Spermatogenic failure-27 (SPGF27) is characterized by infertility due to multiple morphologic abnormalities of the sperm flagella (MMAF), a phenotype also designated as 'dysplasia of the fibrous sheath,' 'short tails,' or 'stump tails.' Spermatozoa in the ejaculate exhibit short, irregular, coiled, or absent flagella. Ultrastructural analysis shows loss of the central pair of microtubules, loss of the inner dynein arms, and peripheral doublet disorganization (Lores et al., 2018). For a discussion of the phenotypic and genetic heterogeneity of spermatogenic failure, see SPGF1 (258150).

Spermatogenic failure-34 (SPGF34) is characterized by multiple morphologic abnormalities of the flagella (MMAF), resulting in immotile spermatozoa and infertility. Irregular-caliber, short, and coiled flagella are primarily observed, as well as absent flagella, and abnormalities of the axoneme are also present (Martinez et al., 2018). For a general phenotypic description and a discussion of genetic heterogeneity of spermatogenic failure, see SPGF1 (258150).

Spermatogenic failure-35 (SPGF35) is characterized by multiple morphologic abnormalities of the flagella (MMAF), resulting in spermatozoa with severely impaired motility and infertility. Short, thickened, and coiled flagella are primarily observed, as well as absent flagella, and abnormalities of axonemal composition are also present (Shen et al., 2019).

Spermatogenic failure-43 (SPGF43) is characterized by infertility and spermatozoa lacking progressive motility due to multiple morphologic abnormalities of the flagella (MMAF), including short, absent, coiled, irregular-caliber, and/or bent flagella. Most flagella lack the central pair (9+0 configuration) on ultrastructural analysis (Liu et al., 2019; Sha et al., 2019; Liu et al., 2020). For a discussion of genetic heterogeneity of spermatogenic failure, see SPGF1 (258150).

Spermatogenic failure-51 (SPGF51) is characterized by male infertility due to severe asthenoteratozoospermia. Patients exhibit multiple morphologic abnormalities of the flagella (MMAF), including absent, short, bent, coiled, and irregular-caliber tails, resulting in severely reduced to absent motility. Abnormalities of the sperm head, base, and acrosome have also been observed (Martinez et al., 2020). For a discussion of genetic heterogeneity of spermatogenic failure, see SPGF1 (258150).

Spermatogenic failure-72 (SPGF72) is characterized by male infertility due to multiple morphologic abnormalities of the flagella (MMAF), including coiled, short, angulated, absent, and irregular-caliber flagella, resulting in lack of sperm motility (Ni et al., 2020). For a general phenotypic description and discussion of genetic heterogeneity of spermatogenic failure, see SPGF1 (258150).

X-linked spermatogenic failure-6 (SPGFX6) is characterized by male infertility due to asthenoteratozoospermia. Patient spermatozoa show reduced progressive motility, and multiple morphologic abnormalities of the flagella (MMAF) are observed, primarily short and coiled flagella. Pregnancy can be achieved by intracytoplasmic sperm injection (ICSI) (Liu et al., 2021). For a general phenotypic description and discussion of genetic heterogeneity of spermatogenic failure, see SPGF1 (258150).