High-grade serous carcinoma (HGSC) accounts for ∼70% of EOC cases; 13% of HGSC patients have a germline mutation in BRCA1/2, and ∼50% have a somatic homologous recombination deficiency (HRD) [7]. This evidence concerns the gene BRCA1 and hypoparathyroidism-retardation-dysmorphism syndrome.