22q13 deletion syndrome

22q13 Deletion Syndrome

Chromosome 22, where the deletion occurs in 22q13 deletion syndrome.

22q13 Deletion Syndrome, also known as Phelan-McDermid Syndrome, is a genetic disorder caused by the deletion of a segment on the long arm (q arm) of chromosome 22. This condition is characterized by a range of developmental, neurological, and physical symptoms.

Genetic Basis

The syndrome results from the deletion of genetic material on the distal end of chromosome 22, specifically at the 22q13 location. The size of the deletion can vary among individuals, leading to a spectrum of clinical manifestations. The SHANK3 gene, located in this region, is often implicated in the disorder, and its loss is associated with many of the neurological features observed in affected individuals.

Clinical Features

Individuals with 22q13 deletion syndrome may exhibit a variety of symptoms, including:

• Global developmental delay
• Intellectual disability
• Speech delay or absence of speech
• Hypotonia (low muscle tone)
• Autism spectrum disorder-like behaviors
• Epilepsy
• Sleep disturbances
• Feeding difficulties

Physical features may include:

• Dysmorphic facial features
• Large, fleshy hands
• Dolichocephaly (elongated head)
• Prominent ears

Diagnosis

Diagnosis of 22q13 deletion syndrome is typically confirmed through genetic testing, such as chromosomal microarray analysis or fluorescence in situ hybridization (FISH), which can detect the deletion on chromosome 22. Early diagnosis is crucial for managing symptoms and providing appropriate interventions.

Management

There is no cure for 22q13 deletion syndrome, but management focuses on addressing the individual symptoms and improving quality of life. This may include:

• Speech therapy
• Occupational therapy
• Physical therapy
• Behavioral interventions
• Educational support

Related Pages

• Chromosome 22
• Genetic disorders
• Intellectual disability
• Autism spectrum disorder

Gallery

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  Chromosome 22