A novel mutation in FK506 binding protein-like (FKBPL) causes male infertility

To perform a mutation analysis of FK506 binding protein-like (FKBPL) in patients with azoospermia.

DNA samples were isolated from the peripheral blood of 30 azoospermic male patients with normal 46 XY karyotype and 10 healthy controls. Multiplex polymerase chain reaction assays were used to evaluate Y microdeletions, and the patients without deletions were further analyzed. Sanger sequencing was used for mutation analysis.

A heterozygous adenine to guanine substitution was observed at position c.28 (c.28A>G) (one patient), guanine to adenine substitution at c.90 (c.90G>A) (three patients), and a novel insertion mutation of TCTCATAAGTCT at c. 229_240dup (two patients), all in FKBPL exon 2. Furthermore, four different benign variants were observed in the same gene.

Our study supports the literature on the etiologic effects of changes on autosomal chromosomes and highlights the importance of molecular analysis of all known and unknown genes that could be involved in male sexual development and function.