GATA2 and hyperinsulinemic hypoglycemia, familial, 4: For GATA2 deficiency, germline mutation involves truncating mutations, missense mutations within zinc finger 2, and noncoding variants in the + 9.5-kb regulatory region of GATA2. Most adolescent individuals with monosomy 7 MDS carry an underlying GATA2 deficiency [35]; thus, genetic testing for GATA2 may be necessary and is recommended in the Nordic guidelines [7].