Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2PM4
The NM_007294.4(BRCA1):c.2155_2163del(p.Lys719_Phe721del) variant causes a inframe deletion change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. K719K) has been classified as Likely benign.
BRCA1 (HGNC:1100): (BRCA1 DNA repair associated) This gene encodes a 190 kD nuclear phosphoprotein that plays a role in maintaining genomic stability, and it also acts as a tumor suppressor. The BRCA1 gene contains 22 exons spanning about 110 kb of DNA. The encoded protein combines with other tumor suppressors, DNA damage sensors, and signal transducers to form a large multi-subunit protein complex known as the BRCA1-associated genome surveillance complex (BASC). This gene product associates with RNA polymerase II, and through the C-terminal domain, also interacts with histone deacetylase complexes. This protein thus plays a role in transcription, DNA repair of double-stranded breaks, and recombination. Mutations in this gene are responsible for approximately 40% of inherited breast cancers and more than 80% of inherited breast and ovarian cancers. Alternative splicing plays a role in modulating the subcellular localization and physiological function of this gene. Many alternatively spliced transcript variants, some of which are disease-associated mutations, have been described for this gene, but the full-length natures of only some of these variants has been described. A related pseudogene, which is also located on chromosome 17, has been identified. [provided by RefSeq, May 2020]
Verdict is Uncertain_significance. Variant got 4 ACMG points.
PM2
?
PM2 - Absent from controls (or at extremely low frequency if recessive) in Exome Sequencing Project, 1000 Genomes Project, or Exome Aggregation Consortium
Very rare variant in population databases, with high coverage;
PM4
?
PM4 - Protein length changes as a result of in-frame deletions/insertions in a nonrepeat region or stop-loss variants
Nonframeshift variant in NON repetitive region in NM_007294.4.
Uncertain significance, criteria provided, single submitter
clinical testing
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Oct 03, 2016
Variant summary: The BRCA1 c.2155_2163delAAAGAATTT (p.Lys719_Phe721del) variant involves the deletion of 3 consecutive non-conserved amino acids that are not within a known functional domain. One in silico tool predicts a benign outcome for this variant. This variant was absent in 121246 control chromosomes. In addition, multiple clinical diagnostic laboratories/reputable databases classified this variant as uncertain significance. The variant of interest has not, to our knowledge, been reported in affected individuals via publications and/or reputable databases/clinical diagnostic laboratories; nor evaluated for functional impact by in vivo/vitro studies. Because of the absence of clinical information and the lack of functional studies, the variant is classified as a variant of uncertain significance (VUS) until additional information becomes available. -
Uncertain significance, criteria provided, single submitter
clinical testing
Ambry Genetics
Oct 05, 2020
The c.2155_2163delAAAGAATTT variant (also known as p.K719_F721del) is located in coding exon 9 of the BRCA1 gene. This variant results from an in-frame AAAGAATTT deletion at nucleotide positions 2155 to 2163. This results in the in-frame deletion of three amino acid residues at codons 719 to 721. This amino acid region is poorly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis (Choi Y et al. PLoS ONE. 2012; 7(10):e46688). Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -
Hereditary breast ovarian cancer syndrome Uncertain:1
Uncertain significance, criteria provided, single submitter
clinical testing
Invitae
Aug 29, 2022
ClinVar contains an entry for this variant (Variation ID: 216873). In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. Experimental studies and prediction algorithms are not available or were not evaluated, and the functional significance of this variant is currently unknown. This variant has not been reported in the literature in individuals affected with BRCA1-related conditions. This variant is not present in population databases (gnomAD no frequency). This variant, c.2155_2163del, results in the deletion of 3 amino acid(s) of the BRCA1 protein (p.Lys719_Phe721del), but otherwise preserves the integrity of the reading frame. -