MonoMAC

MonoMAC syndrome is a rare autosomal dominant syndrome associated with: monocytopenia, B and NK cell lymphopenia; mycobacterial, viral, fungal, and bacterial opportunistic infections; and virus infection-induced cancers. The disorder often progresses to the development of myelodysplasia, myeloid leukemias, and other types of cancer. MonoMAC is a life-threatening and precancerous disorder.[1][2]

Inactivating mutations in one of the two parental GATA2 genes is responsible for the many diverse presentations of a genetic disorder that groups these presentations together into a single disease termed GATA2 deficiency. These autosomal dominant mutations are known or presumed to cause a reduction, i.e. a haploinsufficiency, in the cellular levels of the gene's product, GATA2. The GATA2 protein is a transcription factor critical for the embryonic development, maintenance, and functionality of blood-forming, lympathic-forming, and other tissue-forming stem cells. In consequence of these mutations, cellular levels of GATA2 are deficient and individuals develop over time hematological, immunological, lymphatic, and/or other disorders that may begin as apparently benign abnormalities but commonly progress to severe organ (e.g. lung) failure, enhanced susceptibility to opportunistic infections, virus infection-induced cancers, the myelodysplastic syndrome, and/or various types of leukemia. MonoMAC is a presentation of GATA2 deficiency that involves primarily signs and symptoms of immune deficiency that cause an extremely high susceptibility to infections and infection-induced benign and malignant tumors. In addition to this, however, MonoMAC-afflicted individuals often show one or more signs and symptoms of other GATA2 presentations.[3][4]

MonoMAC was first described by Vihn and colleagues in 2010 as an autosomal dominant familial disease.[5] One year later, Dickinson and colleagues discovered that the MonoMAC disorder in four individuals was associated with any one of four different mutations in the GATA2 gene.[6] Subsequent studies identified numerous other GATA2 gene mutations that are associated with the development of MonoMAC, showed that these mutations inactivated or were considered likely to inactivate one of two parental GATA2 genes, and found that essentially all individuals with MonoMAC had one of the mutations known or considered to inactivate GATA2.[3]