chr17-43067614-T-G
Variant summary
Our verdict is Uncertain significance. The variant received 1 ACMG points: 2P and 1B. PM1BP6
The NM_007294.4(BRCA1):c.5068A>C(p.Lys1690Gln) variant causes a missense change. The variant allele was found at a frequency of 0.000013 in 1,610,158 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. K1690N) has been classified as Uncertain significance.
Frequency
Consequence
NM_007294.4 missense
Scores
Clinical Significance
Conservation
Publications
- breast-ovarian cancer, familial, susceptibility to, 1Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, ClinGen, Labcorp Genetics (formerly Invitae), Genomics England PanelApp
- Fanconi anemia, complementation group SInheritance: AR Classification: DEFINITIVE, STRONG, MODERATE, LIMITED Submitted by: G2P, Labcorp Genetics (formerly Invitae), ClinGen, Ambry Genetics
- pancreatic cancer, susceptibility to, 4Inheritance: AD Classification: MODERATE Submitted by: Genomics England PanelApp
- hereditary breast ovarian cancer syndromeInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- Fanconi anemiaInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
Genome browser will be placed here
ACMG classification
Our verdict: Uncertain_significance. The variant received 1 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000197 AC: 3AN: 152188Hom.: 0 Cov.: 30 show subpopulations
GnomAD2 exomes AF: 0.0000318 AC: 8AN: 251360 AF XY: 0.0000442 show subpopulations
GnomAD4 exome AF: 0.0000123 AC: 18AN: 1457970Hom.: 0 Cov.: 30 AF XY: 0.0000124 AC XY: 9AN XY: 725550 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000197 AC: 3AN: 152188Hom.: 0 Cov.: 30 AF XY: 0.0000269 AC XY: 2AN XY: 74358 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
not provided Uncertain:2Benign:1
Published functional studies are inconclusive: conflicting homology-directed repair ability, defective protein instability, but normal nuclear localization and classified as functional by a saturation genome editing survival assay (PMID: 26689913, 30209399, 30257991); Observed in multiple individuals with breast or other cancers (PMID: 15365993, 18006916, 26221963, 28111427, 28364669, 31825140, 35205313); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Also known as 5187A>C; This variant is associated with the following publications: (PMID: 24772314, 28111427, 15365993, 26689913, 28664449, 28364669, 18006916, 21147198, 27257965, 26221963, 22333603, 30257991, 30209399, 30702160, 31470354, 31825140, 32467295, 33087888, 32803532, 29263802, 35205313, 36243179, 34621001, 31131967, 25348405) -
- -
In the published literature, this variant has been reported in individuals with breast cancer (PMID: 15365993 (2004), 18006916 (2007), 29263802 (2016), 30287823 (2018), 33471991 (2021), see also LOVD (https://databases.lovd.nl/shared/variants/BRCA1), breast and/or ovarian cancer (PMID: 28364669 (2017), 35205313 (2022)), and in unaffected individuals (PMID: 30287823 (2018), 32467295 (2020), 33471991 (2021), see also LOVD (https://databases.lovd.nl/shared/variants/BRCA1)). The effect of this variant on protein function is conflicting. Two functional studies reported this variant was functionally normal in a homology-directed DNA repair assay (PMID: 26689913 (2015)), and a saturation genome editing assay (PMID: 30209399 (2018)). However, another functional study reported this variant was defective in homology-directed DNA repair and was mostly insoluble in an E.coli solubility assay (PMID: 30257991 (2018)). The frequency of this variant in the general population, 0.00045 (9/19948 chromosomes in East Asian subpopulation (Genome Aggregation Database, http://gnomad.broadinstitute.org)), is higher than would generally be expected for pathogenic variants in this gene. Analysis of this variant using bioinformatics tools for the prediction of the effect of amino acid changes on protein structure and function yielded conflicting predictions that this variant is benign or damaging. Based on the available information, we are unable to determine the clinical significance of this variant. -
Hereditary cancer-predisposing syndrome Uncertain:1Benign:2
- -
- -
This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -
not specified Uncertain:1Benign:1
- -
