Chromosome 22q13 duplication syndrome is a condition arising from an extra copy of genetic material in the terminal region of chromosome 22q13, primarily affecting neurological development. Individuals with this syndrome often present with seizures and delays in development, with global developmental delay and various behavioral challenges being common. The condition appears to occur sporadically, meaning that it typically arises in individuals with no prior family history, and precise prevalence estimates are not well established.

The clinical presentation of chromosome 22q13 duplication syndrome prominently features central nervous system involvement. Nearly all affected individuals experience bilateral tonic-clonic seizures, and many also suffer from status epilepticus. In addition, global developmental delay is observed along with challenges in attention, impulsivity, and emotional regulation, such as a short attention span, impulsivity, and emotional lability. Behavioral issues, including features of bipolar affective disorder and attention deficit hyperactivity disorder, highlight the cognitive and neurological impact of the syndrome. Distinctive facial features, such as anteverted nares, a narrow nasal ridge, epicanthus inversus, and upslanted palpebral fissures, are noted in a significant subset of patients. Not all individuals experience all features, and severity varies considerably.

The precise genetic basis of chromosome 22q13 duplication syndrome is still under investigation. Current evidence suggests that the condition occurs sporadically and is not typically inherited from a parent, which indicates that the duplication arises as a new genetic event. As genetic and environmental factors might play a role, genetic counseling is recommended to help families understand the implications and plan for future family building.