Program Operations Manual System (POMS)
TN 69 (12-23)
COMPASSIONATE ALLOWANCES INFORMATION
|
MPS
I
|
ALTERNATE NAMES
|
Alpha-L-iduronate deficiency; Attenuated MPS I; Mucopolysaccharidosis type I; Hurler-Pfaundler
Syndrome; Hurler Syndrome; Hurler Syndrome Type IH; Hurler-Scheie Syndrome; Lipochondrodystrophy;
Pfaundler-Hurler Syndrome; Lysosomal Storage Disease – Mucopolysaccharidosis Type
I; MPS I H; MPS 1 H/S; MPS I S;
|
DESCRIPTION
|
MPS
I is one of a rare group of inherited diseases known as mucopolysaccharidoses. In this
syndrome, the body is unable to break down long chains of sugar molecules called glycosaminoglycans,
or mucopolysaccharides. The molecules are found throughout the body, often in mucus
and in fluid around the joints. Because the body is unable to make an enzyme called
lysosomal alpha-L-iduronidase, the sugar molecules build up and accumulate in blood
cells, cartilage, bone and connective tissues leading to permanent damage in multiple
body organs. MPS I is the most severe type of mucopolysaccharidosis. Symptoms can
range from mild to severe. Symptoms of MPS I most often appear between ages 3 and
8. Some individuals have skeletal and joint deformities that affect mobility.
|
DIAGNOSTIC TESTING, PHYSICAL FINDINGS, AND
ICD-9-CM/ICD-10-CM
CODING
|
Diagnostic testing:
-
•
Genetic testing for mutations in the alpha-L-iduronidase (IDUA) gene;
-
•
X-rays of the spine showing dysostosis multiplex;
-
•
Urine testing may reveal excess glycosaminoglycans (heparin sulfate/ dermatan sulfate);
-
•
Echocardiogram; pulmonary function testing;
-
•
EMG/ NCS nerve conduction studies;
-
•
CT scan/ MRI may be supportive; and
-
Physical findings: Individuals with this condition have:
-
•
Distinct facial features (flat face, depressed nasal bridge, bulging forehead);
-
-
•
Enlarged tongue (macroglossia) and vocal cords;
-
-
-
-
•
Enlarged liver and spleen (hepatosplenomegaly);
-
•
Leaky heart valves/enlarged heart;
-
•
Umbilical and inguinal hernia;
-
-
•
Hydrocephalus (buildup of fluid around brain);
-
•
Macrocephaly (large head); and
-
•
Cervical spinal stenosis (narrowing of spinal cord).
ICD-9: 277.5
ICD-10: E76.0
|
PROGRESSION
|
Infants may appear normal at birth. Signs most often appear between the ages of 6
and 24 months. The severe form is associated with rapid progression and decreases
in intellectual functioning, developmental delay and/ or regression, and death occurs
by age 10. Heart disease and pulmonary complications are the major causes of death.
|
TREATMENT
|
There is no cure for this disorder. Enzyme replacement therapy has been tried with
limited success. Bone marrow transplantation has also been attempted with mixed results.
Other treatment depends on the organs that are affected and are focused on improving
the individual’s quality of life.
|
SUGGESTED PROGRAMMATIC ASSESSMENT*
|
Suggested MER for Evaluation:
-
•
Clinical history and examination that describes the diagnostic features of the impairment;
-
•
Laboratory tests showing results of genetic testing for mutations in the IDUA gene;
-
•
Imaging studies, e.g. X-rays, CT scan/MRI
-
-
-
•
Pulmonary function testing;
-
•
EMG/ NCS nerve conduction studies; and
-
|
Suggested Listings for Evaluation:
|
DETERMINATION
|
LISTING
|
REMARKS
|
Meets
|
110.08 B
|
|
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.
|