ABSTRACT
Infertility in the presence of a severe male factor such as oligoasthenoteratospermia or azoospermia may be of genetic origin. This means that either the number or the structure of the chromosomes may be aberrant, or a gene defect may be present. For two major reasons, genetic investigations are indicated in case of male infertility. One reason is to understand more about the possible causes of azoospermia or oligoasthenoteratospermia. Another reason is to be able to offer genetic counseling to the patient, his partner, and his family whenever indicated. The role of genetic counseling in the case of infertility has, of course, increased since the advent of assisted reproductive techniques (ART) in general, and certainly since the use of intracytoplasmic sperm injection (ICSI), offering the possibility to men with almost no spermatozoa to have children.1-3 In the clinic, genetic investigations are usually performed when the azooor oligospermia is part of a more complex disease or syndrome. Based on the available data today, a number of genetic tests should also be performed in the case of infertility in an otherwise healthy male. In the majority of such cases it will be sufficient to start with analysis of the karyotype in peripheral lymphocytes, search for the presence or absence of a Yq11 deletion on the long arm of the Y chromosome, and/or analysis of cystic fibrosis transmembrane conductance regulator (CFTR) genes in couples in whom the male partner has congenital bilateral absence of the vas deferens (CBAVD). More specific genetic investigations can be done if indicated.
