Analysis of Yq microdeletions in infertile males by PGR and DNA hybridization techniques

Defects in spermatogenesis have been found associated with deletions of dif ferent portions of Y chromosome long arm (Yq), suggesting the presence of t he azoospermia factor in the control of spermatogenesis. We studied 67 men with idiopathic azoospermia and severe oligozoospermia, cytogenetically nor mal, for the presence of microdeletions on Yq chromosome. By using polymera se chain reaction (PCR) and Southern blotting techniques we analysed the AZ Fa, AZFb and AZFc loci on Yq, where deletions have been associated with def ects in spermatogenesis. Deletions of a portion of the Y chromosome were de tected in five patients. Four of these patients shared deletions in distal Yq11 interval 6, including the DAZ gene, while one patient lacked loci in t he proximal Yq11. Testicular histology of two patients bearing distal Yq11 deletions showed two different spermatogenic defects including Sertoli cell -only (SCO) syndrome and maturation arrest, while the patient with microdel etions in the proximal Yq11 showed a SCO phenotype.