17-43063909-C-G
Variant summary
Our verdict is Likely benign. Variant got -4 ACMG points: 5P and 9B. PM1PM5PP3BP4BP6_Very_Strong
The NM_007294.4(BRCA1):c.5117G>C(p.Gly1706Ala) variant causes a missense change. The variant allele was found at a frequency of 0.0000465 in 1,614,060 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Benign (★★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G1706E) has been classified as Pathogenic.
Frequency
Consequence
NM_007294.4 missense
Scores
Clinical Significance
Conservation
Genome browser will be placed here
ACMG classification
Verdict is Likely_benign. Variant got -4 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000657 AC: 10AN: 152136Hom.: 0 Cov.: 32
GnomAD3 exomes AF: 0.0000477 AC: 12AN: 251342Hom.: 0 AF XY: 0.0000515 AC XY: 7AN XY: 135856
GnomAD4 exome AF: 0.0000445 AC: 65AN: 1461806Hom.: 0 Cov.: 31 AF XY: 0.0000385 AC XY: 28AN XY: 727204
GnomAD4 genome AF: 0.0000657 AC: 10AN: 152254Hom.: 0 Cov.: 32 AF XY: 0.000107 AC XY: 8AN XY: 74446
ClinVar
Submissions by phenotype
Breast-ovarian cancer, familial, susceptibility to, 1 Uncertain:1Benign:8Other:1
- -
- -
- -
- -
- -
- -
IARC class based on posterior probability from multifactorial likelihood analysis, thresholds for class as per Plon et al. 2008 (PMID: 18951446). Class 1 based on posterior probability = 0.0000495 -
- -
- -
- -
not specified Benign:5
- -
- -
- -
- -
- -
not provided Benign:3
- -
Variant Summary: The BRCA1 c.5117G>C variant involves the alteration of a conserved nucleotide, resulting in an amino acid change from a Gly to an Ala at codon 1706. G1706 is a highly conserved residue located at the interface between the two BRCT domains, which forms the binding pocket for the peptide and functional studies have shown G1706A may be mildly destablizing (Lee_CR_2010); however, this finding was in contrast to Lovelock et al 2006, showing no change in stability. Regardless, the implications of this possible reduction in protein stability in cancer are not known. 4/5 in-silico tools predict a pathogenic outcome. Contrary to in silico and the conflicting stability assay results, multiple other functional assays from independent labs show the variant to have similar activity compared to WT, including, subcellular localization, transcriptional transactivation, centrosome amplification, binding activity, as well as splicing/transcription analysis via patient mRNA (Lovelock_2006, Campos_2003, Lee_CR_2010).The variant was observed in the large and broad cohorts of the ExAC project at an allele frequency of 0.004% which does not exceed the maximal expected allele frequency for a pathogenic variant in BRCA1 (0.10%). The variant has been reported in the literature in affected individuals, without strong evidence for causality (i.e. co-segregation with disease). The variant has been reported in databases and publications to co-occur in patients with pathogenic variants including 3 patients who also carry BRCA1 c.3049G>T (p.Glu1017X; UMD), 1 patient with BRCA2 c.IVS2+2T>C (c.67+2T>C; UMD), 1 patient with BRCA2 c.51_52delAC (p.Arg18LeufsX12; UMD) and 1 patient with BRCA1 c.5263insC (p.Gln1756fs; Carraro_2013). Additionally, the variant was reported to not segregate with disease in multiple pedigrees, including one family with one affected individual without the variant as well as a second family with two unaffected variant carriers (ages 70 and 90; Lovelock_2006). In another family, the affected proband was positive for the variant, but the variant was not inherited from the cancer affected maternal side of the family (fathers side had no cancer history; Lovelock_2006). Furthermore, multiple reputable clinical labs have classified the variant as likely benign/benign. Therefore, due to the lack of co-segregation of the variant with disease, the co-occurrence of the variant with pathogenic variants in multiple patients, and functional assays showing similar activity to WT BRCA1, this variant has been classified as a benign variant. -
This variant is associated with the following publications: (PMID: 17305420, 15689452, 20378548, 24916970, 21990134, 15923272, 30209399, 23683081, 12955716, 12601471, 23469205, 21702907, 21447777, 23479189, 23289006, 25782689, 15235020, 23867111, 25814778, 27495310, 26997744, 18645608, 20516115, 30145549, 30263132, 28781887, 30765603, 33087888) -
Hereditary cancer-predisposing syndrome Benign:3
This alteration is classified as 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. -
- -
- -
Hereditary breast ovarian cancer syndrome Benign:2
- -
- -
Malignant tumor of breast Benign:1
The BRCA1 p.Gly1706Ala variant has been reported in the literature in 11/1788 proband chromosomes from individuals with hereditary breast and ovarian cancer (Abkevich 2004, Bonatti 2006, Campos 2003, Filippini 2007, Hondow 2011, Lee 2010, Lovelock 2006, Mirkovic 2004, Phelan 2005, Williams 2003) and was not identified in 1100 control chromosomes from healthy individuals (Campos 2003, Phelan 2005). The variant was also identified in dbSNP (ID: rs80356860) with a minor allele frequency of 0.0002 (1000 Genomes Project), LOVD, the ClinVar database (classified as a Likely Benign variant by the Sharing Clinical Reports Project, derived from Myriad reports), the BIC database (6X with unknown clinical importance), and UMD (28X as a UV variant). The variant was also identified by the Exome Variant Server project in 1 of 8600 European American alleles (frequency: 0.0001), although this low number of observations and low frequency is not substantive enough to determine the prevalence of the variant in the general population and its relationship to disease.In the UMD database, this variant has been identified in three individuals with a second pathogenic BRCA1 and BRCA2 variants (c.3049G>T (p.Glu1017X) ; c.IVS2+2T>C (c.67+2T>C), thereby increasing the likelihood that this variant does not have clinical significance. The p.Gly1706 residue is conserved across mammals and lower organisms, and computational analyses (PolyPhen-2, SIFT, AlignGVGD, BLOSUM, MutationTaster) suggest that the p.Gly1706 variant may impact the protein. However, this information is not predictive enough to assume pathogenicity. In addition, several functional assays that examined the variant's protein stability, transcriptional transactivation, and subcellular localization predict this variant to be nonpathogenic (Lee 2010, Lovelock 2006, Williams 2003). In summary, the clinical significance of this variant cannot be determined with certainty at this time, although we would lean towards a more benign role for this variant. This variant is classified as Predicted Benign. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at