Parental origin of prenatally diagnosed pathogenic copy number variation in 56 pedigrees / 中华围产医学杂志

ABSTRACT

Objective:To investigate the prenatal management for pathogenic copy number variation (CNV) by analyzing the parental origin of CNV and pregnancy outcomes in 56 pedigrees.Methods:This study retrospectively analyzed the information of patients who received interventional prenatal diagnosis and chromosomal microarray analysis (CMA) at Guangzhou Women and Children's Medical Center from January 2015 to December 2020. The cases with pathogenic CNV indicated by CMA and receiving parental CMA for further verification were finally enrolled. Clinical data including prenatal diagnostic indications, chromosomal distribution of the pathogenic fragments and fragment sizes were collected and analyzed using t test. All cases were followed up by telephone and record review. Results:Fifty-six cases were included in this study. Pathogenic CNV in 13 (23.2%, 13/56) fetuses were inherited from one parent (eight from mothers and five from fathers), and mainly located in chromosomes 22 (3/13), 17 (3/11), 16 (2/7), 1 (2/4), and X (3/6) with fragment sizes all less than 3 Mb. The fragment size of inherited pathogenic CNV was significantly smaller than that of de novo CNV [1.69 (1.36-2.22) vs 7.54 (2.11-12.30) Mb, t=3.47, P=0.001]. Among the 43 cases with de novo pathogenic CNV, seven (16.3%) were lost to follow up and 35 (97.2%) terminated the pregnancy. The other one with a 0.58 Mb microruplication at 16p11.2 indicated at 37 gestational weeks gave birth to a baby weighting 2 900 g at 39 gestational weeks and no abnormalities were reported during an eight-month telephone follow-up. Two out of the 13 cases with inherited pathogenic CNV were lost to follow up and six pregnancies were terminated. The other five pregnancies were continued and babies were delivered with no abnormalities during a median follow-up period of 13 (4-15) months. Conclusion:Pathogenic CNV alone should not be the indication for pregnancy termination.