Identification of BRCA1 biallelic pathogenic variants in a Fanconi Anemia patient and the clinical implications of variant location

Fanconi anemia subtype S (FA-S) is an extremely rare, autosomal recessive disorder caused by biallelic pathogenic mutations in BRCA1 and is characterized by physical abnormalities, developmental delay, and increased chromosomal breakage. The rarity of FA-S is likely due to embryonic lethality and cases resulting in live birth may be the result of some level of retained functional BRCA1 protein.