FKBP6 is a 327 amino acid protein that, like other PPIases, accelerate the folding of proteins. As a component in synaptonemal complexes, FKBP6 is involved in homologous chromosomes pairing and male infertility in mice. There has been some suggestion that FKBP6 may play a role in modifying the susceptibility to idiopathic spermatogenic impairment in humans. Ubiquitously expressed in all tissues, FKBP6 is present at highest levels in testis, liver, kidney, skeletal muscle and heart. The gene encoding FKBP6 maps within a region of human chromosome 7 that has been implicated in Williams-Beuren syndrome, a rare developmental disorder involving abnormalities of the cardiovascular and musculoskeletal systems. Hemizygous deletion of FKBP6 may contribute to hypercalcemia and growth delay in Williams-Beuren syndrome.