Iguchi et al,1 and Ravel et al.2 have proposed that, in the heterozygous state, the c.102G→T and the c.-107G→C transversions in the protamine 1 gene (PRM1), could be causes of human male infertility. Deleterious mutations in one allele of the human PRM1 gene are reasonably expected to have a dominant negative effect on male fertility, because in the mouse, germ cells carrying one null Prm1 allele do not produce viable gametes.3 In human PRM1 studies,1 2 however, several infertile men carried one of the two transversions, evoking the possibility of founder effects and therefore efficient transmission. To explore this apparent paradox, we screened 1195 infertile and control men for these two transversions, and conclude that neither has a significant effect on male fertility.

Iguchi et al originally described the 102T variant in 3 heterozygotes out of 30 infertile men with a normal sperm count but with raised levels of abnormal spermatozoa: <4.4% normal forms and/or >27% with DNA fragmentation.1 This variant results in substitution of a conserved amino acid, and was not found in public databases or in 10 controls recruited locally.1 A contemporaneous study discovered 102T independently in one infertile man and one fertile control.4 A later study found it in one oligozoospermic man with …