22q13

22q13 Deletion Syndrome

22q13 deletion syndrome, also known as Phelan-McDermid syndrome, is a genetic disorder caused by the deletion of a small piece of chromosome 22. The deletion occurs near the end of the chromosome at a location designated q13.

Symptoms and Signs

The symptoms of 22q13 deletion syndrome can vary widely among affected individuals. However, common symptoms include intellectual disability, delayed development, poor muscle tone (hypotonia), and problems with speech and communication. Many affected individuals also have autism spectrum disorder (ASD), which affects social interaction and communication.

Causes

22q13 deletion syndrome is caused by deletions of genetic material from the long arm (q) of chromosome 22. The deletions can vary in size but always include the SHANK3 gene. This gene is critical for the normal development of the nervous system, and its loss is believed to be responsible for many of the neurological symptoms of 22q13 deletion syndrome.

Diagnosis

Diagnosis of 22q13 deletion syndrome is based on clinical features and confirmed by genetic testing. This can include karyotyping, fluorescence in situ hybridization (FISH), or chromosomal microarray (CMA) analysis.

Treatment

There is currently no cure for 22q13 deletion syndrome. Treatment is symptomatic and supportive, and may include physical, occupational, and speech therapy, as well as educational support and behavioral therapy for those with ASD.

See Also

• Chromosome 22
• Genetic disorder
• Autism spectrum disorder
• SHANK3

NIH genetic and rare disease info

• NIH info on 22q13

22q13 is a rare disease.