BRCA2 and Friedreich ataxia: Inheritance of two abnormal copies of BRCA1 or BRCA2 causes FA, an inherited bone marrow failure (BMF) syndrome characterized by increased sensitivity to DNA crosslinking agents, BMF, and a 785‐fold increased risk of developing hematologic malignancies.4, 5, 6, 7, 8 In contrast, inheriting one abnormal copy of BRCA1 or BRCA2 is more common, affecting 1 in 300 to 500 women in the general population,9 but the effect of a single mutation on bone marrow function is unclear.