Vegni-Talluri et al. (1977) observed acrosome malformations of spermatids and spermatozoa in the testes of 2 infertile males who were investigated by light and electron microscopy. The first visible abnormality appeared at early spermatid stages. Defective differentiation of the acrosome granule in spermatids appeared to be responsible for the malformation of mature spermatozoa. The fact that about half the early spermatids lacked the acrosome granule suggested that the original cause is genetic and that the gene is expressed in the haploid phase. The gene might be X-linked or autosomal. The authors referred to comparable abnormalities of the acrosome observed in bulls and boars and thought to have a mendelian basis. Complete lack of the acrosome during spermiogenesis, resulting in round-headed spermatozoa incapable of fertilization, has been observed in man and has been thought to have a primary genetic basis. Furthermore, the authors drew analogies to abnormalities of spermatozoa related to the T-locus of the mouse. Abnormalities of spermiogenesis in mammals were reviewed by Bishop (1972). Kullander and Rausing (1975) observed only round-headed spermatozoa in 2 infertile brothers and suggested that homozygosity for an autosomal gene defect underlies this phenotype. In Friesian bulls, a characteristic defect of the acrosome ('knobbed' spermatozoa) associated with sterility appears to be autosomal recessive.
Florke-Gerloff et al. (1983) showed that the acrosomal membrane proteins are first detectable in early spermatids. (The acrosome is a caplike compartment in the apical part of the sperm head. It is a lysosome-like organelle derived from the Golgi apparatus. In the fertilization process, fusion of the sperm plasma membrane and outer acrosomal membrane (OAM) occurs with discharge of the acrosomal endosol.) Florke-Gerloff et al. (1983) found that the round-headed spermatozoa of an infertile patient with globozoospermia lacked the constituting components of the outer acrosomal membrane as well as the intraacrosomal acrosin system (see 102480). Nistal et al. (1978) observed 2 infertile brothers with round-headed spermatozoa. Florke-Gerloff et al. (1984) also found 2 affected brothers and studied their father as well. Whereas the brothers, like other reported cases, had all round-headed spermatozoa, the father had more than 94% normally shaped sperm. Theirs was the first study to quantitate the abnormality; in 9 infertile men the proportion of round-headed sperm varied from 14 to 71%. They showed that the round-headed spermatozoa lacked both acrosin and OAM, as indicated by immunofluorescent and immunoperoxidase staining techniques and confirmed by the gelatinolysis test. The normally shaped sperm of 6 of the 9 men were positive for acrosin and OAM. In the father of the affected brothers, only 10% of the normally shaped spermatozoa were acrosin positive and only 30% were positive for OAM. Florke-Gerloff et al. (1984) suggested that the round-headed spermatozoa syndrome is polygenic in its inheritance.
SEE ALSO
Victor A. McKusick : 6/16/1986
carol : 4/6/1994
mimadm : 3/11/1994
supermim : 3/16/1992
supermim : 3/20/1990
ddp : 10/26/1989
carol : 5/5/1989