目的 分析45，X/46，X，+mar男性患儿的临床及遗传学特征。方法 回顾分析2例确诊45，X/46，X，+mar 男性患儿的临床资料，并复习相关文献。结果 2例男性患儿，年龄分别为10岁7个月和3岁1个月，均有矮小表现，且伴 有性腺发育落后。例1合并精索静脉曲张，头颅磁共振成像示部分空蝶鞍，外周血染色体核型分析为45，X[31]/46，X， +mar[69]，二代测序检测提示Y染色体短臂SRY基因拷贝数重复，长臂USP9Y基因整体缺失。例2外周血染色体核型分 析也为45，X[ 5]/ 46，X，+mar[ 75 ]，全基因组CNV检测提示染色体核型为46，XY，Y染色体AZFb+AZFc区域完全缺失。 结论 矮小症患儿应密切关注其外生殖器的形态及功能，必要时进行遗传学分析。

Objective? To report clinical features and genetic analysis of two cases of 45, X/ 46, X, +mar male children. Methods? Two hospitalized children with short stature were analyzed. The medical history and clinical data were collected, and karyotype analysis of peripheral blood was performed. The second-generation sequencing of sexual development related genes was performed in case one, and the whole genome copy number variation sequencing was performed in case two. Relevant literature was reviewed. Results? Two male children, one was 10 years and 7 months old, and the other was 3 years and 1 month old. Physical examination showed short stature, and complicated with gonadal development delay. Case one also presented with varicocele and partial empty sella revealed by cranial MRI, the karyotype of peripheral blood was 45, X [ 31 ] / 46, X, +mar [ 69 ]. The secondgeneration sequencing showed that the copy number of SRY gene on the short arm of Y chromosome was repeated, and USP9Y gene at long arm was deleted. In case two, the karyotype of the peripheral blood was 45, X [ 5 ] / 46, X, +mar [ 75 ]. The whole genome copy number variation sequencing test showed that the karyotype of 46, XY, AZFb + AZFc region of Y chromosome was completely deleted. Conclusion? Children with short stature should be paid close attention to the morphology and function of their external genitalia. If necessary, karyotype analysis or genetic analysis should be performed to avoid misdiagnosis.