染色体微阵列联合全外显子测序技术在胎儿生长受限产前诊断中的应用价值OA

Objectives:To exploring the application value of combining chromosomal microarray analysis(CMA)with whole exome sequencing(WES)in the prenatal diagnosis of fetal growth restriction(FGR). Methods:A total of 47 fetuses with FGR who underwent interventional prenatal diagnosis at the General Hospital of Northern Theater Command between January 2022 and April 2025 were selected.Cases were stratified by the gestational age at initial diagnosis into the group＜28 weeks(n=24)and one between 28 to 31+6 weeks(n=23).Further classification was based on the presence of additional ultrasound abnormalities:isolated FGR(n=32)and FGR with other ultrasound abnormalities(n=15).All cases underwent concurrent CM A and WES testing.Prenatal diagnosis outcomes were analyzed,and genetic abnormality detection rates across groups were compared. Results:As for the overall detection rates,CM A detected chromosomal abnormalities in 9 cases,including 5 pathogenic copy number variations(CNVs)and 4 of unknown clinical significance.WES identified genetic variations in 19 cases,comprising 11 pathogenic/probably pathogenic(P/LP)variations and 8 of unknown clinical significance with 3 of the latter exhibiting incomplete penetrance.Pathogenic CNVs detected by CMA were concurrently identified by WES,whereas WES failed to detect clinically ambiguous CNVs identified by CMA.The WES abnormality detection rate was significantly higher than that of CMA(P＜0.05),but showed no statistically significant difference compared to the combined CMA-WES detection rate(P＞0.05).Regarding the comparison by gestational age group,the detection rate of P/LP variation in the group＜28 weeks was significantly higher than that in the group between 28 to 31+6 weeks(P＜0.05).As for the comparison by FGR subtype,both the detection rate of genetic abnormalities and the detection rate of P/LP variation in the group with FGR combined with other ultrasound abnormalities were significantly higher than those in the isolated FGR group(P＜0.05). Conclusions:Performing CMA and WES on fetuses with a confirmed diagnosis of FGR can increase the detection rate of pathogenic/suspected pathogenic genetic variants.For clinically diagnosed FGR cases,if gestational age is less than 28 weeks and/or accompanied by ultrasound structural abnormalities,CM A is recommended as the primary test.If CMA results are negative,WES is recommended as a supplement.For fetuses with FGR between 28 and 31+6 weeks gestation,combined CMA and WES testing is recommended as the primary approach.If significant financial constraints exist,WES testing alone may be selected.