Alu sequence variants of the BPY2 gene in proven fertile and infertile men with Sertoli cell-only phenotype.
OBJECTIVE
The basic protein on Y chromosome, 2 gene (BPY2) is implicated in the spermatogenic process. Three copies (paralogs) of the BPY2 sequence lie in the AZFc region, within huge palindromic repeats consisting of Alu sequences located in 5' flanking regions. Our objective was to screen the single nucleotide variation of BPY2 gene paralogously.


METHODS
Mutation screening of the exons and 5' flanking region of the BPY2 genes was carried out by polymerase chain reaction (PCR) and sequencing in 106 infertile patients with a Sertoli cell-only (SCO) phenotype and in 126 fertile men.


RESULTS
No sequence variation was detected in any of the BPY2 exons. Paralogous A/A/A and mixed A/G genotypes are referred to the promoter of the gene. The G/G/G genotype (wild type) was observed at the rates of 89.6% (95/106) in the SCO subjects and 96.0% (121/126) in the proven-fertile subjects. The G/G/G plus mixed A/G paralogous variants and the A/A/A paralogous variant were detected in 96.2% (102/106) and 3.8% (4/106) of infertile patients with SCO, respectively. The G/G/G plus mixed A/G paralogous variants were detected in 100% (126/126) of the fertile controls, with no instances of the A/A/A phenotype, and this difference was statistically significant (P = 0.038, Fisher's exact test).


CONCLUSIONS
The A/A/A genotype may be associated with the SCO phenotype. The alteration of all three copies of BPY2 within the AZFc region on the Y chromosome may affect spermatogenic process.
Choi
Jin
J
Department of Integrated Cancer Therapy and Urology, Kanazawa University Graduate School, Kanazawa, Japan.
Koh
Eitetsu
E
Suzuki
Hiromi
H
Maeda
Yuji
Y
Yoshida
Atsumi
A
Namiki
Mikio
M
D006801:Humans; D007248:Infertility, Male / Q000235:genetics*; D008297:Male; D010641:Phenotype; D011506:Proteins / Q000235:genetics*; D012708:Sertoli Cells
C466623:BPY2 protein, human; D011506:Proteins