ALTERNATE NAMES

Chromosome 1p36 deletion syndrome; Del(1)(p36); Deletion 1p36; Deletion 1pter; Lethal 1p36.33 deletion syndrome; Monosomy 1p36; Monosomy 1p36 syndrome; Monosomy 1pter; Subtelomeric 1p36 deletion

DESCRIPTION

1p36 Deletion Syndrome is a rare chromosome disorder that typically causes severe intellectual disability. Most individuals do not speak or speak only a few words. They may have temper tantrums, bite themselves, or exhibit other behavior problems. More than half of individuals with this disorder have structural abnormalities of the brain and experience seizures.

1p36 deletion syndrome is caused by a deletion of genetic material from a specific region in the short (p) arm of chromosome 1. Most cases are not inherited; only about 20% of the cases of people with 1p36 deletion syndrome inherit the chromosome with a deleted segment from an unaffected parent. In these cases, the parent carries a balanced translocation, in which no genetic material is gained or lost.

DIAGNOSTIC TESTING, PHYSICAL FINDINGS, AND ICD-9-CM/ICD-10-CM CODING

Diagnostic testing: The diagnosis of 1p36 deletion syndrome is made by:

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  Fluorescence in situ hybridization (FISH);

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  Comparative genomic hybridization array;

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  Echocardiogram;

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  Electrocardiogram (ECG);

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  Magnetic resonance imaging (MRI);

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  Electroencephalogram (EEG);

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  Neurodevelopmental assessment; and

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  Standard examinations for eye/vision problems, hearing loss, and skeletal and renal abnormalities.

Physical findings: Individuals with 1p36 deletion may have:

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  Weak muscle tone (hypotonia);

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  Swallowing difficulties (dysphagia);

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  A small head that is unusually short and wide (microbrachycephaly);

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  Vision problems;

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  Hearing loss (sensorineural or conductive/glue ear);

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  Abnormalities of the brain, skeleton, heart, gastrointestinal system, kidneys, or genitalia;

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  Hypothyroidism; and

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  Distinctive facial features.

ICD-9:758.9

ICD-10:Q93.5

PROGRESSION

Individuals with 1p36 syndrome survive well into adult life.

The progression of 1p36 deletion syndrome varies between affected individuals. Seizures and other medical issues seem to improve with time. Individuals diagnosed with this disorder will remain dependent on others for most activities of daily living and will require medical support throughout life.

TREATMENT

The management of 1p36 deletion syndrome should be multi-disciplinary and include regular follow-ups. Early diagnosis and access to personalized rehabilitation therapies focusing on motor development, cognition, communication, and social skills are highly recommended. The use of sign language is helpful. Some congenital heart defects may resolve on their own, others may require medication or surgery. Epileptic seizures are treated with standard antiepileptic medications. Infantile spasms are responsive to corticotrophin. Feeding and growth should be monitored as feeding difficulties are common in infancy and early childhood.

Suggested MER for Evaluation:

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

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  Results of FISH testing;

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  Results of imaging (echocardiogram, ECG, MRI, EEG); or

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  Results of neurodevelopmental assessment.

Suggested Listings for Evaluation:

DETERMINATION

LISTING

REMARKS

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