Homozygous loss of function BRCA1 variant causing a Fanconi-anemia-like phenotype, a clinical report and review of previous patients

Eur J Med Genet. 2018 Mar;61(3):130-133. doi: 10.1016/j.ejmg.2017.11.003. Epub 2017 Nov 10.

Abstract

Background: Fanconi Anemia (FA) is a rare and heterogeneous genetic syndrome. It is associated with short stature, bone marrow failure, high predisposition to cancer, microcephaly and congenital malformation. Many genes have been associated with FA. Previously, two adult patients with biallelic pathogenic variant in Breast Cancer 1 gene (BRCA1) had been identified in Fanconi Anemia-like condition.

Clinical report: The proband was a 2.5 year-old girl with severe short stature, microcephaly, neurodevelopmental delay, congenital heart disease and dysmorphic features. Her parents were third degree cousins. Routine screening tests for short stature was normal.

Methods: We conducted whole exome sequencing (WES) of the proband and used an analysis pipeline to identify rare nonsynonymous genetic variants that cause short stature.

Results: We identified a homozygous loss-of-function BRCA1 mutation (c.2709T > A; p. Cys903*), which promotes the loss of critical domains of the protein. Cytogenetic study with DEB showed an increased chromosomal breakage. We screened heterozygous parents of the index case for cancer and we detected, in her mother, a metastatic adenocarcinoma in an axillar lymph node with probable primary site in the breast.

Conclusion: It is possible to consolidate the FA-like phenotype associated with biallelic loss-of-function BRCA1, characterized by microcephaly, short stature, developmental delay, dysmorphic face features and cancer predisposition. In our case, the WES allowed to establish the genetic cause of short stature in the context of a chromosome instability syndrome. An identification of BRCA1 mutations in our patient allowed precise genetic counseling and also triggered cancer screening for the patient and her family members.

Keywords: BRCA1; FANC genes; FANCA genes; Fanconi anemia; Genomic instability.

Publication types

  • Case Reports
  • Review

MeSH terms

  • BRCA1 Protein / genetics*
  • Child, Preschool
  • Fanconi Anemia / genetics*
  • Fanconi Anemia / pathology*
  • Female
  • Genetic Predisposition to Disease*
  • Genotype
  • Homozygote*
  • Humans
  • Male
  • Mutation*
  • Pedigree
  • Phenotype

Substances

  • BRCA1 Protein
  • BRCA1 protein, human