Screening for Y chromosome microdeletions in childhood: lack of evidence for a direct association with testicular maldescent.

The aim of the study was to investigate the hypothesis that Y chromosome microdeletions are directly implicated in testicular maldescent. Genomic DNA was extracted from the peripheral blood of 292 subjects. This population consisted of (i) 180 children with all phenotypes of isolated (non-syndromic) testicular maldescent from 174 index families, (ii) affected adult relatives available (n = 12) and (iii) 100 unrelated children with normal external genitalia (controls). The sequence-tagged site primer set and the conditions of conventional polymerase chain reaction amplification were based on the current laboratory guidelines for molecular diagnosis of Y chromosome microdeletions recommended by the European Academy of Andrology and the European Molecular Genetics Quality Network. Two multiplex reactions were designed to screen the regions of azoospermic factors a, b and c. Each multiplex reaction included adequate internal and external amplification controls. Amplification products were submitted to electrophoresis on 2% agarose gel impregnated with ethidium bromide dye solution for 80 volt-h and visualised under ultraviolet light. No microdeletions were detected in any subject. These results indicate that Y chromosome microdeletions are not directly implicated in the pathogenesis of testicular maldescent. Other factors should be investigated to potentially explain the genetic predisposition that seems to exist in at least a subgroup of these patients.