17-43093163-T-C
Variant summary
Our verdict is Likely benign. Variant got -5 ACMG points: 0P and 5B. BP4_StrongBP6
The NM_007294.4(BRCA1):c.2368A>G(p.Thr790Ala) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00007 in 1,613,726 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 Conflicting classifications of pathogenicity (no stars).
Frequency
Consequence
NM_007294.4 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Likely_benign. Variant got -5 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.000276 AC: 42AN: 152118Hom.: 0 Cov.: 32
GnomAD3 exomes AF: 0.0000718 AC: 18AN: 250612Hom.: 0 AF XY: 0.0000443 AC XY: 6AN XY: 135440
GnomAD4 exome AF: 0.0000486 AC: 71AN: 1461490Hom.: 0 Cov.: 41 AF XY: 0.0000344 AC XY: 25AN XY: 727020
GnomAD4 genome AF: 0.000276 AC: 42AN: 152236Hom.: 0 Cov.: 32 AF XY: 0.000255 AC XY: 19AN XY: 74450
ClinVar
Submissions by phenotype
not provided Uncertain:3Benign:2
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The p.Thr790Ala variant in BRCA1 has been reported in at >10 individuals with breast or ovarian cancer, the majority of which were Black or African-American (Haffty 2005 PMID: 15983021, Lee 2008 PMID: 18284688, Rummel 2013 PMID: 23192404, Pal 2015 PMID: 26287763, Cortes 2019 PMID: 31341521, Cotrim 2019 PMID: 30606148; Breast Cancer information Core (BIC)). It has also been identified in 0.1% (25/24960) of African or African-American chromosomes by gnomAD (http://gnomad.broadinstitute.org). This variant has been reported in ClinVar (Variation ID 37465). Computational prediction tools and conservation analyses suggest that this variant may not impact the protein, including the presence of Alanine (Ala) at this position in two mammals, though this information is not predictive enough to rule out pathogenicity. In summary, while the clinical significance of this variant is uncertain, these frequency and lack of conservation suggest that it is more likely to be benign. ACMG/AMP Criteria applied: PS4_Moderate, BP4, BS1_Supporting. -
This variant is associated with the following publications: (PMID: 15983021, 23192404, 16267036, 22875147, 18284688, 16518693, 31341521, 30606148) -
The BRCA1 c.2368A>G; p.Thr790Ala variant (rs41286298) is reported in the literature in multiple individuals affected with breast cancer (Cortes 2019, Haffty 2006, Lee 2008, Rummel 2013). However, this variant is also reported to co-occur with pathogenic variants in BRCA1 or BRCA2 by other laboratories in ClinVar (Variant ID: 37465), and is found in the African population with an allele frequency of 0.10% (25/24960 alleles) in the Genome Aggregation Database. The threonine at codon 790 is moderately conserved, and computational analyses (SIFT: tolerated, PolyPhen-2: possibly damaging) predict conflicting effects of this variant on protein structure/function. Although there is evidence to support a benign role for this variant, due to insufficent information, the clinical significance of is uncertain at this time. References: Cortes C et al. Mutational analysis of BRCA1 and BRCA2 genes in women with familial breast cancer from different regions of Colombia. Hered Cancer Clin Pract. 2019 Jul 15;17:20. Haffty BG et al. Racial differences in the incidence of BRCA1 and BRCA2 mutations in a cohort of early onset breast cancer patients: African American compared to white women. J Med Genet. 2006 Feb;43(2):133-7. Lee E et al. Evaluation of unclassified variants in the breast cancer susceptibility genes BRCA1 and BRCA2 using five methods: results from a population-based study of young breast cancer patients. Breast Cancer Res. 2008;10(1):R19. Rummel S et al. Evaluation of BRCA1 mutations in an unselected patient population with triple-negative breast cancer. Breast Cancer Res Treat. 2013 Jan;137(1):119-25. -
Hereditary cancer-predisposing syndrome Uncertain:1Benign:3
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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. -
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Missense variant in a coldspot region where missense variants are very unlikely to be pathogenic (PMID:31911673). -
Breast-ovarian cancer, familial, susceptibility to, 1 Uncertain:1Benign:1
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not specified Benign:2
Variant summary: BRCA1 c.2368A>G (p.Thr790Ala) results in a non-conservative amino acid change in the encoded protein sequence. Three of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 9.9e-05 in 282008 control chromosomes, predominantly within the African subpopulation at a frequency of 0.001 in the gnomAD database. This frequency is about the same as expected for a pathogenic variant in BRCA1 causing Hereditary Breast and Ovarian Cancer (0.001 vs 0.001), suggesting a benign role for the variant. c.2368A>G has been reported in the literature in several individuals of African and/or African American ancestry affected with Hereditary Breast and Ovarian Cancer. Due to the similarity in the ethnicity between control chromosomes and published reports, these occurrences do not provide unequivocal conclusions about association of the variant with Hereditary Breast and Ovarian Cancer. Co-occurrences with other pathogenic BRCA1 variants have been reported in the UMD database (c.5324T>G (p.Met1775Arg) in one individual and c.1961dup (p.Tyr655valfsX18) in another), in addition, several co-occurrences with pathogenic BRCA2 variants have also been reported (in the BIC database: c.5946_5946delT (p.Ser1982fsX22) in one individual, and c.8948_8953+5delATTCAGGTAAG in two other individuals; and in LCA internal samples: c.2808delA (p.Lys936fsX24) in one individual and c.5351dupA (p.Asn1784fsX3) in another individual). These multiple co-occurrences strongly support a benign role for the variant. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Three other clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation, and classified the variant as Benign (1x) / Likely benign (2x). Based on the evidence outlined above, the variant was re-classified as benign. -
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Breast and/or ovarian cancer Uncertain:1
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Malignant tumor of breast Uncertain:1
The BRCA1 p.Thr790Ala variant was identified in the literature in an African American individual with breast cancer; however, control chromosomes from healthy individuals were not evaluated in this study (Haffty 2005). The variant was also identified in dbSNP (ID: rs41286298) “With unknown allele”, BIC (8X with unknown clinical importance) and UMD (1X as an unclassified variant). Within the UMD record, the variant was noted to co-occur with a known pathogenic mutation in BRCA1 (c.5324T>G (p.Met1775Arg)), increasing the likelihood that the p.Thr790Ala variant may not have clinical significance. In addition, the variant was reported in three of 4460 African American chromosomes (frequency: 0.0007) from the Exome Variant Server ESP Project, increasing the likelihood that may be a low frequency benign variant in certain populations of origin. The p.Thr790 residue is conserved in mammals; however, computational analyses (PolyPhen-2, SIFT, AlignGVGD) provide inconsistent predictions regarding the impact to the protein and this information 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 unknown significance. -
BRCA1-related disorder Benign:1
This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -
Hereditary breast ovarian cancer syndrome Benign:1
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Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at