We report biallelic BRCA1 mutations c.181T > G (p.Cys61Gly) and c.5096G > A (p.Arg1699Gln) in a woman with breast cancer diagnosed at the age of 30 years.
The BRCA2 c.9104A>C, p.Tyr3035Ser (OR = 2.52; <i>P</i> = 0.04), and BRCA1 c.5096G>A, p.Arg1699Gln (OR = 4.29; <i>P</i> = 0.009) variant were associated with moderately increased risks of breast cancer among Europeans, whereas BRCA2 c.7522G>A, p.Gly2508Ser (OR = 2.68; <i>P</i> = 0.004), and c.8187G>T, p.Lys2729Asn (OR = 1.4; <i>P</i> = 0.004) were associated with moderate and low risks of breast cancer among Asians.
The BRCA2 c.9104A>C, p.Tyr3035Ser (OR = 2.52; <i>P</i> = 0.04), and BRCA1 c.5096G>A, p.Arg1699Gln (OR = 4.29; <i>P</i> = 0.009) variant were associated with moderately increased risks of breast cancer among Europeans, whereas BRCA2 c.7522G>A, p.Gly2508Ser (OR = 2.68; <i>P</i> = 0.004), and c.8187G>T, p.Lys2729Asn (OR = 1.4; <i>P</i> = 0.004) were associated with moderate and low risks of breast cancer among Asians.
Measures of genetic risk (report of family history, segregation) were assessed for 68 BRCA1 c.5096G>A p.Arg1699Gln (R1699Q) families recruited through family cancer clinics, comparing results with 34 families carrying the previously classified pathogenic BRCA1 c.5095C>T p.Arg1699Trp (R1699W) mutation at the same residue, and to 243 breast cancer families with no BRCA1 pathogenic mutation (BRCA-X).