1q21.1 duplication syndrome

A genetic disorder caused by duplication of a region on chromosome 1

1q21.1 duplication syndrome is a genetic disorder caused by the duplication of a small region on the long arm of chromosome 1. This condition is associated with a variety of clinical features, which can vary widely among affected individuals.

Genetics

1q21.1 duplication syndrome is characterized by the presence of an extra copy of a segment of genetic material on chromosome 1, specifically at the 1q21.1 location. This duplication can be inherited in an autosomal dominant manner, meaning that a single copy of the duplicated region is sufficient to cause the disorder. However, the condition can also occur de novo, meaning it arises spontaneously without being inherited from a parent.

Diagram showing autosomal dominant inheritance.

Clinical Features

The clinical presentation of 1q21.1 duplication syndrome is highly variable. Some individuals with the duplication may be asymptomatic, while others may exhibit a range of symptoms. Common features include:

• Developmental delay
• Intellectual disability
• Autism spectrum disorder
• Congenital heart defects
• Microcephaly or macrocephaly
• Seizures

Diagnosis

Diagnosis of 1q21.1 duplication syndrome is typically made using genetic testing methods such as chromosomal microarray analysis or fluorescence in situ hybridization (FISH). These tests can identify the presence of the duplicated region on chromosome 1.

Management

There is no cure for 1q21.1 duplication syndrome, and treatment is generally supportive and symptomatic. Management may involve:

• Early intervention programs for developmental delays
• Special education services
• Speech therapy, occupational therapy, and physical therapy
• Medical management of associated conditions such as seizures or heart defects

Prognosis

The prognosis for individuals with 1q21.1 duplication syndrome varies depending on the severity of symptoms and associated conditions. Some individuals may lead relatively normal lives, while others may require ongoing medical and educational support.

Related pages

• Chromosome 1
• Genetic disorder
• Autosomal dominant
• Chromosomal microarray analysis

Gallery

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  Diagram showing the location of 1q21.1 on chromosome 1.

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  1q21.1 duplication syndrome
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  1q21.1 duplication syndrome