FSHB and Infertility: Of particular interest were two mutations in FSHB (Cys51Gly and Cys82Arg) that are involved in forming the cysteine-knot-like structure of the protein (again comparable to our patient mutation) and also lead to FSH-deficiency with female sexual infantilism and infertility in female and azoopermia but normal masculinization in male [47].