, stomach, kidneys,
or pancreas (visceromegaly);
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Abnormal development of bones (dysostosis);
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Developmental regression;
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Difficulties with speech; and
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ICD-9: 277.89
ICD-10: E75.19
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PROGRESSION
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Infants with Type 1 GM1 gangliosidosis typically appear normal until around 6 months
of age when their development slows and muscles used for movement weaken. Affected
children typically do not live past 2 years of age.
Type 2 GM1 gangliosidosis consists of intermediate forms of the condition, also known
as the late infantile and juvenile forms. Children with GM1 gangliosidosis type 2
have normal early development, but they begin to develop signs and symptoms of the
condition around the age of 18 months (late infantile form) or 5 years (juvenile form).
Infants with GM1 gangliosidosis type 2 experience developmental regression but usually
do not have cherry-red spots, distinctive facial features, or enlarged organs. Type
2 usually progresses more slowly than type 1, but still causes a shortened life expectancy.
Children with the late infantile form typically survive into mid-childhood, while
those with the juvenile form may live into early adulthood.
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TREATMENT
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Treatment for GM1 gangliosidosis is symptomatic and supportive. Substrate reduction
therapy is a potential approach for clinical trials in late-onset forms. Prognosis
depends on the type of GM1 gangliosidosis and is extremely poor in the severe infantile
form.
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SUGGESTED PROGRAMMATIC ASSESSMENT*
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Suggested MER for Evaluation:
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Clinical history and examination that describes diagnostic features of the impairment;
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Results of genetic testing confirming diagnosis of the impairment; and
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Definitive results of other diagnostic testing.
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Suggested Listings for Evaluation:
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DETERMINATION
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LISTING
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REMARKS
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Meets
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110.08 B
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111.02
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111.09
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112.08
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112.14
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Equals
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* Adjudicators may, at their discretion, use the Medical Evidence of Record or the
listings suggested to evaluate the claim. However, the decision to allow or deny the
claim rests with the adjudicator.
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