GATA2 Gene Sequencing
The GATA2 gene encodes a transcription factor protein, GATA2, which is expressed in hematopoietic stem cells. This protein contains two zinc finger domains that promote protein-protein and protein-DNA communication. GATA2 functions in the formation of early blood and lymphatic vessels.
Heterozygous mutations in GATA2 demonstrate considerable phenotypic heterogeneity and have been reported in association with Emberger syndrome (primary lymphedema and MDS/AML, with or without congenital deafness), immunodeficiency-21 (profound decrease or absence of monocytes, B lymphocytes, NK lymphocytes and dendritic cells with no effect on T cell numbers with resulting opportunistic infections, pulmonary alveolar proteinosis and hypoplastic bone marrow/aplastic anemia) as well as in familial MDS/AML. Spinner (2014) recently summarized clinical findings in 57 patients with GATA2 mutations. Neutropenia was identified in about one half at presentation. Pasquet et al. (2013) described 14 patients who initially presented with congenital neutropenia secondary to a heterozygous mutation in GATA2, and 10 of 14 patients progressed to MDS/AML over the course of study.GATA2 deficiency is highly variable; however, outcome in patients summarized by Spinner et al. (2014) was guarded and hematopoietic stem cell transplantation (HSCT) may be a consideration in patients with severe disease. Presentation may be delayed into adulthood and presymptomatic screening of at-risk relatives is recommended for appropriate disease management, prophylaxis and consideration of HSCT.
Confirmation of diagnosis in a patient with the following:
- Emberger syndrome (primary lymphedema with myelodysplastic syndrome)
- Familial myelodysplastic syndrome
- Dendritic cell, monocyte, B, and natural killer (NK) lymphoid deficiency
- Family member with previously identified GATA2 mutation
Testing is performed by Sanger sequencing of the entire coding regions and intron/exon boundaries of the GATA2 gene.
Unknown due to the phenotypic heterogeneity of this condition. In one study of 14 cases of WHIM-like syndrome with negative sequencing for ELANE, CXCR4, SBDS, and G6PC, sequence changes were identified in 5 probands (approximately 35%) (Pasquet et al. 2013)
The sensitivity of DNA sequencing is over 99% for the detection of nucleotide base changes, small deletions and insertions in the regions analyzed.
Mutations in regulatory regions or other untranslated regions are not detected by this test. Large deletions involving entire single exons or multiple exons, large insertions and other complex genetic events have been reported in many of these genes and will not be identified using this test methodology. Rare primer site variants may lead to erroneous results.
Bigley, V., M. Haniffa, et al. (2011). "The human syndrome of dendritic cell, monocyte, B and NK lymphoid deficiency." J Exp Med 208(2): 227-234.
Dickinson, R. E., H. Griffin, et al. (2011). "Exome sequencing identifies GATA-2 mutation as the cause of dendritic cell, monocyte, B and NK lymphoid deficiency." Blood 118(10): 2656-2658.
Hahn, C. N., C. E. Chong, et al. (2011). "Heritable GATA2 mutations associated with familial myelodysplastic syndrome and acute myeloid leukemia." Nat Genet 43(10): 1012-1017.
Hsu, A. P., E. P. Sampaio, et al. (2011). "Mutations in GATA2 are associated with the autosomal dominant and sporadic monocytopenia and mycobacterial infection (MonoMAC) syndrome." Blood 118(10): 2653-2655.
Mace, E. M., A. P. Hsu, et al. (2013). "Mutations in GATA2 cause human NK cell deficiency with specific loss of the CD56 (bright) subset." Blood 121(14): 2669-2677.
Mansour, S., F. Connell, et al. (2010). "Emberger syndrome-primary lymphedema with myelodysplasia: report of seven new cases." Am J Med Genet A 152A(9): 2287-2296.
Ostergaard, P., M. A. Simpson, et al. (2011). "Mutations in GATA2 cause primary lymphedema associated with a predisposition to acute myeloid leukemia (Emberger syndrome)." Nat Genet 43(10): 929-931.
Pasquet, M., C. Bellanne-Chantelot, et al. (2013). "High frequency of GATA2 mutations in patients with mild chronic neutropenia evolving to MonoMac syndrome, myelodysplasia, and acute myeloid leukemia." Blood 121(5): 822-829.
Spinner, M. A., L. A. Sanchez, et al. (2014). "GATA2 deficiency: a protean disorder of hematopoiesis, lymphatics, and immunity." Blood 123(6): 809-821.