[Prenatal diagnosis and genetic analysis of 13 fetuses with 16p11.2 microdeletion/microduplication]

To explore the ultrasound finding, pregnancy outcome, and follow-up of fetuses with 16p11.2 microdeletion/microduplication to provide a basis for genetic counseling.

Thirteen fetuses with 16p11.2 microdeletion/microduplication detected by chromosomal microarray analysis (CMA) at the Genetic Testing Center of Women's and Children's Hospital Affiliated to Qingdao University between January 2021 and March 2024 were selected as study subjects. Prenatal ultrasound finding, results of genetic testing and family verification, pregnancy outcome, and postnatal conditions were retrospectively analyzed. Data were analyzed using descriptive statistical analysis. This study was approved by the Medical Ethics Committee of the hospital (Ethics No.: QFELL-YJ-2024-159).

Among 4 985 fetuses undergoing prenatal diagnosis, 13 (0.26%) were detected with 16p11.2 microdeletion/microduplication. Among these, 8 were microdeletions with a size ranging from 0.174 Mb to 0.84 Mb, and 5 were microduplications with a size ranging from 0.59 Mb to 0.89 Mb. The main prenatal ultrasound findings included cardiovascular abnormalities, vertebral developmental abnormalities, and nuchal translucency thickening. Parental tracing was performed in 12 of the 13 fetuses, with five cases verified to have a de novo origin, and seven originated from a phenotypically normal parent. Following genetic counseling, eight couples had opted induced labor, one couple with twin pregnancy had selected reduction of the abnormal fetus, whilst four couples had chosen to continue with the pregnancy. At follow-up, the liveborn infants were aged between 16 and 26 months, with one diagnosed with congenital heart disease, one with infantile epilepsy, and two showing no abnormality in growth and development.

CMA testing holds a significant value for the prenatal diagnosis of 16p11.2 microdeletion/microduplication. For fetuses with positive results, it is necessary to consult and conduct long-term follow-up in conjunction with prenatal ultrasound and parental tracing results in order to provide appropriate guidance for pregnancy decision and selection of reproductive methods.