The GATA1 gene provides instructions for making a protein that attaches to specific regions of DNA and helps control the activity of many other genes. The GATA1 protein is involved in the specialization of immature blood cells. To function properly, these immature cells must differentiate into specific types of mature blood cells. By binding to DNA and interacting with other proteins, the GATA1 protein regulates the growth and division of immature red blood cells and platelet-precursor cells to facilitate their differentiation. Red blood cells help carry oxygen to various tissues throughout the body and platelets aid in blood clotting. The GATA1 protein is also important for the maturation of several types of white blood cells that help fight infection, including eosinophils, mast cells, and dendritic cells.
Somatic mutations in the GATA1 gene increase the risk of developing a disease of blood-forming cells called transient myeloproliferative disorder (TMD). These mutations usually occur during fetal development, and the increased risk only applies to people who are born with an extra copy of chromosome 21 in each of their cells, a condition known as trisomy 21 or Down syndrome.
Approximately 10 percent of people with Down syndrome develop TMD, usually at birth or soon after. TMD is characterized by the accumulation of immature megakaryocyte precursor cells in the blood, liver, and bone marrow. In most cases, TMD causes no signs or symptoms and disappears within three to four months. However, approximately 20 percent of infants with TMD will have serious complications such as an enlarged liver, a buildup of scar tissue in the liver, excess fluid accumulation in the body before birth, and heart failure. It is estimated that 20 to 30 percent of children with TMD will later develop a cancer of the blood-forming cells called acute megakaryoblastic leukemia (AMKL). It is unclear why somatic GATA1 gene mutations increase the risk of developing these bone marrow disorders in people with Down syndrome.
Methodology: Sequencing of entire coding region
Purpose: Confirmation of Clinical Diagnosis
Test Requisition: Sequencing Requisition
CPT Codes: 81479 Cost: $616.00
Turn-around-time: 5-6 weeks
1. Cabelof DC, Patel HV, Chen Q, van Remmen H, Matherly LH, Ge Y, Taub JW. (2009) "Mutational spectrum at GATA1 provides insights into mutagenesis and leukemogenesis in Down syndrome". Blood. 24;114(13):2753-63.
2. Kobayashi M, Yamamoto M.(2007) "Regulation of GATA1 gene expression". J Biochem. 142(1):1-10. Epub 2007 Jun 13. Review.