A case report of biallelic CHEK2 heterozygous variant presenting with breast cancer

Abstract Pathogenic germline variants in the CHEK2 gene have been shown to cause a moderate increased risk of breast cancer. Here, we present a striking CHEK2 family with a biallelic carrier of two frameshift pathogenic variants, to draw attention and to encourage a comprehensive genetic and cancer risk education for biallelic carriers of CHEK2 pathogenic variants.