rs80358335

Positions:

• chr17-43092200-GCTT-G

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 1P and 1B. PM4_Supporting BP6

The NM_007294.4(BRCA1):​c.3328_3330del​(p.Lys1110del) variant causes a inframe deletion change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000164 in 1,612,992 control chromosomes in the GnomAD database, including 1 homozygotes. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: 𝑓 0.000053 (0 hom., cov: 32)
  • Exomes 𝑓: 0.00018 (1 hom.)
• Consequence: BRCA1 NM_007294.4 inframe_deletion
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:9 B:12
• Conservation: PhyloP100: -0.372

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

• PM4: Nonframeshift variant in NON repetitive region in NM_007294.4. Strenght limited to Supporting due to length of the change: 1aa.
• BP6: Variant 17-43092200-GCTT-G is Benign according to our data. Variant chr17-43092200-GCTT-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 54840.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=7, Uncertain_significance=6, Benign=2}. Variant chr17-43092200-GCTT-G is described in Lovd as [Likely_benign].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
BRCA1	NM_007294.4	c.3328_3330del	p.Lys1110del	inframe_deletion	10/23	ENST00000357654.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
BRCA1	ENST00000357654.9	c.3328_3330del	p.Lys1110del	inframe_deletion	10/23	1	NM_007294.4	P4

Frequencies

GnomAD3 genomes AF: 0.0000526 AC: 8 AN: 152092 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: 0.00166

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.000396 AC: 99 AN: 250222 Hom.: 1 AF XY: 0.000583 AC XY: 79 AN XY: 135406

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00324

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.000175 AC: 256 AN: 1460900 Hom.: 1 AF XY: 0.000283 AC XY: 206 AN XY: 726756

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000224

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00292

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.0000331

GnomAD4 genome AF: 0.0000526 AC: 8 AN: 152092 Hom.: 0 Cov.: 32 AF XY: 0.0000808 AC XY: 6 AN XY: 74292

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00166

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

Alfa AF: 0.0000712 Hom.: 0

Bravo AF: 0.00000756

Asia WGS AF: 0.000289 AC: 1 AN: 3478

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:9 Benign:12

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Uncertain:3 Benign:5

Benign, criteria provided, single submitter	clinical testing	Quest Diagnostics Nichols Institute San Juan Capistrano	Jan 14, 2019	- -
Likely benign, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	Oct 01, 2023	BRCA1: PM4:Supporting, BS3:Supporting, BS2 -
Uncertain significance, criteria provided, single submitter	clinical testing	ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories	Nov 05, 2019	The BRCA1 c.3328_3330delAAG; p.Lys1110del variant (rs80358335) is reported in the literature in individuals with breast and/or ovarian cancer (Ahmad 2012, Mannan 2016, Mehta 2018), and is reported in ClinVar (Variation ID: 54840). This variant is found in the South Asian population with an allele frequency of 0.3% (99/30598 alleles, including 1 homozygote) in the Genome Aggregation Database. The lysine at codon 1110 is not highly conserved and does not occur in a known functional domain. Additionally, at least one functional study shows this variant is able to complement the growth defect of BRCA1 null cells, suggesting the variant does not impair BRCA1 function (Bouwman 2013). However, due to limited information, the clinical significance of this variant is uncertain at this time. REFERENCES Ahmad J et al. Detection of BRCA1/2 mutations in breast cancer patients from Thailand and Pakistan. Clin Genet. 2012 Dec;82(6):594-8. Bouwman P et al. A high-throughput functional complementation assay for classification of BRCA1 missense variants. Cancer Discov. 2013 Oct;3(10):1142-55. Mannan AU et al. Detection of high frequency of mutations in a breast and/or ovarian cancer cohort: implications of embracing a multi-gene panel in molecular diagnosis in India. J Hum Genet. 2016 Jun;61(6):515-22. Mehta A et al. Germline BRCA1 and BRCA2 deleterious mutations and variants of unknown clinical significance associated with breast/ovarian cancer: a report from North India. Cancer Manag Res. 2018 Nov 30;10:6505-6516. -
Likely benign, no assertion criteria provided	clinical testing	Laboratory of Diagnostic Genome Analysis, Leiden University Medical Center (LUMC)	-	- -
Likely benign, criteria provided, single submitter	clinical testing	GeneDx	Jul 29, 2022	See Variant Classification Assertion Criteria. -
Likely benign, no assertion criteria provided	clinical testing	Diagnostic Laboratory, Department of Genetics, University Medical Center Groningen	-	- -
Uncertain significance, no assertion criteria provided	clinical testing	Department of Pathology and Laboratory Medicine, Sinai Health System	-	The BRCA1 p.Lys1110del variant was identified in at least 1 of 55630 proband chromosomes from individuals or families with breast or ovarian cancer (Judkins 2005). The variant was also identified in dbSNP (ID: rs80358335) “With Uncertain significance allele”, the Exome Aggregation Consortium (ExAC) database (released Jan 13, 2015) in 54 of 121128 chromosomes (frequency: 0.0004), or 54 individuals from a population of South Asian individuals, and none from European (Non-Finnish), East Asian, Other, African, Latino, or European (Finnish) individuals; and the ClinVar database (classified as a variant with uncertain significance by BIC, Ambry Genetics and Molecular Genetics Diagnostic Laboratory, CHEO and classification not provided by Invitae), and GeneInsight COGR database(3X, classified as “unknown significance” by 2 clinical laboratories, and unclassified by another). This variant is an in-frame deletion resulting in the removal of a lysine (Lys) residue at codon 1110; however, the impact of this alteration on BRCA1 protein function is not known. A cDNA-based functional complementation assay using BRCA1-deficient mouse embryonic stem cells, classified the variant as neutral by restoring cell proliferation and showing cisplatin sensitivity at levels similar to wild-type BRCA1 protein (Bouwman 2013). However, the impact of this alteration on other aspects of BRCA1 protein function is not known. 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. -
Uncertain significance, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Feb 09, 2021	- -

