Prenatal phenotypes and pregnancy outcomes of fetuses with 17p12 microdeletions and microduplications

To investigate the correlation between 17p12 copy number variations (CNVs) and prenatal phenotypes by analyzing clinical and molecular data from prenatal cases. Eighteen prenatal amniotic fluid samples diagnosed with 17p12 microdeletions/microduplications were obtained from pregnant women who chose invasive prenatal testing from October 2018 to September 2024. Karyotypic analysis and chromosomal microarray analysis (CMA) were carried out concurrently for all these cases. The pregnancy outcomes and postnatal health conditions of all cases were recorded. Meanwhile, we conducted a comprehensive analysis of the prenatal phenotypes in the published cases involving 17p12 CNVs. The overall detection rate of 17p12 CNVs was 0.14% (18/13,052). Ten fetuses were identified with 17p12 deletions, and eight with 17p12 duplications. The deletions ranged from 1.38 Mb to 1.46 Mb and duplications ranged from 1.32 Mb to 1.34 Mb, with the PMP22 , TEKT3 , and COX10 genes involved in the overlapping region. Prenatal ultrasound anomalies were observed in five cases, including four 17p12 deletions and one duplication. These anomalies included increased nuchal translucency (NT), urinary system abnormalities, respiratory system abnormalities, and cardiovascular abnormalities. In addition, 6/18 cases presented high risk of non-invasive prenatal testing (NIPT). All cases gave birth to healthy child at term. Increased NT and cardiovascular abnormalities were the recurrent ultrasound findings observed in cases with 17p12 deletions. 17p12 duplications exhibited diverse and non-specific ultrasound abnormalities. The combined application of NIPT and CMA is effective in detecting 17p12 CNVs in prenatal settings. For postnatal cases carrying 17p12 CNVs, long-term follow-up should be guaranteed till adulthood in case abnormal developmental phenotypes emerge in future.