New molecular diagnostic kit to assess Y-chromosome deletions in the Japanese population.
OBJECTIVE
Deletions in the azoospermia factor regions are the most common known molecular genetic cause of human male infertility involving spermatogenetic failure. Testing for these deletions in Japanese DNA samples using conventional sequence-tagged site probes occasionally lead to considerable non-specific or faint products in the Japanese population. The aim of the present study was to evaluate the sensitivity and specificity of a newly developed kit for the detection of azoospermia factor microdeletions in the Japanese population.


METHODS
Sequence-tagged site probes were reselected and the Luminex suspension array assay was carried out. Validation was retrospectively carried out with 2014 DNA sequences with known microdeletions, which were divided into four categories.


RESULTS
Category 1 deletions that corresponded to the conventional classification of azoospermia factor deletion were present in 83 men (4.2%), which can result in intrachromosomal homologous recombination. Kit data confirmed the presence of deletions of this type in DNA sequences known to harbor the azoospermia factor deletions. Category 2 deletions involved cytogenetic abnormalities in 28 men (1.4%), whereas category 3 deletions in 759 men (37.7%) were atypical classifications including the gr/gr deletion. As these deletions are thought to be a result of palindromic units and non-homologous recombination, these microdeletions might impact in the interpretation of some clinical findings. The rest of the 1145 cases (56.8%) were assigned to category 4 as normal variants (polymorphism/no deletion).


CONCLUSIONS
The present findings show that this new kit offers good sensitivity and specificity with the advantage of saving in terms of cost and time.
Departments of Integrative Cancer Therapy and Urology, Kanazawa University Graduate School of Medical Science, Kanazawa, Ishikawa, Japan.
Masashi
M
Iijima
Eitetsu
E
Koh
Kouji
K
Izumi
Masaki
M
Taya
Yuji
Y
Maeda
Kouichi
K
Kyono
Atsumi
A
Yoshida
Mikio
M
Namiki
D000328:Adult; D000368:Aged; D044466:Asian People; D002872:Chromosome Deletion; D041322:Chromosomes, Human, Y; D006801:Humans; D007248:Infertility, Male; D008297:Male; D008875:Middle Aged; D025202:Molecular Diagnostic Techniques; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D012729:Sex Chromosome Aberrations; D058533:Sex Chromosome Disorders of Sex Development / Q000175:diagnosis*; D055815:Young Adult
Y chromosome; azoospermia factor; detection kit; male infertility; microdeletion