Inheritance of infertility

Abstract

Genetic causes of infertility in men and women occur in the sex chromosomes as well as autosomes. There are several possible modes of transmission namely, numerical chromosomal abnormalities, structural chromosomal abnormalities, Mendelian traits, multifactorial traits, advanced parental age, as well as mitochondrial and cytoplasmic factors. Idiopathic male infertility is now ascribed to deletions in the Y chromosome and the azoospermic factors. Congenital bilateral or unilateral absence of the vas deferens (CBAVD) causes infertility and can occur in patients with cystic fibrosis as well as patients with renal abnormalities. In the management of male infertility, the modality that is currently widely used is intracytoplasmic sperm injection (ICSI). However, there are some accompanying concerns regarding the genetic risks of ICSI, such an increased incidence of sex chromosome aneuploidy. Polycystic ovary syndrome (PCOS), premature ovarian failure (POF) and endometriosis are known conditions causing infertility in the female. Recent evidence shows a significant genetic association with these conditions. The management of subfertility or infertility caused by these conditions is diverse and beyond the scope of this paper. Patients with idiopathic infertility, family history of infertility, with a known congenital abnormality, in a consanguineous marriage, as well as advanced parental age should be offered genetic counselling, physical evaluation of dysmorphology as well as cytogenic studies as part of management of infertility. Inheritance of infertility is a complex subject that continues to unfold with diverse management options. A multidisciplinary team in centres with a reproductive biology unit should manage such couples.