Intrauterine phenotypic features associated with 16p11.2 recurrent microdeletions.

Objective: To investigate the detection rate of 16p11.2 recurrent microdeletions in fetuses with abnormal ultrasound findings and determine the common abnormal ultrasound findings in fetuses carrying the deletion.

Methods: This study reviewed 2262 consecutive fetuses with abnormal ultrasound findings who underwent prenatal chromosomal microarray analysis between October 2014 and December 2016. Cases carrying the 16p11.2 recurrent microdeletion were further genetically analyzed, and their clinical features were reviewed.

Results: The 16p11.2 recurrent microdeletion was identified in 12 fetuses, who had skeletal malformations (5/12), cardiovascular malformations (4/12), or isolated ultrasound markers (3/12). Approximately 0.5% (12/2262) of the fetuses with abnormal ultrasound findings harbored the deletion. The 5 fetuses with skeletal malformations displayed vertebral defects, particularly in the hemivertebra and butterfly vertebra. The detection rate of the 16p11.2 recurrent microdeletion was statistically significant (P < .05) among fetuses with skeletal malformations (3.6%, 5/140), fetuses with cardiovascular malformations (1.1%, 4/367), and fetuses with isolated ultrasound markers (0.4%, 3/702).

Conclusion: The most frequent ultrasound findings in fetuses with 16p11.2 recurrent microdeletions are skeletal malformations (particularly vertebral malformations), followed by cardiovascular malformations, and isolated ultrasound markers.