16p13.11 microduplication in 14 fetuses: prenatal diagnosis and postnatal follow-up

16p13.11 Microduplication is a rare genetic disorder with variable expression and incomplete penetrance, primarily reported in adults and children, with limited information available on fetal cases. This study aims to analyze the characteristics of prenatal diagnosis indications and postnatal follow-up in fetuses with 16p13.11 microduplication, and to explore the genotype-phenotype correlation for improving genetic counseling and patients' care.

A total of 4552 pregnant women who underwent amniocentesis for SNP-array were retrospectively analyzed at the prenatal diagnosis department of Chengdu Women's and Children's Central Hospital from March 2022 to February 2024.

SNP-array identified a microduplication at the 16p13.11 region in 14 fetuses, with sizes ranging from 0.8 to 1.65 Mb. Among the indications for prenatal diagnosis, Case 1, 13, 14 (3/14) presented a high-risk screening result for Down syndrome, Case 5, 8, 10,11 (4/14) demonstrated advanced maternal age, Case 7 (1/14) demonstrated abnormal reproductive history, Case 4 (1/14) demonstrated the pregnant woman was a known carrier of the 16p13.11 microduplication, and Case 2, 3, 6, 9, 12 (5/14) demonstrated ultrasound structural abnormalities. Only 5/14 underwent family verification, and all were inherited from one parent. 2/14 chose to terminate pregnancy, while the remaining cases resulted in term delivery. During follow-up, all but three cases showed no significant abnormalities: one had severe sensorineural hearing loss, one exhibited mild developmental delay, and one was diagnosed with a ventricular septal defect.

These findings indicate that fetuses with 16p13.11 microduplication typically exhibit a nonspecific prenatal phenotype but may be highly correlated with ultrasound abnormalities. Most affected individuals were in good health during follow-up. Furthermore, a systematic review of medical history, genetic diagnosis, and follow-up data could be useful for genetic counseling and patients' growth management.

16p13.11; microduplication; SNP-array; prenatal diagnosis; follow-up.