In this joumal, Miharu and coworkers (1994) recently published a study on numerical chromosome abnormalities in spermatozoa of fertile men and patients with unexplained infertility. In their painstaking analysis of 450580 spermatozoa, they did not detect significant differences in the disomy rates between the two study groups. The authors conclude that aneuploidy in sperm is not a major contributor to unexplained infertility.
Unexplained (idiopathic) male infertility is a perplexing problem both for the patient and his physician. Despite extensive clinical investigations, this unsatisfactory 'diagnosis' is assigned to one out of three to four men attending andrological clinics (Nieschlag and Behre 1992). Research into this problem should be a high priority and we appreciate the great care Miharu et al. (1994) have taken in performing their cytogenetic studies. However, the validity of their results and the conclusions drawn therefrom are compromised by shortcomings in their clinical documentation. We think that, in this respect, their report is paradigmatic for many studies examining male infertility from a primarily genetic point of view. Beyond directing attention to this prevalent problem in the genetic literature, we should like to put forward some suggestions for improvements.
A large number of genetic and non-genetic factors are now known to impair or totally ablate male fertility (Nieschlag and Behre 1992; Skakkebaek et al. 1994). Each individual case needs to be thoroughly analysed with respect to symptomatology, etiology and therapeutic options available (Nieschlag 1993). Standard approaches to the examination and laboratory investigation of the infertile male have been elaborated and published (Aitken 1992; D. Meschede (lYe) -J. Horst