ENST00000461221.5:n.-98C>G

Variant names:

• chr17-43125386-A-C
• rs1211421601
• ENST00000471181.7:c.-135T>G

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The ENST00000461221.5(BRCA1):​n.-224T>G variant causes a upstream gene change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000983 in 406,738 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency:
  • Genomes: 𝑓 0.000020 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000039 (0 hom.)
• Consequence: BRCA1 ENST00000461221.5 upstream_gene
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.590
• Publications: 0 publications found

Genes affected

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]

NBR2 (HGNC:20691): (neighbor of BRCA1 lncRNA 2) This gene was identified by its close proximity on chromosome 17 to tumor suppressor gene BRCA1. Experimental evidence indicates that the two genes share a bi-directional promoter. Transcription for either gene is controlled individually by distinct transcriptional repressor factors. A short (112 amino acid) open reading frame is observed which includes a region derived from a LINE1 element. A strong Kozak signal is not observed for the putative ORF and the stop codon is more than 55 nucleotides upstream of the last splice site for the transcript, suggesting that the transcript is subject to nonsense-mediated decay. Therefore, this gene does not appear to encode a protein. Glucose starvation induces the expression of this gene and the long non-coding RNA transcribed by it functions with AMP-activated protein kinase in mediating the energy stress response. [provided by RefSeq, Aug 2016]

ACMG classification

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.44).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
BRCA1	NM_007294.4	c.-135T>G		upstream_gene_variant		ENST00000357654.9	NP_009225.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
BRCA1	ENST00000357654.9	c.-135T>G		upstream_gene_variant		1	NM_007294.4	ENSP00000350283.3

Frequencies

GnomAD3 genomes AF: 0.0000197 AC: 3 AN: 152194 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000441

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 0.00000393 AC: 1 AN: 254544 Hom.: 0 Cov.: 0 AF XY: 0.00000701 AC XY: 1 AN XY: 142636

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 6680

American (AMR) AF: 0.00 AC: 0 AN: 20132

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 8244

East Asian (EAS) AF: 0.00 AC: 0 AN: 8398

South Asian (SAS) AF: 0.00 AC: 0 AN: 55030

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 11324

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 1534

European-Non Finnish (NFE) AF: 0.00000761 AC: 1 AN: 131422

Other (OTH) AF: 0.00 AC: 0 AN: 11780

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome AF: 0.0000197 AC: 3 AN: 152194 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74348

African (AFR) AF: 0.00 AC: 0 AN: 41448

American (AMR) AF: 0.00 AC: 0 AN: 15278

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3470

East Asian (EAS) AF: 0.00 AC: 0 AN: 5192

South Asian (SAS) AF: 0.00 AC: 0 AN: 4832

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10618

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.0000441 AC: 3 AN: 68038

Other (OTH) AF: 0.00 AC: 0 AN: 2090

Alfa AF: 0.0000843 Hom.: 0

Bravo AF: 0.0000189

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.44
CADD	Benign	17
DANN	Benign	0.87
PhyloP100		0.59
PromoterAI		-0.089	Neutral

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs1211421601; hg19: chr17-41277403;