Our verdict is Uncertain significance. Variant got 3 ACMG points: 4P and 1B. PM2PM5BP4
The NM_007294.4(BRCA1):āc.4223A>Gā(p.Gln1408Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (ā ā ). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. Q1408H) has been classified as Likely pathogenic.
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 3 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;
PM5
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PM5 - Novel missense change at an amino acid residue where a different missense change determined to be pathogenic has been seen before
Other missense variant is known to change same aminoacid residue: Variant chr17-43082537-C-G is described in ClinVar as [Likely_pathogenic]. Clinvar id is 694279.Status of the report is criteria_provided_single_submitter, 1 stars.
BP4
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BP4 - Multiple lines of computational evidence suggest no impact on gene or gene product (conservation, evolutionary, splicing impact, etc.)
Computational evidence support a benign effect (MetaRNN=0.2928459).
Uncertain significance, criteria provided, single submitter
clinical testing
Ambry Genetics
Sep 01, 2023
The p.Q1408R variant (also known as c.4223A>G), located in coding exon 11 of the BRCA1 gene, results from an A to G substitution at nucleotide position 4223. The glutamine at codon 1408 is replaced by arginine, an amino acid with highly similar properties. This variant was not reported in population based cohorts in the following databases: Database of Single Nucleotide Polymorphisms (dbSNP), NHLBI Exome Sequencing Project (ESP), and 1000 Genomes Project. In the ESP, this variant was not observed in 6503 samples (13006 alleles) with coverage at this position. To date, this alteration has been detected with an allele frequency of approximately 0.0004% (greater than 225000 alleles tested) in our clinical cohort. This amino acid position is well conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. 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
Oct 31, 2022
Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt BRCA1 protein function. ClinVar contains an entry for this variant (Variation ID: 481440). This missense change has been observed in individual(s) with breast cancer (PMID: 30254663). This variant is not present in population databases (gnomAD no frequency). This sequence change replaces glutamine, which is neutral and polar, with arginine, which is basic and polar, at codon 1408 of the BRCA1 protein (p.Gln1408Arg). 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. -