| Objective1.To explore detection rate from cytogenetical and genomic aspect in fetuses with CGIO.2.To compare the different detection rates between isolated CGIO group and complex CGIO group by CMA and karyotyping.3.To explore the relationship analysis of phenotype-genotype in the fetuses with CGIO by CMA.4.Follow-up was conducted for all fetal clinical outcomes.To provide a theoretical process of clinical prenatal diagnosis for CGIO fetuses.Methods1.From May 2012 and May 2019,203 fetuses with CGIO at the Prenatal Diagnostic Center of Guangzhou Women and Children's Medical Center were retrospectively collected in this study.They were divided into esophageal atresia/stenosis(n=27),duodenal atresia/stenosis(n=110),jejunal and ileal atresia/stenosis(n=38),large intestinal atresia/stenosis(n=28).According to the CGIO fetuses with or without other abnormalities by antenatal ultrasound,the samples were classified into 164 cases of isolated CGIO and 39 cases of non-isolated CGIO.2.According to clinical informed consent and comprehensive consideration of frozen samples,G-banding techniques and CMA as the first-tire testing were performed respectively.Those with negative karyotype results and abnormal karyotype structure were further analyzed by CMA.G-banding karyotype was performed basing on the standard experimental procedure.3.According to the manufacturer's protocol,Genomic DNA was extracted from amniotic fluid or cord blood of fetuses and peripheral blood of their parents using QIAamp? DNA Blood Mini kits.4.DNA samples of fetuses were run on CytoScanTM HD Array following the manufacturer's protocol.Array is scanned and generates intensity(CEL)file data,then the probe level analysis on CEL file data is analyzed with CHAS 2.0 software.5.The CNVs detected were further aligned with known CNVs listed in database at home and databases publically available online,such as the database of DECIPHER,OMIM,DGV,UCSC,ClinGen and ISCA.6.Through the hospital's system and telephone to follow-up,the pregnancy results of pregnant women were recorded,and the clinical outcomes of newborn babies were follow-up to 1 year old.7.The detection rate were completed by SPSS 22.0 software,only P<0.05 the difference makes sense.Results1.136 of 203 fetuses were performed on G-banding karyotyping.The detection rate was 11.0%(15/136).The abnormal karyotypes were trisomy 21(n=11),trisomy 18(n=2),46,XN,der(10)(n=1)and 13q21.2q31.1(n=1).The difference between the isolated CGIO and non-isolated CGIO was statistically significant [8.2%(9/110)vs 23.1%(6/26),p=0.029].2.28 of 121 fetuses with normal karyotypes and 1 fetus with abnormal karyotypes were further tested by CMA.We found that 1 fetus(3.6%)with pathogenic CNVs and 1 case with VOUS in samples with normal karyotype;and 1 fetus with abnormal karyotype also detected as pathogenic CNVs.3.CMA analysis as first-tier testing(without karyotyping)was applied in 67 fetuses.We found 6 fetuses(8.9%)with pathogenic CNVs and 2(3.0%)with VOUS.Among the cases with pathogenic CNVs,there were 3 aneuploidies,2 large deletions/duplications and 1 microdeletion.According to the Chi-square test,the difference between the detection rates of aneuploidies plus large deletions/duplications by CMA and standard karyotyping was not statistically significant(P=0.87).Similarly,the difference between the detection rates of microdeletions/ microduplications by CMA in fetuses without karyotyping and CMA in fetuses with normal karyotypes was not statistically significant(P=0.52).4.96 of 203 fetuses were performed by CMA,the detection rate in fetuses with isolated CGIO was 8.1%(6/74);and non-isolated CGIO was 9.1%(2/22).The difference was not statistically significant,though the latter one was slightly higher than the former(Fisher's test,P=0.885).and the highest detection rate of pathogenic CNVs was duodenal atresia/stenosis(15.7%,8/51),detection rate of other subgroups was zero.5.Of the 8 cases with pathogenic CNVs,there were 3 numerical abnormalities of chromosomes,1 known microdeletion syndromes(17q12 microdeletion syndromes),4 nonsyndromic CNVs including 13q21.33q31.1 deletion,13q21.32q22.3 deletion,13q21.2q31.1 deletion and 1q41q44 duplication.The 13 q deletion is likely related to duodenal atresia/stenosis,and the genes of HNF1 B and EDNRB were considered to be the candidate genes of causes of CGIO.6.Of 203 fetuses,181(89.2%)were successfully followed up,including 43 terminations,5 fetal deaths in utero,and 133 live births.Among the live births,96(72.2%,97/133)were successfully followed up,6 cases died,10 were excluded from gastrointestinal obstruction,and 83 survived after surgical treatment.Conclusion1.Chromosomal abnormalities in CGIO fetuses was 11%,which further demonstrated that digestive tract obstruction is associated with abnormal karyotypes,particularly those cases with other abnormalities.2.CMA plays an important role in clinical diagnosis of fetuses with CGIO,which can make clear origin,size and nature of unbalanced aberration.3.CMA can replace karyotype analysis in cases with CGIO,but CMA cannot detect balanced aberration and low proportion mosaic.What's more,the detection of VOUS increases the difficulty of clinical consultation.4.The risk of CNVs was different in different sites of digestive tract obstruction.In this study,the detection rate of pathogenic CNVs in duodenal stenosis/atresia was the highest.5.Duodenal atresia may be closely related to the absence of a segment of chromosome 13 q.6.Fetuses with CGIO and negative of chromosomal anomalies and CNVs,need to confirm the obstruction site and exclude other structural abnormalities after birth.An excellent prognosis can be expected. |
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