rs80357918

Positions:

• chr17-43091660-ATT-A

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_007294.4(BRCA1):​c.3869_3870delAA​(p.Lys1290fs) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,866 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: BRCA1 NM_007294.4 frameshift
• Clinical Significance: Pathogenic reviewed by expert panel P:10
• Conservation: PhyloP100: 1.08

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]

BRCA1 (HGNC:):

ACMG classification

Verdict is Pathogenic. Variant got 18 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 17-43091660-ATT-A is Pathogenic according to our data. Variant chr17-43091660-ATT-A is described in ClinVar as [Pathogenic]. Clinvar id is 55032.Status of the report is reviewed_by_expert_panel, 3 stars. Variant chr17-43091660-ATT-A is described in Lovd as [Pathogenic]. Variant chr17-43091660-ATT-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
BRCA1	NM_007294.4	c.3869_3870delAA	p.Lys1290fs	frameshift_variant	10/23	ENST00000357654.9	NP_009225.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
BRCA1	ENST00000357654.9	c.3869_3870delAA	p.Lys1290fs	frameshift_variant	10/23	1	NM_007294.4	ENSP00000350283.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461866 Hom.: 0 AF XY: 0.00000138 AC XY: 1 AN XY: 727232

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000180

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:10

Revision: reviewed by expert panel

Submissions by phenotype

Breast-ovarian cancer, familial, susceptibility to, 1 Pathogenic:4

Pathogenic, criteria provided, single submitter	clinical testing	Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA), c/o University of Cambridge	Oct 02, 2015	- -
Pathogenic, no assertion criteria provided	clinical testing	Breast Cancer Information Core (BIC) (BRCA1)	May 29, 2002	- -
Pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Apr 18, 2023	- -
Pathogenic, reviewed by expert panel	curation	Evidence-based Network for the Interpretation of Germline Mutant Alleles (ENIGMA)	Apr 22, 2016	Variant allele predicted to encode a truncated non-functional protein. -

not provided Pathogenic:3

Pathogenic, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Feb 22, 2022	- -
Pathogenic, criteria provided, single submitter	clinical testing	Quest Diagnostics Nichols Institute San Juan Capistrano	Sep 23, 2016	- -
Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	May 07, 2019	This deletion of two nucleotides in BRCA1 is denoted c.3869_3870delAA at the cDNA level and p.Lys1290MetfsX4 (K1290MfsX4) at the protein level. The normal sequence, with the bases that are deleted in brackets, is ACAA[delAA]TGTT. The deletion causes a frameshift which changes a Lysine to a Methionine at codon 1290, and creates a premature stop codon at position 4 of the new reading frame. This variant is predicted to cause loss of normal protein function through either protein truncation or nonsense-mediated mRNA decay. BRCA1 c.3869_3870delAA, also published as 3986delAA and 3988delAA using alternate nomenclature, has been reported in association with Hereditary Breast and Ovarian Cancer (Gayther 1999, Malone 2006, de Juan 2015). We consider this variant to be pathogenic. -

Hereditary breast ovarian cancer syndrome Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Jan 03, 2024	This sequence change creates a premature translational stop signal (p.Lys1290Metfs*4) in the BRCA1 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in BRCA1 are known to be pathogenic (PMID: 20104584). This variant is not present in population databases (gnomAD no frequency). This premature translational stop signal has been observed in individual(s) with breast, ovarian, cervical and endometrial cancer and/or a family history of an HBOC-related cancer (PMID: 7606717, 7837387, 10486320, 26026974, 26187060). This variant is also known as 3986delAA and a 2 bp deletion at 3989-3990. ClinVar contains an entry for this variant (Variation ID: 55032). For these reasons, this variant has been classified as Pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Oct 14, 2021	Variant summary: BRCA1 c.3869_3870delAA (p.Lys1290MetfsX4) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. Truncations downstream of this position have been classified as pathogenic by our laboratory. The variant was absent in 252500 control chromosomes (gnomAD and publication). c.3869_3870delAA has been reported in the literature in multiple individuals affected with Hereditary Breast And Ovarian Cancer Syndrome (e.g. Takahashi_1995, Gayther_1999, Judkins_2005, Malone_2006, Couch_2015, de Juan_2015). These data indicate that the variant is very likely to be associated with disease. Six ClinVar submitters including an expert panel (ENIGMA) (evaluation after 2014) cite the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -

Hereditary cancer-predisposing syndrome Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Sep 14, 2022

The c.3869_3870delAA pathogenic mutation, located in coding exon 9 of the BRCA1 gene, results from a deletion of two nucleotides at nucleotide positions 3869 to 3870, causing a translational frameshift with a predicted alternate stop codon (p.K1290Mfs*4). This mutation has previously been reported in families with breast and ovarian cancers (Shattuck-Eidens D et al. JAMA 1995 Feb; 273(7):535-41; de Juan I et al. Fam Cancer 2015 Dec;14(4):505-13). This alteration was identified in a large, worldwide study of BRCA1/2 mutation positive families (Rebbeck TR et al. Hum. Mutat. 2018 05;39:593-620). This alteration has been detected in 1/2575 unselected patients with breast cancer and 0/2809 healthy control individuals from a Malaysian cohort (Wen WX et al. J. Med. Genet. 2018 Feb;55:97-103). This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). In addition to the clinical data presented in the literature, this alteration is expected to result in loss of function by premature protein truncation or nonsense-mediated mRNA decay. As such, this alteration is interpreted as a disease-causing mutation. -

Computational scores

Source: dbNSFP v4.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.040		Details are displayed if max score is > 0.2

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

Publications

LitVar

Other links and lift over

dbSNP: rs80357918; hg19: chr17-41243677;