Efficacy of MLPA for detection of Y-chromosome microdeletions in infertile Brazilian patients.

Abstract

Worldwide publications follow the gold standard method-the polymerase chain reaction (PCR)-for detecting Y-chromosome microdeletions; however, markers are frequently variable between the studies. Can we detect the deletions by another molecular method with more genomic coverage? The Y chromosome harbors several different genes responsible for testicular development and spermatogenesis, and its repetitive conformation predisposes it to complex rearrangements that have clinical impact. Our aim was to evaluate a molecular diagnostic method, the Multiplex Ligand Probe-dependent Amplification (MLPA), which is also a valuable ancillary method for the identification of deletions, duplications, and rearrangements in a single and faster reaction, leading to a better comprehension of patients' phenotypes, and should be considered a useful tool for detection of Y chromosome deletions. This is a study of diagnostic accuracy (transversal prospective study) conducted to investigate Y-chromosome deletions in 84 individuals through PCR and MLPA methods. Forty-three infertile men (azoospermic and oligozoospermic) and 41 controls (40 fertile men and 1 normal karyotyped woman) were analyzed by PCR and MLPA techniques. We diagnosed seven (7) deletions (16.2%) by PCR and 9 with MLPA (21%). In addition, we found five (5) duplications and a suggestive mosaic. Our results demonstrate that MLPA technique is valuable in the investigation of microdeletions and microduplications. Besides deletions, duplications can cause instability of chromosome genes, possibly leading to infertility. Both studied techniques provide an advantageous diagnostic strategy, thus enabling a better genetic counseling.