RB1 and alpha thalassemia spectrum: The most frequently mutated gene is p53 (30%), followed by alpha thalassemia/mental retardation syndrome X-linked (ATRX) (25%), mediator complex subunit 12 (MED12) (20%), retinoblastoma protein (RB1), and breast cancer gene-2 (BRCA2) [7,33,34,35].