Spermatogenic failure-40 (SPGF40) is characterized by multiple morphologic abnormalities of the flagella (MMAF), including absent, short, bent, coiled, and irregular-caliber tails, resulting in severely reduced to absent motility. Patient spermatozoa may also show morphologic defects of the sperm head, with acrosomal hypoplasia or aplasia (Wang et al., 2019; Li et al., 2020).
For a discussion of genetic heterogeneity of spermatogenic failure, see SPGF1 (258150). [from
OMIM]