Neuropsychiatric phenotypes and ASD features in 3q29 deletion syndrome

Neuropsychiatric phenotypes and a distinct constellation of ASD features in 3q29 deletion syndrome: results from the 3q29 registry

The phenotype of 3q29 deletion syndrome is characterized mainly by neurodevelopmental and psychiatric features. Usually this syndrome is caused by a de novo deletion, typically 1.6 Mb, on chromosome 3. Although, it is known that patients with 3q29 Del have an increased risk for autism spectrum disorder (ASD) and schizophrenia, prior studies have not fully described the ASD phenotype in 3q29 deletion syndrome. The authors in this paper sought to further examine the neuropsychiatric and neurodevelopmental phenotypes in 3q29 deletion syndrome.

The study consisted of 93 participants with 3q29 Del (obtained mainly from the internet-based deletion 3q29 registry) and a control group. Individuals with 3q29 Del were evaluated with self-reports and four standardized scales used to assess ASD symptoms. The authors found that individuals with 3q29 Del were more likely to report an ASD diagnosis, anxiety disorders, and had significantly elevated scores on all the ASD scales. In particular, females with 3q29 Del were found to be at a greater increased risk for ASD compared to males with 3q29 Del.

Further analysis of the results revealed some notable differences in the 3q29 Del study participants and children with idiopathic ASD. The 3q29 Del study participants scored significantly lower in impaired social motivation than the typical ASD profile. However, they had extremely high scores in the Restricted Interests and Repetitive Behaviors domains. Regardless of an ASD diagnosis, 3q29 Del individuals showed a very high degree of social disability compared to the control population.

The authors conclude that based on the study’s results that gold-standard ASD evaluations should be the recommended standard of care for individuals diagnosed with 3q29Del as early intervention may improve later outcomes.

Pollak RM, Murphy MM, Epstein MP et al. Neuropsychiatric phenotypes and a distinct constellation of ASD features in 3q29 deletion syndrome: results from the 3q29 registry. “Molecular Autism” 2019, v. 10:30.

Articles of the month are chosen from newly published genetic research by CDO geneticist, Dr. Iosif Lurie.  For more information on any article please contact info@chromodisorder.org