A new case of Yq microdeletion transmitted from a normal father to two infertile sons.

During the last few years, microdeletions of the long arm of the Y chromosome, involving loci AZFa, AZFb, and AZFc, have been identified as a major cause of infertility, leading to the disruption of genes involved in spermatogenesis. These microdeletions are usually de novo mutations, but in six cases transmission from fertile fathers to infertile sons has been reported. In four cases, the transmission occurred to a single son, and in one of these a widening of the deletion was shown. In the remaining two cases, the microdeletion was transmitted to multiple sons, resulting in different defects of spermatogenesis. 6 Here, we describe a third family with a Yq microdeletion transmitted by a father to his two infertile sons.