泌尿生殖系统超声对胎儿先天性泌尿生殖系统异常的临床应用价值

Clinical value of fetal genitourinary system ultrasonography in diagnosis of congenital anomalies of the kidney and urinary tract

目的探讨泌尿生殖系统超声在胎儿先天性泌尿生殖系统异常(CAKUT)中的临床应用价值,并分析其指导产前遗传学诊断的临床意义。方法回顾性收集2016年1月至2020年12月在南京医科大学附属淮安第一医院进行产前系统筛查发现的125例CAKUT胎儿病例。根据是否合并其他结构异常分为孤立性CAKUT组与非孤立性CAKUT组。对CAKUT胎儿进行定期随访,对遗传学结果及妊娠结局进行分析。采用χ2检验比较孤立性CAKUT组与非孤立性CAKUT组妊娠结局和遗传学结果的差异。结果胎儿泌尿生殖系统超声随访中发现17例肾盂扩张的病例分别于晚孕期及产后6个月内自愈;41例病例异常持续存在,但未出现临床症状,生长发育均良好;2例误诊;1例漏诊;4例病情加重于出生后1年内死亡,2例肾盂扩张(包括漏诊的1例)随访至出生6个月,具有手术指征,行手术治疗;48例行泌尿生殖系统超声检查再次确诊后家属选择终止妊娠,11例失访。68例样本行产前遗传学检查,染色体微阵列分析(CMA)发现11例(11/68,16.2%)遗传学结果异常,包括:4例染色体非整倍体异常,8例基因组拷贝数变异(其中1例同时存在染色体非整倍体异常和基因组拷贝数变异);其中非孤立性CAKUT组(25.0%,3/12)遗传学结果异常检出率高于孤立性CAKUT组(14.3%,8/56),但差异无统计学意义(χ2=0.837,P=0.360);另外10例CMA检查未见异常的胎儿样本行全外显子测序,检出1例表型为巨膀胱胎儿携带遗传自母亲的AQP2基因杂合变异,致病位点为c.559C>T(p.Arg187Cys),判定为致病性。结论泌尿生殖系统超声检查作为胎儿产前系统结构筛查超声的补充,有利于提高CAKUT诊断精准率,减少漏、误诊率,进一步指导产前诊断及胎儿远期预后评估。

Objective To assess the clinical value of genitourinary system ultrasonography in the diagnosis of congenital anomalies of the kidney and urinary tract(CAKUT),and to analyze the clinical significance of fetal genitourinary system ultrasound in guiding prenatal genetic diagnosis.Methods One hundred and twenty-five fetuses with CAKUT were reviewed and followed periodically by genitourinary system ultrasonography at the Prenatal Diagnostic Center of Huai’an First Hospital Affiliated to Nanjing Medical University from January 2016 to December 2020.They were divided into an isolated CAKUT group and a non-isolated CAKUT group according to whether other structural anomalies were combined.And their genetic results and pregnancy outcomes were analyzed.Theχ2 test was used to compare the difference of pregnancy outcome and genetic outcome between the isolated CAKUT group and the non-isolated CAKUT group.Results Ultrasonoimagedata follow-up of the fetal genitourinary system showed that 17 cases of pyelectasis were found to be self-healing in late pregnancy or 6 months after delivery.There were 41 cases with persistent abnormality but without clinical symptoms,and all of them had good growth and development.There were two cases of misdiagnosis and one case of missed diagnosis.Four cases died of aggravation within 1 year after birth,and two cases with pyelectasis(including 1 case with missed diagnosis)were followed to 6 months after birth,showing indications for surgery and receiving surgical treatment.Forty-eight families chose to terminate pregnancy after rediagnosis by genitourinary system ultrasound,and 11 cases were lost to follow-up.Prenatal genetic examination was performed in 68 samples,and chromosome microarray analysis(CMA)revealed abnormal genetic results in 11(11/68,16.2%)cases,including four cases of chromosome aneuploidy abnormality and eight cases of genome copy number variation(one of which had both chromosome aneuploidy and genome copy number variation).The detection rate of genetic abnormalites in the non-isolated CAKUT group(25.0%,3/12)was higher than that of the isolated CAKUT group(14.3%,8/56),but the difference was not significant(χ2=0.837,P=0.360).In addition,10 fetal samples with no abnormal CMA were tested by whole exon sequencing,and one fetus with macrobladder phenotype was detected to carry a heterozygous AQP2 gene mutation inherited from the mother:c.559C>T(p.Arg187Cys),which was judged to be pathogenic.Conclusion Genitourinary system ultrasonography examination of CAKUT,as a supplement to fetal system/structure screening,is obviously conducive to improving the accuracy of CAKUT diagnosis,reducing the rate of misdiagnosis and missed diagnosis and helping guide prenatal diagnosis and long-term prognosis evaluation of the fetus.