XKRY Background Information XKRY (Kell blood group complex subunit-related, Y-linked), also known as testis-specific XK-related protein Y-linked, is a 159 amino acid protein belonging to the XK family. The gene that encodes XKRY is present as two identical copies within a palindromic and nonrecombining portion of the Y chromosome. The more centromeric copy of the XKRY gene is designated XKRY and the more telomeric copy is designated XKRY2. Localized to the plasma membrane, both XKRY and XKRY2 are expressed specifically in testis. XKRY and XKRY2 are similar to XK (X-linked Kell blood group precursor), a putative membrane transport protein that is associated with McLeod syndrome, an X-linked, recessive disorder characterized by abnormalities in the neuromuscular and hematopoietic systems.
