Additionally, BRCA1 mutations are present in approximately 10–15% of cases, BRCA2 mutations in 6–8%, and BRCA1 promoter methylation in around 10%, with approximately 50% of cases demonstrating homologous recombination deficiency (HRD)13,14. The gene discussed is BRCA1; the disease is hypoparathyroidism-retardation-dysmorphism syndrome.