More than 20% of marriedcouples in Japan are affected by infertility and the malepartner is responsible in two-thirds of these cases (23).We undertook an extensive analysis of genetic polymorphismsin germ cell-specific genes and of the relationshipbetween gene polymorphisms and infertility (7-19).We found potential relationships between infertility inJapanese men and genetic polymorphisms or mutationsin PRM2, TP1, PGAM4, and SCOT-T (7, 8, 15, 19). The gene discussed is PGAM4; the disease is Infertility.