Hypospadias is one of the most common congenital malformations among children. Both gene mutations and environmental factors are thought to be involved in the development of hypospadias. The mastermind-like domain-containing 1 gene (MAMLD1, formerly CXorf6) is a new candidate gene and its mutation has been shown in some cases of hypospadias. Here, by direct sequencing of PCR products, we assessed and found mutations that occur in 220 sporadic cases of hypospadias. The mutations p.N589S (c.1766A>G) was found at a significantly higher rate among patients with hypospadias.