Hypospadias, one of the most common congenital anomalies of male urogenital system, is a disease in sexual mal-differentiation, and its etiology is unclear.

• 尿道下裂是男性泌尿生殖系统最常见的先天性畸形之一，是一种原因不明的性别分化异常，主要表现为尿道外口异位，阴茎弯曲畸形，阴茎背侧包皮堆积等。