Genetic Variant NBN:p.Ala183Thr (chr8-89978257-C-T) – ACMG Classification: Likely_benign (-1 pts)

Variant summary

Our verdict is Likely benign. Variant got -1 ACMG points: 0P and 1B. BP4

The NM_002485.5(NBN):c.547G>A(p.Ala183Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000174 in 1,605,426 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.000026 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000017 ( 0 hom. )

Consequence

NBN
NM_002485.5 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:7

Conservation

PhyloP100: 3.26

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 -1 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.34444106).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
NBN	NM_002485.5 link	c.547G>A	p.Ala183Thr	missense_variant	Exon 5 of 16	ENST00000265433.8	NP_002476.2	O60934

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
NBN	ENST00000265433.8 link	c.547G>A	p.Ala183Thr	missense_variant	Exon 5 of 16	1	NM_002485.5	ENSP00000265433.4		O60934

Frequencies

GnomAD3 genomes

AF:

0.0000263

AC:

AN:

152118

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:

0.0000588

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000159

AC:

AN:

251320

Hom.:

AF XY:

0.0000221

AC XY:

AN XY:

135832

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.0000992

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000264

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000165

AC:

AN:

1453308

Hom.:

Cov.:

AF XY:

0.0000221

AC XY:

AN XY:

723648

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.0000384

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000190

Gnomad4 OTH exome

AF:

0.0000333

GnomAD4 genome

AF:

0.0000263

AC:

AN:

152118

Hom.:

Cov.:

AF XY:

0.0000538

AC XY:

AN XY:

74292

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:

0.0000588

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000523

Hom.:

Bravo

AF:

0.0000189

ExAC

AF:

0.00000824

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:7

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Microcephaly, normal intelligence and immunodeficiency

Uncertain:3

Jul 03, 2021

Natera, Inc.

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Nov 12, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces alanine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 183 of the NBN protein (p.Ala183Thr). This variant is present in population databases (rs151070415, gnomAD 0.01%). This missense change has been observed in individual(s) with breast cancer (PMID: 31512090). ClinVar contains an entry for this variant (Variation ID: 411786). An algorithm developed to predict the effect of missense changes on protein structure and function outputs the following: PolyPhen-2: "Benign". The threonine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect 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. -

Nov 07, 2021

Genome-Nilou Lab

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

not provided

Uncertain:3

Oct 06, 2016

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

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: The NBN c.547G>A (p.Ala183Thr) variant indicated to be located at the last amino position of the BRCT domain (via InterPro) causes a missense change involving a conserved nucleotide with 4/4 in silico tools (SNPs&GO not captured here due to low reliability index) predict a damaging outcome, although these predictions have yet to be functionally assessed. The variant of interest was observed in the large, broad control population, ExAC, with an allele frequency of 1/121276, which does not exceed the estimated maximal expected allele frequency for a pathogenic NBN variant of 1/400. The variant of interest has not, to our knowledge, been reported in affected individuals via publications and/or reputable databases/clinical diagnostic laboratories. Therefore, until additional information becomes available (ie, clinical and/or functional studies), the variant of interest has been classified as a "Variant of Uncertain Significance." -

Mar 17, 2023

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Observed in an individual with breast cancer (Scarpitta et al., 2019); This variant is associated with the following publications: (PMID: 24894818, 16188882, 34072463, 31512090) -

Jan 17, 2024

Quest Diagnostics Nichols Institute San Juan Capistrano

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The NBN c.547G>A (p.Ala183Thr) variant has been reported in the published literature in individuals with male breast cancer (PMID: 31512090 (2019)) and breast cancer (PMID: 33471991 (2021), see also LOVD (http://databases.lovd.nl/shared/genes/NBN)). This variant has also been identified in reportedly healthy individuals (PMID: 33471991 (2021), see also LOVD (http://databases.lovd.nl/shared/genes/NBN)). The frequency of this variant in the general population, 0.000026 (3/113650 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 damaging. Based on the available information, we are unable to determine the clinical significance of this variant. -

Hereditary cancer-predisposing syndrome

Uncertain:1

Jan 12, 2023

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.A183T variant (also known as c.547G>A), located in coding exon 5 of the NBN gene, results from a G to A substitution at nucleotide position 547. The alanine at codon 183 is replaced by threonine, an amino acid with similar properties. This variant has been reported in 1/81 male breast cancer patients who had multi-gene panel testing (Scarpitta R et al. Breast Cancer Res Treat, 2019 Dec;178:557-564). This amino acid position is 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. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.27

BayesDel_addAF

Benign

-0.056

BayesDel_noAF

Benign

-0.26

CADD

Uncertain

DANN

Pathogenic

1.0

DEOGEN2

Uncertain

0.42

T;T;.

Eigen

Uncertain

0.67

Eigen_PC

Uncertain

0.63

FATHMM_MKL

Uncertain

0.90

LIST_S2

Benign

0.78

T;T;T

M_CAP

Benign

0.020

MetaRNN

Benign

0.34

T;T;T

MetaSVM

Benign

-0.38

MutationAssessor

Pathogenic

2.9

M;.;.

PrimateAI

Benign

0.44

PROVEAN

Uncertain

-2.6

D;D;D

REVEL

Uncertain

0.30

Sift

Pathogenic

0.0

D;D;D

Sift4G

Uncertain

0.018

D;D;.

Polyphen

1.0

D;.;.

Vest4

0.42

MVP

0.77

MPC

0.12

ClinPred

0.94

GERP RS

5.1

Varity_R

0.62

gMVP

0.65

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