探讨多种遗传学检测技术鉴别诊断尿道下裂患儿染色体核型的意义。

选择2022年10月由广州医科大学附属妇女儿童医疗中心儿童泌尿外科收治的1例尿道下裂患儿，抽取患儿及父母外周血，综合运用染色体核型分析、多色荧光原位杂交(M-FISH)技术、染色体微阵列分析(CMA)和Y染色体性别决定基因(SRY)检测等技术进行遗传学分析，明确患儿的染色体核型和性别。

患儿男性，6月龄，系第2胎，母亲因患妊娠高血压综合征于32周早产，出生身长48 cm，体重2.3 kg，生后即发现排尿时尿液从阴茎体腹侧排出，无尿频、尿痛。查体可见阴茎发育不良，包皮帽状堆积，尿道口开口于阴茎体根部，局部无红肿炎症表现，双侧阴囊可触及性腺样物。阴囊超声提示双侧睾丸及附睾未见明显异常。患儿母亲核型正常，父亲核型为45，X，？ psu dic(Y；15)(q11.23；p13)，患儿核型初步诊断为45，X，？psu dic(Y；15)(q11.23；p13)pat；患儿CMA提示Y染色体信号完整，未见缺失和重复；SRY基因检测结果提示SRY基因未见缺失和突变；M-FISH结果为45，X，dic(Y；15)(p11.3；p11.2).ish dic(Y；15)(wcp 1～22，wcp XY)。结合上述检查，判断患儿为Y染色体和15染色体平衡易位产生的双着丝粒染色体携带者，遗传自父亲，染色体核型最终诊断为45，X，dic(Y；15)(p11.3；p11.2)pat，明确患儿性别为男性。

染色体核型分析是尿道下裂患儿的重要检测手段，综合多种遗传学检测技术对结构重排染色体的鉴别诊断有重要意义，可减少误诊风险。

To explore the significance of multiple genetic detection techniques in the differential diagnosis of chromosome karyotype in a child with hypospadias.

The case information of a child with hypospadias from the Urinary Surgery of Women and Children′s Medical Center Affiliated to Guangzhou Medical University was collected. The peripheral bloods of the child and his parents were extracted, and chromosome karyotype analysis, multicolorfluorescence in situ hybridization (M-FISH) technique, chromosome microarray analysis (CMA) and sex-determining region on the Y chromosome (SRY) were used for genetic analysis to determine the chromosomal karyotypes and sex of the children.

The child was male, 6 months old, the second fetus. The mother was preterm at 32 weeks due to pregnancy hypertension syndrome. The birth height was 48 cm, the weight was 2.3 kg, and the urine was found to be discharged from the ventral side of the penis during urination immediately after birth, without frequent urination or painful urination. Physical examination showed poor penis development, cap shaped accumulation of foreskin, urethral meatus at the root of the penis body, no local inflammation, and bilateral gonad being touched in scrotum. The ultrasound of scrotum showed no obvious abnormality in both testis and epididymis. The karyotype of the baby′mother was normal. The karyotype of his father was 45, X, ? psu dic(Y; 15) (q11.23; p13), so the karyotype of the baby was preliminarily diagnosed with 45, X, ? psu dic(Y; 15)(q11.23; p13)pat. CMA and SRY indicated that the Y chromosome of the child showed no deletion and mutation of SRY gene. The result of M-FISH of the baby was 45, X, dic(Y; 15)(p11.3; p11.2).ish dic(Y; 15)(wcp 1-22, wcp XY). Combined with the above examinations, it could be determined that the child was a dicentric chromosome carrier caused by balanced translocation of Y chromosome and chromosome 15, which was inherited from his father. The karyotype of the child was finally diagnosed with 45, X, dic(Y; 15)(p11.3; p11.2)pat, and the gender of the child was male.

Karyotype analysis is an important examination for children with hypospadias. Combined use of multiple genetic techniques is of great significance for differential diagnosis of chromosomal structural rearrangement, which contributes to reduce misdiagnosis.