In the two remaining patients, we did not identify any bi-allelic deleterious variant in potential candidate genes, which were defined as follows: (1) other genes involved in acephalic spermatozoa syndrome, particularly in PMFBP1 and TSGA10 [17,18,19,20]; (2) genes previously described in a context of male infertility; or (3) genes with a predominant testicular expression or restricted expression in the testes. This evidence concerns the gene PMFBP1 and spermatogenic failure 16.