On round-headed human spermatozoa.

In an infertile man and his only, likewise infertile, brother the sperm contained only round-headed spermatozoa. Electron microscopic examination of embedded ejaculate revealed a malformation, viz. absence of acrosomes in all the spermatozoa with consequent lack of normal development of the heads of the spermatozoa. Acrosomeless spermatozoa were also found in the testicular tubuli. No disturbance of the endocrine functions could be demonstrated. The blood cells were of normal male karyotype. Investigation of meiosis, on the other hand, showed rudimentary second division. Two other unrelated infertile men showed the same isolated disturbance in their spermiogram. Treatment with chlomiphene had no effect on the structure of the spermatozoa or on the infertility. The rare disorder, which seems to be a special syndrome, the first hitherto distinguishable among the various types of teratospermia, and its probable background are discussed.