CHEK2 and pure red-cell aplasia: Deleterious mutations in ATM and CHEK2 thus represent 0.8% (each) of the cases enrolled in this study, with the nonsense ATM mutation representing 2.2% of the cases fulfilling criteria for familial/hereditary PrCa (A group), which resembles the frequency of mutations found in BRCA2 in earlier studies [27,35].