chr17-61849198-T-C

Position:

• chr17-61849198-T-C

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 4P and 2B. PM1 PM2 BP4_Moderate

The NM_032043.3(BRIP1):​c.438A>G​(p.Ile146Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000685 in 1,460,712 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. I146V) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: BRIP1 NM_032043.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:4
• Conservation: PhyloP100: -1.49

Genes affected

BRIP1 (HGNC:20473): (BRCA1 interacting helicase 1) The protein encoded by this gene is a member of the RecQ DEAH helicase family and interacts with the BRCT repeats of breast cancer, type 1 (BRCA1). The bound complex is important in the normal double-strand break repair function of breast cancer, type 1 (BRCA1). This gene may be a target of germline cancer-inducing mutations. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 16 uncertain in NM_032043.3
• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.24884889).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
BRIP1	NM_032043.3	c.438A>G	p.Ile146Met	missense_variant	5/20	ENST00000259008.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
BRIP1	ENST00000259008.7	c.438A>G	p.Ile146Met	missense_variant	5/20	1	NM_032043.3	P2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.85e-7 AC: 1 AN: 1460712 Hom.: 0 Cov.: 30 AF XY: 0.00 AC XY: 0 AN XY: 726732

Gnomad4 AFR exome AF: 0.0000299

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: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Ambry Genetics	Jul 12, 2023	The p.I146M variant (also known as c.438A>G), located in coding exon 4 of the BRIP1 gene, results from an A to G substitution at nucleotide position 438. The isoleucine at codon 146 is replaced by methionine, an amino acid with highly similar properties. This amino acid position is not conserved however, methionine is a reference amino acid in several species. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -
Uncertain significance, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Oct 19, 2020	This missense variant replaces isoleucine with methionine at codon 146 of the BRIP1 protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with hereditary cancer in the literature. This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -

Familial cancer of breast;C1836860:Fanconi anemia complementation group J Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Oct 20, 2022

This sequence change replaces isoleucine, which is neutral and non-polar, with methionine, which is neutral and non-polar, at codon 146 of the BRIP1 protein (p.Ile146Met). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with BRIP1-related conditions. ClinVar contains an entry for this variant (Variation ID: 824852). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt BRIP1 protein function. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Jan 27, 2023

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.063
BayesDel_addAF	Benign	-0.33	T
BayesDel_noAF	Benign	-0.72
CADD	Benign	0.49
DANN	Benign	0.51
DEOGEN2	Benign	0.095	T;.
Eigen	Benign	-1.4
Eigen_PC	Benign	-1.5
FATHMM_MKL	Benign	0.049	N
LIST_S2	Benign	0.095	T;T
M_CAP	Benign	0.014	T
MetaRNN	Benign	0.25	T;T
MetaSVM	Benign	-1.1	T
MutationAssessor	Benign	-0.035	N;N
MutationTaster	Benign	1.0	N;N
PrimateAI	Benign	0.25	T
PROVEAN	Benign	-0.31	N;.
REVEL	Benign	0.018
Sift	Benign	0.24	T;.
Sift4G	Benign	0.23	T;T
Polyphen		0.053	B;.
Vest4		0.13
MutPred		0.39		Gain of MoRF binding (P = 0.0939);Gain of MoRF binding (P = 0.0939);
MVP		0.21
MPC		0.17
ClinPred		0.11	T
GERP RS		-6.6
Varity_R		0.029
gMVP		0.15

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: rs886038702; hg19: chr17-59926559;