POMPE
DISEASE - Infantile |
ALTERNATE NAMES
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Acid Maltase Deficiency (AMD); Alpha-1,4 Glucosidase Deficiency; Cardiomegalia Glycogenica
Diffusa; Generalized Glycogenosis (Cardiac); Glycogen Storage Disease type II; Glycogenosis
type II; Lysosomal Glucosidase Deficiency; Glycogen storage disease due to acid maltase
deficiency, infantile onset
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DESCRIPTION
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Pompe disease is a rare (estimated at 1 in every 40,000 births) inherited and often fatal disorder
that disables the heart and muscles. It is caused by mutations in a gene that makes
an enzyme called alpha-glucosidase (GAA). Normally, the body uses GAA to break down
glycogen, a stored form of sugar used for energy. But in Pompe disease, mutations
in the GAA gene reduce or completely eliminate this essential enzyme. Excessive amounts
of glycogen accumulate everywhere in the body, but the cells of the heart and skeletal
muscles are the most seriously affected. Researchers have identified up to 70 different
mutations in the GAA gene that cause the symptoms of Pompe disease, which can vary
widely in terms of age of onset and severity. The severity of the disease and the
age of onset are related to the degree of enzyme deficiency.
Infantile form occurs within the first months of life, with feeding problems, poor weight gain, muscle
weakness, floppiness, and head lag. Respiratory difficulties are often complicated
by lung infections. The heart is grossly enlarged. More than half of all infants with
Pompe disease also have enlarged tongues.
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DIAGNOSTIC TESTING, PHYSICAL FINDINGS, AND
ICD-9-CM/ICD-10-CM
CODING
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Diagnostic testing: A diagnosis of Pompe disease can be confirmed by screening for the common genetic
mutations or measuring the level of GAA enzyme activity in a blood sample - a test
that has 100 percent accuracy.
Physical
findings: Pompe disease usually presents within the first three months of life with:
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Rapidly progressive muscle weakness (floppy infants)
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Diminished muscle tone (hypotonia);
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Respiratory insufficiency;
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Large, protruding tongue (macroglossia);
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Enlarged liver (hepatomegaly); and
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Hypertrophic cardiomyopathy.
ICD-9: 271.0
ICD-10: E74.02
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PROGRESSION
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Most babies with the Infantile form of Pompe disease die from cardiac or respiratory complications before their first birthday. Without
enzyme replacement therapy, the hearts of babies progressively thicken and enlarge.
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TREATMENT
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There is no cure for Pompe disease. Treatment, therefore, serves only to help minimize
the symptoms. The clinical course is typically not affected by drugs that are used
to treat the respiratory or cardiac defects. A high protein diet may be helpful and
has led to significant improvements in respiratory function in some cases. An enzyme
replacement therapy has been developed that has shown, in clinical trials with Infantile
Pompe
disease, to decrease heart size, maintain normal heart function, improve muscle function,
tone, and strength, and reduce glycogen accumulation. A drug called alglucosidase
alfa (Myozyme), has received FDA approval for the treatment of Pompe disease.
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SUGGESTED
PROGRAMMATIC ASSESSMENT* |
Suggested MER for Evaluation: A diagnosis of Pompe disease can be confirmed by screening for the common genetic
mutations or measuring the level of GAA deficiency in a blood sample - a test that
has 100% accuracy.
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Suggested Listings for Evaluation: |
DETERMINATION
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LISTING
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REMARKS
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Meets |
104.02
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This listing should be considered when definitive genetic testing is available or
when the symptoms and signs that would meet this listing independent of the exact
diagnosis are present.
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110.08
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This listing should be considered when definitive genetic testing is available or
when the symptoms and signs that would meet this listing independent of the exact
diagnosis are present.
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111.17
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This listing should be considered when definitive genetic testing is available or
when the symptoms and signs that would meet this listing independent of the exact
diagnosis are present.
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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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