MECP2 DUPLICATION SYNDROME
Trisomy Xq28; Distal Duplication Xq; Telomeric Duplication Xq; Lubs-Arena Syndrome; Lubs X-linked Intellectual Deficit Syndrome; Intellectual Deficit X-linked Lubs Type
MECP2 Duplication Syndrome is a genetic disorder in which there is an extra copy of the MECP2 gene on the X chromosome in each cell, meaning only males are affected. This condition causes severe neurodevelopmental disorders characterized by infantile hypotonia (diminished muscle tone), spasticity, developmental delay, intellectual disability, poor speech development, progressive spasticity, recurrent respiratory infections, and seizures.
Approximately one third of individuals with this condition cannot walk without assistance; recurrent respiratory tract infections are also common.
DIAGNOSTIC TESTING, PHYSICAL FINDINGS, AND ICD-9-CM CODING
Diagnostic testing: The laboratory diagnosis of MECP 2 duplication syndrome is established by molecular genetic testing documenting duplications of Xq28, the chromosomal location of MECP 2.
Physical findings: Failure to thrive; difficulties with swallowing and feeding; gastroesophageal reflux; and abnormal muscle tone (ranging from hypotonia to spasticity).
ONSET AND PROGRESSION
Children with this disorder appear normal at birth. Shortly after birth, infants show signs of difficulties with feeding and swallowing resulting from hypotonia, gastro-esophageal reflux, failure to thrive, developmental delay, seizures, and recurrent respiratory infections. Respiratory infections and neurological deterioration are a major cause of death, with mortality occurring in half of affected individuals by age 25.
Medical management of children with MECP 2 duplication syndrome is supportive and planned on a case-by-case basis, depending on the individual circumstances. For example, physical and occupational therapies may be used to help relieve spasticity, maintain or increase muscle tone. A speech language pathologist may evaluate communication and swallowing problems. Assistive devices such as wheelchairs, helmet, and communication boards may be used for safety, and to improve quality of life. Anticonvulsive medications may be used to treat seizures. School age children may benefit from individualized educational planning.
SUGGESTED PROGRAMMATIC ASSESSMENT*
Suggested MER for evaluation:
Clinical history and physical examination that describes diagnostic features of the impairment and laboratory findings are needed to confirm the diagnosis.
Developmental assessment or psychological testing to address allegations of mental impairments may be warranted.
Suggested Listings for Evaluation:
Listing level neurological or cognitive changes must be documented; diagnosis or laboratory testing results alone do not meet listing severity.
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