RBMX2 is a 322 amino acid member of the IST3 family that contains one RRM (RNA recognition motif) domain. The RBMX2 gene is intronless, conserved in chimpanzee, dog, cow, mouse, rat, zebrafish, fruit fly, mosquito, C.elegans, S.pombe, S.cerevisiae, K.lactis, E.gossypii, M.grisea, N.crassa, A.thaliana, rice and P.falciparum, and maps to human chromosome Xq25. The X and Y chromosomes are the human sex chromosomes. Chromosome X consists of about 153 million base pairs and nearly 1,000 genes. The combination of an X and Y chromosome lead to normal male development while two copies of X lead to normal female development. More than one copy of the X chromosome with a Y chromosome causes Klinefelter's syndrome. A single copy of X alone leads to Turner's syndrome. More than 2 copies of the X chromosome, in the absence of a Y chromosome, is known as Triple X syndrome. Color blindness, hemophilia, and Duchenne muscular dystrophy are well known X chromosome-linked conditions that affect males more frequently as males carry a single X chromosome.