17p13.3 Microduplication syndrome

17p13.3 microduplication syndrome is a highly variable and difficult-to-define disorder due to its rarity and clinical heterogeneity. Its prevalence is estimated to be less than 1 in 1,000,000. The syndrome is mainly characterized by psychomotor developmental delay and distinctive facial features. Additional studies have reported intellectual disability, autism spectrum disorders, and occasionally structural brain abnormalities on MRI. Research involving 34 patients from 21 families identified shared neurological abnormalities, behavioral disturbances, and brain structural anomalies.

Clinical features:
Clinical manifestations are highly variable, making the syndrome difficult to characterize. Common features include mild to moderate psychomotor developmental delay, hypotonia, and characteristic facial features such as a high forehead with frontal bossing, a small nose, and a small mouth. Some patients present with a high-arched (Gothic) palate. Approximately one-third of patients show features of autism spectrum disorder. In older patients, overweight is commonly observed.

Etiology:
The syndrome is caused by a genetic abnormality in which a small segment of chromosome 17 is duplicated (a de novo duplication), leading to the clinical features of the disorder.

Diagnosis:
Genetic testing is indicated in cases of suspected genetic disorder, particularly in patients with psychomotor delay and hypotonia.

Treatment:
No causal treatment is available. Early rehabilitation is recommended due to psychomotor delay and hypotonia, along with early intervention programs and psychological support in cases of autism spectrum disorder.

• psychomotor developmental delay
• characteristic facial features: high forehead, small mouth, small nose, Gothic palate
• hypotonia (reduced muscle tone)
• intellectual disability
• autism spectrum disorders (ASD)
• overweight in adulthood
• structural brain abnormalities (MRI findings)