Variant summary: BRCA1 c.5068A>C (p.Lys1690Gln) results in a conservative amino acid change located in the BRCT domain of the encoded protein sequence. Three of five in-silico tools predict a benign effect of the variant on protein function. A recent report from the CAGI5 (fifth Critical Assessment of Genome Interpretation) challenge has classified this variant as likely benign in a prediction protocol that includes assessment of the impact of this variant on splicing and protein function using four sets of predictors (Cline_2019). The variant allele was found at a frequency of 3.2e-05 in 251460 control chromosomes, predominantly at a frequency of 0.00044 within the East Asian subpopulation in the gnomAD database. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.5068A>C, has been reported in the literature in individuals affected with breast and/or ovarian Cancer, predominantly of Asian origin (example, Ang_2007, Lang_2017, Li_2017, Lu_2015, Park_2017, Ryu_2017, Seo_2004, Wong_2016, Zhong_2016). These report(s) do not provide unequivocal conclusions about association of the variant with Hereditary Breast And Ovarian Cancer Syndrome. At-least one co-occurrence with another pathogenic variant(s) has been reported (BRCA2 c.9294C>G, p.Y3098X, Wong_2016), providing supporting evidence for a benign role. Multiple publications report experimental evidence evaluating an impact on protein function. These results showed no damaging effect of this variant on homology directed repair (example, Findlay_2018). Eight clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. Multiple laboratories reported the variant with conflicting assessments (likely benign, n=2; VUS, n=6). At-least two submitters have re-classified this variant as likely benign since its previous evaluation. Some submitters cite overlapping evidence utilized in the context of this evaluation. Based on the evidence outlined above, the variant was classified as likely benign. -
Hereditary breast ovarian cancer syndrome Uncertain:1Benign:1
- -
- -
Familial cancer of breast;C2676676:Breast-ovarian cancer, familial, susceptibility to, 1;C3280442:Pancreatic cancer, susceptibility to, 4;C4554406:Fanconi anemia, complementation group S Uncertain:1
- -
Breast neoplasm Uncertain:1
- -
Malignant tumor of breast Uncertain:1
The BRCA1 p.Lys1690Gln variant was identified in 11 of 23576 proband chromosomes (frequency: 0.0005) from Asian individuals or families with breast and/or ovarian cancer and was present in 12 of 22482 control chromosomes (frequency: 0.0005) from healthy individuals (Momozawa 2018, Bhaskaran 2019, Ang 2007). The variant was also identified in dbSNP (ID: rs397507239) as "With Pathogenic, Uncertain significance allele", however it is noted that there is an alternate variant resulting in a stop codon at this position to which the pathogenic classification likely refers, ClinVar (classified as uncertain significance by Ambry Genetics, GeneDx, Color, Invitae and 3 other submitters; and as likely benign by SCRP), LOVD 3.0 (4 entries), UMD-LSDB (1 entry). The variant was also identified by our laboratory in 1 individual with breast cancer. The variant was identified in control databases in 8 of 277098 chromosomes at a frequency of 0.00003 (Genome Aggregation Database Feb 27, 2017). The variant was observed in the following populations: East Asian in 8 of 18864 chromosomes (freq: 0.0004), while the variant was not observed in the African, Other, Latino, European Non-Finnish, Ashkenazi Jewish, European Finnish, and South Asian populations. In a homology-directed repair assay this variant was shown to have activity comparable to wild type, though insufficient data was available to determine if the finding was statistically significant (Lu 2015). Protein sequence analysis suggests that Lys1690 plays a role in conjugation with small ubiquitin-like modifiers (SUMO) within the BRCT domain though the authors acknowledge that the exact site of conjugation remains unclear (Vialter 2011). The p.Lys1690 residue is conserved in mammals and computational analyses (PolyPhen-2, SIFT, AlignGVGD, BLOSUM, MutationTaster) provide inconsistent predictions regarding the impact to the protein; this information is not very predictive of pathogenicity. The variant occurs outside of the splicing consensus sequence and 2 of 4 in silico or computational prediction software programs (SpliceSiteFinder, MaxEntScan, NNSPLICE, GeneSplicer) predict a greater than 10% difference in splicing; this is not very predictive of pathogenicity. In summary, based on the above information the clinical significance of this variant cannot be determined with certainty at this time. This variant is classified as a variant of uncertain significance. -
Breast-ovarian cancer, familial, susceptibility to, 1 Benign:1
- -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at