8-89955337-T-A

Position:

chr8-89955337-T-A

Variant summary

Our verdict is Likely benign. Variant got -5 ACMG points: 0P and 5B. BP4_StrongBP6

The NM_002485.5(NBN):c.1343A>T(p.Gln448Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000235 in 1,613,890 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.00016 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000096 ( 0 hom. )

Consequence

NBN
NM_002485.5 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:10B:2

Conservation

PhyloP100: 1.86

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:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -5 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.03677994).

BP6

Variant 8-89955337-T-A is Benign according to our data. Variant chr8-89955337-T-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 182720.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=2, Uncertain_significance=8}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
NBN	NM_002485.5 linkuse as main transcript	c.1343A>T	p.Gln448Leu	missense_variant	10/16	ENST00000265433.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
NBN	ENST00000265433.8 linkuse as main transcript	c.1343A>T	p.Gln448Leu	missense_variant	10/16	1	NM_002485.5	P1

Frequencies

GnomAD3 genomes

AF:

0.000158

AC:

AN:

152176

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000579

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:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000398

AC:

AN:

251212

Hom.:

AF XY:

0.0000368

AC XY:

AN XY:

135778

show subpopulations

Gnomad AFR exome

AF:

0.000616

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000958

AC:

AN:

1461596

Hom.:

Cov.:

AF XY:

0.0000110

AC XY:

AN XY:

727096

show subpopulations

Gnomad4 AFR exome

AF:

0.000388

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:

0.0000166

GnomAD4 genome

AF:

0.000158

AC:

AN:

152294

Hom.:

Cov.:

AF XY:

0.000188

AC XY:

AN XY:

74470

show subpopulations

Gnomad4 AFR

AF:

0.000577

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:

0.00

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000868

Hom.:

Bravo

AF:

0.000178

ESP6500AA

AF:

0.000227

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.0000412

AC:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:10Benign:2

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Uncertain:4

Uncertain significance, criteria provided, single submitter	clinical testing	GeneDx	Jul 22, 2022	In silico analysis supports that this missense variant does not alter protein structure/function; Observed in an individual with breast cancer (Tung et al., 2015); This variant is associated with the following publications: (PMID: 25186627) -
Uncertain significance, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Feb 05, 2019	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Quest Diagnostics Nichols Institute San Juan Capistrano	Aug 30, 2023	In the published literature, this variant has been reported in an individual with breast cancer (PMID: 25186627 (2015)). The frequency of this variant in the general population, 0.00048 (12/24954 chromosomes (Genome Aggregation Database, http://gnomad.broadinstitute.org)), is uninformative in the assessment of its pathogenicity. Analysis of this variant using bioinformatics tools for the prediction of the effect of amino acid changes on protein structure and function yielded predictions that this variant is benign. Based on the available information, we are unable to determine the clinical significance of this variant. -
Uncertain significance, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Dec 17, 2014	- -

Microcephaly, normal intelligence and immunodeficiency

Uncertain:2Benign:1

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	- -
Likely benign, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Jan 19, 2024	- -

Hereditary cancer-predisposing syndrome

Uncertain:1Benign:1

Uncertain significance, criteria provided, single submitter	curation	Sema4, Sema4	Nov 23, 2021	- -
Likely benign, criteria provided, single submitter	clinical testing	Ambry Genetics	Jan 10, 2022	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. -

not specified

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

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

Oct 09, 2020

Variant summary: NBN c.1343A>T (p.Gln448Leu) results in a non-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 4e-05 in 251212 control chromosomes, predominantly at a frequency of 0.00062 within the African or African-American subpopulation in the gnomAD database. This frequency is not significantly higher than expected for a pathogenic variant in NBN causing Nijmegen Breakage Syndrome (0.00062 vs 0.0025), allowing no conclusion about variant significance. c.1343A>T has been reported in the literature in at least one individual affected with breast cancer (Tung_2014). This report does 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. Five other clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as uncertain significance. -

Aplastic anemia

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Baylor Genetics

Mar 29, 2024

- -

NBN-related disorder

Uncertain:1

Uncertain significance, no assertion criteria provided

clinical testing

PreventionGenetics, part of Exact Sciences

May 14, 2024

The NBN c.1343A>T variant is predicted to result in the amino acid substitution p.Gln448Leu. This variant was identified in an individual with early onset (<50) breast cancer, but was classified as a variant of uncertain significance (Supplementary data, Tung et al. 2015. PubMed ID: 25186627). This variant is reported in 0.048% of alleles in individuals of African descent in gnomAD, and has conflicting classifications in ClinVar ranging from uncertain to likely benign (https://www.ncbi.nlm.nih.gov/clinvar/variation/182720/). At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.099

BayesDel_addAF

Benign

-0.30

BayesDel_noAF

Benign

-0.31

CADD

Benign

DANN

Uncertain

0.98

DEOGEN2

Benign

0.25

T;T

Eigen

Benign

-0.34

Eigen_PC

Benign

-0.29

FATHMM_MKL

Uncertain

0.77

LIST_S2

Benign

0.63

T;T

M_CAP

Benign

0.014

MetaRNN

Benign

0.037

T;T

MetaSVM

Benign

-0.92

MutationAssessor

Uncertain

2.7

M;.

MutationTaster

Benign

1.0

N;N

PrimateAI

Benign

0.30

PROVEAN

Benign

-1.9

N;N

REVEL

Benign

0.037

Sift

Uncertain

0.029

D;D

Sift4G

Benign

0.14

T;T

Polyphen

0.099

B;.

Vest4

0.37

MVP

0.71

MPC

0.074

ClinPred

0.087

GERP RS

2.4

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Varity_R

0.058

gMVP

0.25

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