Xiang Lina, Deng Anqi, Zhou Jie, Dong Xuefan, Mu Wenbo, Zhang Qi, Zhang Jing, Tang Sha, Fang Ping, Cai Xiaoqiang
KingMed Diagnostics, Guangzhou, Guangdong, China.
J Hum Genet. 2025 Jul 24. doi: 10.1038/s10038-025-01373-7.
Genetic defects are a major cause of pregnancy loss, leading to fetal death or elective abortion due to congenital anomalies. This study evaluates the effectiveness of trio exome sequencing (ES) in identifying genetic causes of pregnancy loss. Trio ES was used as a first-tier genetic test on 193 cases of pregnancy loss to detect both chromosomal abnormalities and small variants potentially linked to fetal death and anomalies. The pathogenicity of identified variants was assessed, and the diagnostic yield was analyzed. Trio ES provided an overall diagnostic yield of 24% (47/193) across this cohort, with a similar positive rate observed in fetal death (26%, 12/45) and elective abortion (23%, 35/148) groups. Among diagnosed cases, 45% (21/47) were attributed to chromosomal abnormalities, while 55% (26/47) were caused by small variants. This suggests that ES more than doubled the positive rates compared to traditional methods such as karyotyping and chromosomal microarray analysis. Notably, chromosomal abnormalities were the primary cause of fetal death (75%, 9/12), whereas small variants were more prevalent in elective abortion cases (68%, 24/35), particularly those with central nervous and skeletal anomalies. Additional candidate variants were identified in 35 inconclusive cases (18%), potentially further increasing the detection rate. This study highlights the value of trio ES in diagnosing genetic causes of pregnancy loss. Implementing it as a first-tier test can significantly enhance our understanding of fetal death and anomalies, therefore facilitating informed future pregnancy management.
基因缺陷是妊娠丢失的主要原因,可导致因先天性异常而出现胎儿死亡或选择性流产。本研究评估三联体全外显子测序(ES)在识别妊娠丢失的遗传原因方面的有效性。三联体全外显子测序被用作193例妊娠丢失病例的一线基因检测,以检测染色体异常以及可能与胎儿死亡和异常相关的小变异。对已识别变异的致病性进行了评估,并分析了诊断率。在这一队列中,三联体全外显子测序的总体诊断率为24%(47/193),在胎儿死亡组(26%,12/45)和选择性流产组(23%,35/148)中观察到相似的阳性率。在确诊病例中,45%(21/47)归因于染色体异常,而55%(26/47)由小变异引起。这表明与传统方法如核型分析和染色体微阵列分析相比,全外显子测序的阳性率提高了一倍多。值得注意的是,染色体异常是胎儿死亡的主要原因(75%,9/12),而小变异在选择性流产病例中更为常见(68%,24/35),尤其是那些伴有中枢神经和骨骼异常的病例。在35例不确定病例(18%)中识别出了额外的候选变异,可能会进一步提高检测率。本研究强调了三联体全外显子测序在诊断妊娠丢失遗传原因方面的价值。将其作为一线检测方法可显著增强我们对胎儿死亡和异常的理解,从而有助于未来进行明智的妊娠管理。