Colorectal cancer (CRC) with HR deficiency (HRD), developed via biallelic somatic variants of HR-related genes, including BRCA1/2, were more frequent in MSI-H/dMMR than in MMS/pMMR, suggesting a significant association between alterations in the HRD pathway and dMMR [41, 42]. The gene discussed is BRCA1; the disease is hypoparathyroidism-retardation-dysmorphism syndrome.