Abstract
GATA2 deficiency syndrome is an autosomal dominant disorder caused by germline mutations in the GATA2 gene, which encodes a transcription factor with two zinc fingers that is essential for hematopoiesis. There are four types of these GATA2 mutations: truncating mutations proximal to the C-finger, C-finger missense mutations, noncoding mutations within an intron, and mutations resulting in aberrant mRNA splicing. Here, we report a novel GATA2 mutation that defines a new class of germline mutation: an in-frame insertion mutation that increases the separation of the two zinc fingers through the addition of nine amino acids. By several functional tests, this mutation was shown to be defective, establishing it as a pathogenic mutation and a new type of germline GATA2 mutation.