17q21.31 microdeletion syndrome

17q21.31 microdeletion syndrome is a rare genetic disorder characterized by a deletion of genetic material on the long arm (q) of chromosome 17 at a position designated q21.31. This syndrome is associated with a wide range of developmental and physical abnormalities. The condition is also known by several other names, including 17q21.31 deletion syndrome and monosomy 17q21.31.

Symptoms and Characteristics

The symptoms of 17q21.31 microdeletion syndrome can vary significantly among affected individuals. Common features include developmental delay, intellectual disability of varying degrees, distinctive facial features, and, in some cases, skeletal anomalies. Other potential symptoms may include seizures, muscle hypotonia (reduced muscle tone), and behavioral problems such as autism spectrum disorders.

Distinctive facial features often associated with this syndrome include a long face, high forehead, underdeveloped midface, and a prominent nasal bridge. However, it is important to note that the presence and severity of symptoms can vary widely.

Genetics

17q21.31 microdeletion syndrome is caused by a deletion of genetic material on chromosome 17 at the q21.31 region. This deletion includes several genes, but the deletion of the KANSL1 gene is thought to play a key role in the development of the syndrome. The syndrome is inherited in an autosomal dominant pattern, which means a deletion in just one copy of chromosome 17 in each cell is sufficient to cause the disorder. However, most cases result from de novo mutations and occur in people with no history of the disorder in their family.

Diagnosis

Diagnosis of 17q21.31 microdeletion syndrome is based on clinical evaluation and confirmed through genetic testing. Chromosomal microarray analysis (CMA) or whole-genome sequencing can detect the deletion of genetic material on chromosome 17. Early diagnosis is crucial for the management of symptoms and early intervention services.

Management and Treatment

There is no cure for 17q21.31 microdeletion syndrome, and treatment is symptomatic and supportive. Management may include physical therapy, occupational therapy, and speech therapy to help individuals achieve their full developmental potential. Educational support is also important. For specific symptoms such as seizures, appropriate medications may be prescribed. Regular follow-up with a team of healthcare providers is essential to address the various aspects of the syndrome.

Prognosis

The prognosis for individuals with 17q21.31 microdeletion syndrome varies depending on the severity of symptoms. With early intervention and supportive care, many individuals can lead fulfilling lives. However, the intellectual disability and developmental delays are typically lifelong conditions.

See Also

• Chromosome 17
• Genetic disorders
• Developmental delay
• Intellectual disability