NEONATAL ADRENOLEUKODYSTROPHY
|
ALTERNATE NAMES
|
Adrenoleukodystrophy Autosomal Neonatal Form; NALD; Neonatal ALD; PBD; Peroxisomal
Acyl-CoA Oxidase Deficiency; Peroxisomal Biogenesis Disorder; Pseudoadrenoleukodystrophy;
Pseudo-Neonatal Adrenoleukodystrophy; Straight-Chain Acyl-CoA Oxidase Deficiency;
Zellweger Syndrome Spectrum; ZSS
;
|
DESCRIPTION
|
Neonatal
adrenoleukodystrophy
(NALD) is a leukodystrophy that causes damage to the myelin sheath, an insulating membrane
that surrounds nerve cells in the brain (white matter). NALD also affects the adrenal
glands and the testes. NALD belongs to the Zellweger spectrum of peroxisome biogenesis
disorders (PBD, ZSS), is considered a moderately severe form and is caused by a mutation
of several PEX genes.
|
DIAGNOSTIC TESTING, PHYSICAL FINDINGS, AND
ICD-9-CM/ICD-10-CM
CODING
|
Diagnostic testing:
-
•
Biochemical abnormalities detected in the blood and/or urine should be confirmed in
cultured fibroblasts. The tests are used to detect accumulation of very long chain
fatty acids (VLCFS) and whether the serum pipecolic acid is elevated (this finding
helps differentiate NALD from X-ALD).
-
•
Blood studies may detect adrenal insufficiency.
-
•
MRI (magnetic resonance imaging) limited to the cerebellum may show defects in the
white matter of the brain.
-
•
ERG (electroretinogram) will be abnormal in those with retinal pigmentary degeneration.
-
•
Hearing tests may be abnormal.
-
•
Molecular genetic testing for mutations in the PEX genes.
Physical findings: Symptoms of NALD include:
-
-
-
•
Distinctive facial characteristics such as high forehead, a large anterior fontanelle,
broad nasal bridge, crossed eyes, deformed ear lobes, and skin folds;
-
•
Seizures and liver cysts with hepatic dysfunction; and
-
•
Bony stippling of the patella and other long bones.
The clinical course of NALD is variable and may include:
-
-
-
-
-
•
Episodes of hemorrhage and intracranial bleeding.
ICD-9: 277.86
ICD-10: E71.511
|
PROGRESSION
|
NALD is a serious disease with most children dying as infants or before three years
of age. While some children can be very hypotonic, others learn to walk and talk.
The condition is often slowly progressive and may include degeneration of the myelin
leading to loss of previously acquired skills and ultimately death. Children who survive
in the first year and who have a non-progressive course have a 77% probability of
reaching school age.
|
TREATMENT
|
There is currently no cure for this disease. Treatment is symptomatic and supportive
and may include feeding tubes, hearing aids, cataract removal, vitamin K and other
fat-soluble vitamin supplements, and other liver dysfunction therapies, and anti-epileptic
drugs to control seizures.
|
SUGGESTED PROGRAMMATIC ASSESSMENT*
|
Suggested MER for Evaluation:
-
•
Current complete clinical examination that describes diagnostic features and severity
of the impairment;
-
•
Plasma VLCFA abnormalities as outlined above or mutations in the PEX genes confirm a diagnosis of one of the PBD’s; and
-
•
If a PBD has not been confirmed by either biochemical or genetic testing, a complete
review of the clinical history, course and laboratory studies on which the disorder
is suspected will need to be undertaken. Differentiation of NALD from the other PBDs
will then depend on the other physical and laboratory findings.
|
Suggested Listings for Evaluation:
|
DETERMINATION
|
LISTING
|
REMARKS
|
Meets
|
110.08
|
|
Equals
|
|
|
* 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.
|