Congenital Myopathy with Excess of Muscle Spindles; Faciocutaneoskeletal Syndrome; FCS Syndrome

Costello syndrome is a rare condition that affects many different parts of the body. Costello syndrome belongs to the RASopathies, a group of conditions resulting from germline derived point mutations affecting the RAS-mitogen activated protein kinase pathway.

Signs and symptoms generally include developmental delay, intellectual disability, distinctive facial features, loose folds of extra skin (especially on the hands and feet), and unusually flexible joints. Cardiac and neurological involvement is common and there is an increased lifetime risk of certain tumors.

Diagnostic testing: Costello syndrome diagnosis occurs in early childhood. The diagnosis of Costello syndrome is made by:

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  Physical examination;

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  Genetic testing; and

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  Family medical history.

Physical findings: Symptoms of Costello syndrome include:

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  Feeding difficulties during infancy that sometimes require a feeding tube;

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  Heart problems (arrhythmia, hypertrophic cardiomyopathy);

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  Curve of the spine (scoliosis or kyphosis);

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  Intellectual disability (mild to moderate) and growth abnormalities of the brain (Chiari malformation);

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  Vision and dental problems;

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  Structural kidney differences; and

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  Weak muscle tone (hypotonia).

ICD-9:759.89

ICD-10:Q87.8, Q87.89

Costello syndrome is a lifelong condition without a cure. The prognosis varies by the specific missense mutations, with neonatal lethal phenotypes and attenuated phenotypes reported. The disorder progresses with age and children often show signs of premature aging, osteoporosis, and osteopenia. An increased risk of about 10 to 15 percent for solid malignant tumors (embryonal rhabdomyosarcoma, neuroblastoma) in early childhood and transitional cell carcinoma of the bladder in adolescence is reported.

Treatment for Costello syndrome addresses symptoms of the condition since there’s no cure. Treatment is directed toward the specific symptoms that are apparent in each child.

Pediatricians, cardiologists, orthopedists, orthopedic surgeons, dermatologists, speech pathologists, dietitians, and other health care professionals may need to plan an affected child’s treatment systematically and comprehensively.

Suggested MER for Evaluation:

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  Physical examination;

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  Family medical history; and

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  Genetic testing to determine the gene change responsible.

Suggested Listings for Evaluation:

REMARKS

Listing level severity must be documented.