Genes involved are unknown. Whether an increased dosage of gene products located at 1q12-qter or the breakpoint at chromosomal location of Yq12 is important in the pathogenesis of MDS remains to be elucidated. Furthermore, since juxtaposition of heterochromatin and euchromatin has been shown to affect gene function, this may contribute to the pathogenic mechanism underlying der(Y)t(Y;1) as the heterochromatin at Yq12 is involved in the translocation.