Breast-ovarian cancer, familial, susceptibility to, 1 Uncertain:5 Benign:1

Likely benign, no assertion criteria provided	clinical testing	Sharing Clinical Reports Project (SCRP)	Nov 11, 2008	- -
Uncertain significance, no assertion criteria provided	clinical testing	Breast Cancer Information Core (BIC) (BRCA1)	Feb 20, 2004	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Molecular Endocrinology Laboratory, Christian Medical College	-	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Counsyl	Dec 22, 2015	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center	Sep 21, 2015	- -
Uncertain significance, no assertion criteria provided	clinical testing	KCCC/NGS Laboratory, Kuwait Cancer Control Center	May 05, 2023	We detected an in-frame deletion in the BRCA1 gene (c.3328_3330delAAG) which results in the deletion of the amino acid lysine at position 1110. This mutation is considered as a variant of unknown significance. -

Hereditary cancer-predisposing syndrome Benign:3

Likely benign, criteria provided, single submitter	clinical testing	Ambry Genetics	Mar 30, 2019	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. -
Likely benign, criteria provided, single submitter	curation	Sema4, Sema4	Mar 11, 2022	- -
Likely benign, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Jun 01, 2015	- -

Hereditary breast ovarian cancer syndrome Uncertain:1 Benign:1

Uncertain significance, criteria provided, single submitter	clinical testing	National Health Laboratory Service, Universitas Academic Hospital and University of the Free State	Apr 19, 2022	- -
Benign, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Jan 28, 2024	- -

not specified Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Jul 07, 2023

Variant summary: BRCA1 c.3328_3330delAAG (p.Lys1110del) results in an in-frame deletion that is predicted to remove one amino acids from the encoded protein. The variant allele was found at a frequency of 0.00039 in 250772 control chromosomes, predominantly at a frequency of 0.0032 within the South Asian subpopulation in the gnomAD database, including 1 homozygotes. The observed variant frequency within South Asian control individuals in the gnomAD database is above 3 fold of the estimated maximal expected allele frequency for a pathogenic variant in BRCA1 causing Hereditary Breast And Ovarian Cancer Syndrome phenotype (0.001), strongly suggesting that the variant is a benign polymorphism found primarily in populations of South Asian origin. c.3328_3330delAAG has been reported in the literature in individuals affected with Hereditary Breast and Ovarian Cancer, without strong evidence for causality, and was additionally found in an unaffected individual in the literature (Mannan_2016). Experimental evidence including an HDR assay evaluating impact on protein function showed no damaging effect of this variant (Bouwman_2013, Bouwman_2020). The following publications have been ascertained in the context of this evaluation (PMID: 22486713, 23867111, 32546644, 25036526, 16267036, 26911350, 29785135, 28263838, 19370767). Multiple submitters have cited clinical-significance assessments for this variant to ClinVar after 2014 and classified as benign/likely benign (n=7) and VUS (n=6). Based on the evidence outlined above, the variant was classified as likely benign. -

Breast and/or ovarian cancer Benign:1

Likely benign, criteria provided, single submitter

clinical testing

CHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern Ontario

Jul 24, 2018

- -

Computational scores

Source: dbNSFP v4.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		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: rs80358335; hg19: chr17-41244217;