Abstract：
BACKGROUND: As one of the most common congenital abnormalities in male births, cryptorchidism has been found to have a polygenic aetiology according to previous studies of common variants. However, little is known about genetic predisposition of rare variants for cryptorchidism, since rare variants have larger effective size on diseases than common variants.
METHODS: In this study, a cohort of 115 Chinese probands with cryptorchidism was analysed using whole-genome sequencing, alongside 19 parental controls and 2136 unaffected men. Additionally, CRISPR-Cas9 editing of a conserved variant was performed in a mouse model, with MRI screening used to observe the phenotype.
RESULTS: In 30 of 115 patients (26.1%), we identified four novel genes (ARSH, DMD, MAGEA4 and SHROOM2) affecting at least five unrelated patients and four known genes (USP9Y, UBA1, BCORL1 and KDM6A) with the candidate rare pathogenic variants affecting at least two cases. Burden tests of rare variants revealed the genome-wide significances for newly identified genes (p<2.5×10-6) under the Bonferroni correction. Surprisingly, novel and known genes were mainly found on X chromosome (seven on X and one on Y) and all rare X-chromosomal segregating variants exhibited a maternal inheritance rather than de novo origin. CRISPR-Cas9 mouse modelling of a splice donor loss variant in DMD (NC_000023.11:g.32454661C>G), which resides in a conserved site across vertebrates, replicated bilateral cryptorchidism phenotypes, confirmed by MRI at 4 and 10 weeks. The movement tests further revealed symptoms of Duchenne muscular dystrophy (DMD) in transgenic mice.
CONCLUSIONS: Our results revealed the role of the DMD gene mutation in causing cryptorchidism. The results also suggest that maternal-X inheritance of pathogenic defects could have a predominant role in the development of cryptorchidism.
METHODS: In this study, a cohort of 115 Chinese probands with cryptorchidism was analysed using whole-genome sequencing, alongside 19 parental controls and 2136 unaffected men. Additionally, CRISPR-Cas9 editing of a conserved variant was performed in a mouse model, with MRI screening used to observe the phenotype.
RESULTS: In 30 of 115 patients (26.1%), we identified four novel genes (ARSH, DMD, MAGEA4 and SHROOM2) affecting at least five unrelated patients and four known genes (USP9Y, UBA1, BCORL1 and KDM6A) with the candidate rare pathogenic variants affecting at least two cases. Burden tests of rare variants revealed the genome-wide significances for newly identified genes (p<2.5×10-6) under the Bonferroni correction. Surprisingly, novel and known genes were mainly found on X chromosome (seven on X and one on Y) and all rare X-chromosomal segregating variants exhibited a maternal inheritance rather than de novo origin. CRISPR-Cas9 mouse modelling of a splice donor loss variant in DMD (NC_000023.11:g.32454661C>G), which resides in a conserved site across vertebrates, replicated bilateral cryptorchidism phenotypes, confirmed by MRI at 4 and 10 weeks. The movement tests further revealed symptoms of Duchenne muscular dystrophy (DMD) in transgenic mice.
CONCLUSIONS: Our results revealed the role of the DMD gene mutation in causing cryptorchidism. The results also suggest that maternal-X inheritance of pathogenic defects could have a predominant role in the development of cryptorchidism.
摘要：
背景：作为男性出生中最常见的先天性异常之一，根据先前对常见变异的研究，隐睾已被发现具有多基因病因。然而,对隐睾罕见变异的遗传易感性知之甚少，因为罕见变异对疾病的有效大小比普通变异更大。
方法：在本研究中，使用全基因组测序分析了115名患有隐睾的中国先证者，与19名父母控制和2136名未受影响的男性一起。此外,在小鼠模型中进行保守变体的CRISPR-Cas9编辑，用MRI筛查观察表型。
结果：115例患者中有30例（26.1%），我们鉴定了四个新基因(ARSH，DMD,MAGEA4和SHROOM2）影响至少五名无关患者和四个已知基因（USP9Y，UBA1，BCORL1和KDM6A）具有候选的罕见致病性变异，至少影响两个病例。罕见变异的负担测试揭示了在Bonferroni校正下新鉴定的基因（p<2.5×10-6）的全基因组意义。令人惊讶的是,新的和已知的基因主要在X染色体上发现（X上有七个，Y上有一个），并且所有罕见的X染色体分离变体都表现出母体遗传而不是从头起源。DMD中剪接供体丢失变体的CRISPR-Cas9小鼠建模（NC_000023.11：g.32454661C>G），它位于脊椎动物的保守部位，复制的双侧隐睾表型，在4周和10周时通过MRI证实。运动测试进一步揭示了转基因小鼠中Duchenne肌营养不良(DMD)的症状。
结论：我们的结果揭示了DMD基因突变在引起隐睾中的作用。结果还表明，致病性缺陷的母体X遗传可能在隐睾的发展中起主要作用。
方法：在本研究中，使用全基因组测序分析了115名患有隐睾的中国先证者，与19名父母控制和2136名未受影响的男性一起。此外,在小鼠模型中进行保守变体的CRISPR-Cas9编辑，用MRI筛查观察表型。
结果：115例患者中有30例（26.1%），我们鉴定了四个新基因(ARSH，DMD,MAGEA4和SHROOM2）影响至少五名无关患者和四个已知基因（USP9Y，UBA1，BCORL1和KDM6A）具有候选的罕见致病性变异，至少影响两个病例。罕见变异的负担测试揭示了在Bonferroni校正下新鉴定的基因（p<2.5×10-6）的全基因组意义。令人惊讶的是,新的和已知的基因主要在X染色体上发现（X上有七个，Y上有一个），并且所有罕见的X染色体分离变体都表现出母体遗传而不是从头起源。DMD中剪接供体丢失变体的CRISPR-Cas9小鼠建模（NC_000023.11：g.32454661C>G），它位于脊椎动物的保守部位，复制的双侧隐睾表型，在4周和10周时通过MRI证实。运动测试进一步揭示了转基因小鼠中Duchenne肌营养不良(DMD)的症状。
结论：我们的结果揭示了DMD基因突变在引起隐睾中的作用。结果还表明，致病性缺陷的母体X遗传可能在隐睾的发展中起主要作用。
