KRABBE DISEASE (KD) - INFANTILE
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ALTERNATE NAMES
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Beta Galactocerebrosidase (GALC) Deficiency; Galactosylceramide Deficiency; Galactosylceramide
Lipidosis; Globoid Cell Leukodystrophy (GLD); Krabbe Leukodystrophy; Sphingolipidoses,
Krabbe Type
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DESCRIPTION
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Krabbe
disease
(KD) is a rare, inherited degenerative disorder of the central and peripheral nervous
systems. Krabbe disease is one of a group of genetic disorders called the leukodystrophies.
These disorders impair the growth or development of the myelin sheath, the fatty covering
that acts as an insulator around nerve fibers, and cause severe degeneration of mental
and motor skills. Myelin, which lends it color to the “white matter” of the brain,
is a complex substance made up of at least 10 different enzymes. Each of the leukodystrophies
affects one (and only one) of these substances. Krabbe disease is a lysomal storage
disease caused by a deficiency of galactocerebrosidase (GALC), an essential enzyme
for myelin metabolism.
Infantile form: This is the most common type and onset is almost always before six
months of age and even during the first week of life. The baby usually dies within
the first one or two years of life, most commonly due to infection and/or bulbar palsy.
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DIAGNOSTIC TESTING, PHYSICAL FINDINGS, AND
ICD-9-CM/ICD-10-CM
CODING
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Diagnostic testing: Before birth, a fetus can be screened for Krabbe disease. Using a needle, the doctor
can withdraw amniotic fluid surrounding the fetus, and then the cells in this fluid
can be examined in the lab. This requires obtaining fetal cells by chorionic villus
sampling or culturing amniotic fluid cells obtained by amniocentesis. After birth,
a physical exam of the child, evaluating signs and symptoms and diagnostic testing
including: blood, skin samples (biopsy), lumbar puncture (spinal tap), magnetic resonance
imaging (MRI) and computed tomography (CT) scans, nerve conduction studies, eye exam,
and genetic testing may be done to confirm the diagnosis.
Physical findings:
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Irritability and progressive stiffness (irritable-hypertonic presentation);
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Convulsions may be part of the symptoms.
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Increased muscle tone and pyramidal signs;
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Absent or weak deep tendon reflexes;
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Rapid deterioration in motor function, with chronic opisthotonos (severe muscle spasms)
and myoclonic jerking;
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Hyperpyrexia (extremely high body temperature), hypersalivation (excessive saliva
production), and hypersecretion (excessive production of mucus in the airways) from
the lungs; and
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Rapid and severe motor and mental deterioration.
ICD-9: 330.0
ICD-10: E75.23
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PROGRESSION
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Infantile Krabbe disease is generally fatal before age two. Prognosis may be significantly
better for children who receive umbilical cord blood stem cells prior to disease onset
or early bone marrow transplantation.
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TREATMENT
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There is no specific, proven treatment for advanced, symptomatic Krabbe disease. Treatment
at this stage is designed primarily to ease symptoms. For example, anticonvulsant
medications may be used to manage the seizures associated with this disease. Other
drugs may reduce the risk of vomiting. Some research indicates possible benefits associated
with the use of bone marrow transplantation or cord blood transfusion as treatments
for Krabbe disease. For presymptomatic infants and older individuals with mild symptoms,
hematopoietic stem cell transplantation (HSCT) with cord blood provides a benefit
over symptomatic treatment only.
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SUGGESTED PROGRAMMATIC ASSESSMENT*
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Suggested MER for Evaluation:
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Genetic testing of GALC gene (targeted mutation or sequence analysis);
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Enzyme assay for GALC enzyme activity;
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MRI or CAT scan with characteristic white matter abnormalities; and
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A description of motor findings (limb stiffness, spasticity, ataxia, progressive psychomotor
decline).
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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 A
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Krabbe disease - infantile form confirmed by genetic testing or enzyme assay. |
111.17
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11.17
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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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