8-89971231-C-T

Position:

chr8-89971231-C-T

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 0P and 2B. BP4_Moderate

The NM_002485.5(NBN):c.644G>A(p.Arg215Gln) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000026 in 1,613,014 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/21 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. R215W) has been classified as Benign.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000027 ( 0 hom. )

Consequence

NBN
NM_002485.5 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:13

Conservation

PhyloP100: 0.958

Variant links:

Genes affected

NBN (HGNC:7652): (nibrin) Mutations in this gene are associated with Nijmegen breakage syndrome, an autosomal recessive chromosomal instability syndrome characterized by microcephaly, growth retardation, immunodeficiency, and cancer predisposition. The encoded protein is a member of the MRE11/RAD50 double-strand break repair complex which consists of 5 proteins. This gene product is thought to be involved in DNA double-strand break repair and DNA damage-induced checkpoint activation. [provided by RefSeq, Jul 2008]

NBN links:

NBN (HGNC:):

NBN links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -2 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.18622962).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
NBN	NM_002485.5 linkuse as main transcript	c.644G>A	p.Arg215Gln	missense_variant	6/16	ENST00000265433.8	NP_002476.2	O60934

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
NBN	ENST00000265433.8 linkuse as main transcript	c.644G>A	p.Arg215Gln	missense_variant	6/16	1	NM_002485.5	ENSP00000265433.4		O60934

Frequencies

GnomAD3 genomes

AF:

0.0000132

AC:

AN:

152050

Hom.:

Cov.:

show subpopulations

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:

0.0000294

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000239

AC:

AN:

250882

Hom.:

AF XY:

0.0000442

AC XY:

AN XY:

135658

show subpopulations

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:

0.0000327

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000441

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000274

AC:

AN:

1460964

Hom.:

Cov.:

AF XY:

0.0000289

AC XY:

AN XY:

726804

show subpopulations

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:

0.0000116

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000342

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000132

AC:

AN:

152050

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74262

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000294

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.000116

Hom.:

Bravo

AF:

0.0000529

ExAC

AF:

0.0000165

AC:

EpiCase

AF:

0.0000546

EpiControl

AF:

0.00

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:13

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Microcephaly, normal intelligence and immunodeficiency

Uncertain:5

Uncertain significance, criteria provided, single submitter	clinical testing	Counsyl	Apr 03, 2018	- -
Uncertain significance, no assertion criteria provided	clinical testing	Natera, Inc.	Sep 16, 2020	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Nov 07, 2021	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Jan 04, 2024	This sequence change replaces arginine, which is basic and polar, with glutamine, which is neutral and polar, at codon 215 of the NBN protein (p.Arg215Gln). This variant is present in population databases (rs61753718, gnomAD 0.005%). This variant has not been reported in the literature in individuals affected with NBN-related conditions. ClinVar contains an entry for this variant (Variation ID: 141888). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. 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. -
Uncertain significance, criteria provided, single submitter	clinical testing	St. Jude Molecular Pathology, St. Jude Children's Research Hospital	Oct 07, 2022	The NBN c.644G>A (p.Arg215Gln) missense change has a maximum subpopulation frequency of 0.0047% in gnomAD v2.1.1 (https://gnomad.broadinstitute.org/). The in silico tool REVEL predicts a benign effect on protein function, but to our knowledge this prediction has not been confirmed by functional studies. This variant has been reported in a large case-control study of breast cancer in 4 of 60,466 cases and 5 of 53,461 controls (PMID: 33471991). To our knowledge, this variant has not been reported in individuals with Nijmegan breakage syndrome. In summary, the evidence currently available is insufficient to determine the clinical significance of this variant. It has therefore been classified as of uncertain significance. -

not provided

Uncertain:3

Uncertain significance, criteria provided, single submitter	clinical testing	GeneDx	May 11, 2023	In silico analysis supports that this missense variant does not alter protein structure/function; Observed in cases and controls in a breast cancer study (Dorling et al., 2021); This variant is associated with the following publications: (PMID: 31278556, 33471991) -
Uncertain significance, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Mar 08, 2022	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Quest Diagnostics Nichols Institute San Juan Capistrano	Mar 12, 2019	- -

not specified

Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Sep 09, 2024	Variant summary: NBN c.644G>A (p.Arg215Gln) results in a conservative amino acid change in the encoded protein sequence. Four of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 2.4e-05 in 250882 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.644G>A has been reported in the literature in a cohort of individuals with increased risk of cancer (Belhadj_2023). These report(s) do not provide unequivocal conclusions about association of the variant with Nijmegen Breakage Syndrome. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publication has been ascertained in the context of this evaluation (PMID: 36346689). ClinVar contains an entry for this variant (Variation ID: 141888). Based on the evidence outlined above, the variant was classified as uncertain significance. -
Uncertain significance, criteria provided, single submitter	clinical testing	Genetic Services Laboratory, University of Chicago	Mar 19, 2020	DNA sequence analysis of the NBN gene demonstrated a sequence change, c.644G>A, in exon 6 that results in an amino acid change, p.Arg215Gln. This sequence change does not appear to have been previously described in patients with NBN-related disorders and has been described in the gnomAD database with a low population frequency of 0.0047% in the non-Finnish European subpopulation (dbSNP rs61753718). The p.Arg215Gln change affects a moderatel conserved amino acid residue located in a domain of the NBN protein that is not known to be functional. In-silico pathogenicity prediction tools (SIFT, PolyPhen2, Align GVGD, REVEL) provide contradictory results for the p.Arg215Gln substitution. Due to these contrasting evidences and the lack of functional studies, the clinical significance of the p.Arg215Gln change remains unknown at this time. -

Hereditary cancer-predisposing syndrome

Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Ambry Genetics	Oct 23, 2024	The p.R215Q variant (also known as c.644G>A), located in coding exon 6 of the NBN gene, results from a G to A substitution at nucleotide position 644. The arginine at codon 215 is replaced by glutamine, an amino acid with highly similar properties. This variant was reported in 4/60,466 breast cancer cases and in 5/53,461 controls (Dorling et al. N Engl J Med. 2021 02;384:428-439). This amino acid position is not well conserved in available vertebrate 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	curation	Sema4, Sema4	Dec 05, 2021	- -

Aplastic anemia

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Baylor Genetics

Feb 13, 2024

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.096

BayesDel_addAF

Benign

-0.16

BayesDel_noAF

Benign

-0.34

CADD

Benign

DANN

Uncertain

1.0

DEOGEN2

Benign

0.18

T;T;.;.

Eigen

Benign

0.17

Eigen_PC

Benign

0.10

FATHMM_MKL

Benign

0.068

LIST_S2

Uncertain

0.94

D;D;D;D

M_CAP

Benign

0.062

MetaRNN

Benign

0.19

T;T;T;T

MetaSVM

Benign

-0.46

MutationAssessor

Uncertain

2.4

M;.;.;.

PrimateAI

Benign

0.27

PROVEAN

Benign

-1.3

N;N;N;N

REVEL

Benign

0.20

Sift

Benign

0.14

T;T;T;T

Sift4G

Benign

0.48

T;T;T;.

Polyphen

1.0

D;.;.;.

Vest4

0.29

MutPred

0.43

Loss of MoRF binding (P = 0.015);.;.;.;

MVP

0.87

MPC

0.24

ClinPred

0.55

GERP RS

4.0

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Varity_R

0.053

gMVP

0.40

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over