ABSTRACT

Infertility associated with a severe male factor such as oligo-astheno-teratozoospermia (OAT) 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. Two major reasons are indicated for genetic investigations in case of male infertility. One reason is to understand more about the possible causes of azoospermia or OAT. 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 case of infertility has increased since the advent of assisted reproduction technology (ART) in general, and certainly since the introduction of intracytoplasmic sperm injection (ICSI), offering the possibility to have children to men with almost no spermatozoa (1–3). In the clinic, genetic investigations are usually performed when the azoospermia or oligozoospermia 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 case of infertility in an otherwise healthy male. In the majority of such cases it will be sufficient to start with the analysis of the karyotype in peripheral lymphocytes, a search for the presence of a Yq11 deletion on the long arm of the Y chromosome, and/or an analysis of the CFTR gene in couples in which the male partner has congenital bilateral absence of the vas deferens (CBAVD). More specific genetic investigations can be done if indicated.