Cyclin A1 is essential for meiosis as shown by its essential role in mouse spermatogenesis, suggesting that changes in the gene may also alter male fertility in humans. In the present study, we performed a mutation screening of the cyclin A1 gene in order to investigate the possible association between the mutations of the gene and human impaired spermatogenesis using denaturing high performance liquid chromatography (DHPLC) in 347 infertile patients with azoospermia or severe oligozoospermia and 210 fertile controls. Four point mutations, c.321T>C, IVS3+32G>C, IVS5+38A>G and c.1158G>A, were identified, but no association of these with spermatogenesis impairment was detected, suggesting that these cyclin A1 gene mutations are unlikely a common genetic cause for impaired human spermatogenesis. [ABSTRACT FROM AUTHOR]