SMC1A belongs to the cohesin complex family of genes that encode protein subunits of the cohesion complex, which regulates chromosomal segregation. SMC1A has been reported to show somatic, missense mutations throughout the gene in less than 5% of cases of acute myeloid leukemia and less than 5% of chronic myeloid leukemia. Mutations of SMC1A are mostly mutually exclusive of mutations in other components of the cohesin complex. Mutations of SMC1A may be enriched in male patients since the gene is located on the X chromosome. Cohesin complex mutations are associated with an unfavorable prognosis in myelodysplastic syndrome, and are more frequently found in patients with high IPSS scores and secondary acute myeloid leukemia.