RHIZOMELIC CHONDRODYSPLASIA PUNCTATA

RCDP; RCP; Chondrodysplasia Punctata Rhizomelic; Rhizomelic Chondrodysplasia Punctata Classic Type; Rhizomelic Chondrodysplasia Punctata Type 1; RCDP1; Rhizomelic Chondrodysplasia Punctata Type 2; RCDP2; Rhizomelic Chondrodysplasia Punctata Type 3; RCDP3

Rhizomelic Chondrodysplasia Punctata (RCDP) is a rare, inherited disorder that results in congenital skeletal abnormalities with shortening of proximal long bones, distinctive facial features, intellectual disability, and recurrent respiratory problems. Painful joint contractures, poor growth, cataracts developing in infancy, hearing loss, and seizures also occur frequently. Most children with this condition do not achieve developmental milestones such as sitting without support, feeding themselves, or speaking in phrases.

Diagnostic testing: The diagnosis is confirmed by biochemical or genetic testing of the gene mutation resulting in abnormal enzyme activity:

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  Type 1 -- peroxisomal enzyme function, including red blood cell concentration of plasmalogens (deficient), plasma concentration of phytanic acid (elevated), and plasma concentration of very long chain fatty acids (VLCFA) (normal) (PEX7);

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  Type 2 -- glyceronephosphate O-Acyl transferase (GNPAT);

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  Type 3 -- alkyldihydroxyacetonephosphate synthase (AGPS).

Physical findings:

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  Developmental delays;

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  Growth failure;

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  Cataracts;

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  Midface hypoplasia (prominent forehead, widely set eyes, sunken appearance of the middle of the face, small nose with upturned nostrils, and full cheeks);

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  Shortening of bones in upper extremities and femurs; and

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  Joint contractures.

ICD-9: 277.86

Most survive only into childhood; it is rare for an affected child to live past age 10. Death is usually caused by recurrent respiratory infections.

There is no current cure for RCDP. Treatment is supportive and many include physical therapy, anti-seizure medication, hearing amplification, and cataract removal.

SUGGESTED PROGRAMMATIC ASSESSMENT*

Suggested MER for Evaluation:

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  Clinical history and examination that describes diagnostic features of the impairment;

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  Genetic testing to confirm the diagnosis; and

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  Development assessment or psychological testing to address allegations of mental impairment.

Suggested Listings for Evaluation:

REMARKS