CATSPER2 and deafness: 86 Although both may cause infertility albeit withdifferential effects on semen quality, CATSPER1 isnon-syndromic, whereas CATSPER2 is syndromic(deafness-infertility syndrome).87 At a semen analysis level, menwith CATSPER1 mutations have oligozoospermia, reduced semenvolume, minor changes to sperm motility, and some effect on morphology, whereasmen with CATSPER2 mutations have oligozoospermia,asthenospermia, teratazoospermia, and reduced viability.87