This gene is similar to the protein kinase, X-linked gene in the pseudoautosomal region of the X chromosome. The gene is classified as a transcribed pseudogene because it has lost a coding exon that results in all transcripts being candidates for nonsense-mediated decay (NMD) and unlikely to express a protein. Abnormal recombination between this gene and a related gene on chromosome X is a frequent cause of XX males and XY females.Schiebel K., Hum. Mol. Genet. 6:1985-1989(1997).The MGC Project Team; Genome Res. 14:2121-2127(2004).Schiebel K., Cytogenet. Cell Genet. 76:49-52(1997).