rs397507234
Variant summary
Our verdict is Likely benign. Variant got -5 ACMG points: 0P and 5B. BP4_StrongBP6
The NM_007294.4(BRCA1):c.4485-8C>T variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000701 in 1,611,770 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).
Frequency
Consequence
NM_007294.4 splice_region, intron
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: 0.0000197 AC: 3AN: 152156Hom.: 0 Cov.: 31
GnomAD3 exomes AF: 0.00000399 AC: 1AN: 250888Hom.: 0 AF XY: 0.00 AC XY: 0AN XY: 135620
GnomAD4 exome AF: 0.0000754 AC: 110AN: 1459614Hom.: 0 Cov.: 30 AF XY: 0.0000688 AC XY: 50AN XY: 726250
GnomAD4 genome AF: 0.0000197 AC: 3AN: 152156Hom.: 0 Cov.: 31 AF XY: 0.0000135 AC XY: 1AN XY: 74336
ClinVar
Submissions by phenotype
not provided Uncertain:2Benign:2
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The BRCA1 c.4485-8C>T variant was identified in 1 of 300 proband chromosomes (frequency: 0.003) from individuals or families with breast cancer (Flower 2015). The variant was also identified in the following databases: dbSNP (ID: rs397507234) as "With other allele", ClinVar (2x uncertain significance, 3x likely benign), Clinvitae, Cosmic (1x, confirmed somatic, in carcinoma of the ovary), and LOVD 3.0 (1x). The variant was classified as a likely benign variant by the Sharing Clinical Reports Project (SCRP, derived from Myriad reports). The variant was not identified in the following databases: COGR, MutDB, UMD-LSDB, BIC Database, ARUP Laboratories, or the Zhejiang University Database. The variant was identified in control databases in 2 of 276702 chromosomes at a frequency of 0.000007 (Genome Aggregation Database Feb 27, 2017). It was observed in the European population in 2 of 126368 chromosomes (freq: 0.00002); it was not observed in the African, Other, Latino, Ashkenazi Jewish, East Asian, Finnish, or South Asian populations. This variant was classified as “likely non-pathogenic or of little clinical significance” based on the methylation profile in a breast tumour sample (Flower 2015). The c.4485-8C>T variant is located in the 3' splice region but does not affect the invariant -1 and -2 positions. However, positions -3 and -5 to -12 are part of the splicing consensus sequence and variants involving these positions sometimes affect splicing. However, in silico or computational prediction software programs (SpliceSiteFinder, MaxEntScan, NNSPLICE, GeneSplicer, HumanSpliceFinder) do not predict a difference in splicing. 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. -
The frequency of this variant in the general population, 0.0000071 (2/282280 chromosomes, http://gnomad.broadinstitute.org), is uninformative in assessment of its pathogenicity. In the published literature, the variant has been reported in one family from a cohort of 146 high-risk families with BRCA1 and BRCA2 variants (PMID: 22476429 (2012)). A functional study of breast cancer tumors has reported the variant has an uncertain impact on protein function, however further studies are required to determine the global impact of this variant on BRCA1 protein function (PMID: 26727311 (2015)). Analysis of this variant using software algorithms for the prediction of the effect of nucleotide changes on splicing yielded predictions that this variant does not affect BRCA1 mRNA splicing . Based on the available information, we are unable to determine the clinical significance of this variant. -
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Breast-ovarian cancer, familial, susceptibility to, 1 Uncertain:1Benign:1
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not specified Benign:1
Variant summary: BRCA1 c.4485-8C>T alters a non-conserved nucleotide located at a position not widely known to affect splicing. Consensus agreement among computation tools predict no significant impact on normal splicing. However, these predictions have yet to be confirmed by functional studies. The variant allele was found at a frequency of 4e-06 in 250888 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.4485-8C>T has been reported in the literature in affected individuals without strong evidence for or against pathogenicity (Lu_2012, Flower_2015 ). These report(s) do not provide unequivocal conclusions about association of the variant with Hereditary Breast And Ovarian Cancer Syndrome. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 26727311, 22476429, 33233347). ClinVar contains an entry for this variant (Variation ID: 37599). Based on the evidence outlined above, the variant was classified as likely benign. -
BRCA1-related cancer predisposition Benign:1
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Hereditary cancer-predisposing syndrome Benign:1
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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