Genetic analysis and prenatal diagnosis of 15q11-q13 microduplication syndrome

15q11-q13 microduplication syndrome, a genetic disorder caused by duplications in the 15q11-q13 region, has been associated with autism spectrum disorder (ASD); however, research on chromosome 15 microduplications is scarce. We explored the copy number variant (CNV) characteristics of 15q11-q13 microduplication syndrome, pathogenic mechanisms of ASD-related causative genes in this region, and factors affecting ASD development.

We performed laboratory investigations and data collection on seven cases of 15q11-q13 microduplications, comprising 5 prenatal and 2 postnatal cases, detected using chromosomal microarray analysis (CMA), comparing their CNV characteristics and clinical presentations.

Chromosomal karyotyping was not performed in one case, while the results for the others were normal. CMA revealed one case each of a microduplication at 15q11.2q13.3, 15q11.2, 15q13.2q13.3, 15q13.3, and three at 15q11.2q13.1, varying in size from 444 kb to 9.6 Mb. Of the seven confirmed cases, postnatal facial anomalies were present in two male patients (cases 5 and 6), with one exhibiting intellectual disability, speech delay, ASD features, and hypotonia. No significant abnormalities could be observed in the five female patients. Concerning the five prenatal cases, four exhibited an ultrasound testing suggestive of abnormality, one displayed no abnormality on the ultrasound, although the mother of the fetus had a history of adverse pregnancy outcomes. Finally, only case 5 displayed facial deformities after birth. The remaining four fetuses did not retain any abnormality during postnatal follow-up."

The 15q11-q13 region may be associated with an increased ASD risk, and its clinical phenotype may be related to sex. Our study presents detailed clinical features and molecular genetic data, providing important insights into the link between 15q duplications and ASD and diagnosing and treating the syndrome.