Genetic Variant NM_002485.5:c.2149A>T (chr8-89943288-T-A) – ACMG Classification: Likely_benign (-2 pts)

Variant summary

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

The NM_002485.5(NBN):c.2149A>T(p.Thr717Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000558 in 1,613,684 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 (★★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000055 ( 0 hom. )

Consequence

NBN
NM_002485.5 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:11

Conservation

PhyloP100: 0.139

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 -2 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.07264182).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
NBN	NM_002485.5 link	c.2149A>T	p.Thr717Ser	missense_variant	Exon 14 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.2149A>T	p.Thr717Ser	missense_variant	Exon 14 of 16	1	NM_002485.5	ENSP00000265433.4		O60934

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152184

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:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD4 exome

AF:

0.00000547

AC:

AN:

1461500

Hom.:

Cov.:

AF XY:

0.00000688

AC XY:

AN XY:

727060

show subpopulations

Gnomad4 AFR exome

AF:

0.00

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:

0.00000360

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152184

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74350

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:

0.0000147

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.00000756

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:11

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Microcephaly, normal intelligence and immunodeficiency

Uncertain:4

Nov 07, 2021

Genome-Nilou Lab

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Jan 29, 2020

Natera, Inc.

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Nov 27, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces threonine, which is neutral and polar, with serine, which is neutral and polar, at codon 717 of the NBN protein (p.Thr717Ser). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with clinical features of NBN-related conditions (PMID: 31159747). ClinVar contains an entry for this variant (Variation ID: 127865). 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 tolerated. 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. -

May 28, 2019

Mendelics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

not specified

Uncertain:2

Sep 12, 2017

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.2149A>T (p.Thr717Ser) variant located in the DNA repair Nbs1, C-terminal domain (via InterPro) involves the alteration of a non-conserved nucleotide and 5/5 in silico tools predict a benign outcome for this variant. However, these predictions have yet to be functionally assessed. This variant is absent in 121388 control chromosomes and has not, to our knowledge been reported in affected indivduals in the literature. In addition, multiple clinical diagnostic laboratories/reputable databases classified this variant as uncertain significance. Because of the absence of clinical information and the lack of functional studies, the variant is classified as a "Variant of Uncertain Significance (VUS)," until additional information becomes available. -

Jun 11, 2021

Genetic Services Laboratory, University of Chicago

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

DNA sequence analysis of the NBN gene demonstrated a sequence change, c.2149A>T, in exon 14 that results in an amino acid change, p.Thr717Ser. This sequence change has not been described in the gnomAD database. The p.Thr717Ser change affects a poorly conserved amino acid residue located in a domain of the NBN protein that is known to be functional. The p.Thr717Ser substitution appears to be benign using several in-silico pathogenicity prediction tools (SIFT, PolyPhen2, Align GVGD, REVEL). This sequence change has been reported as a variant of uncertain significance in an individual who underwent germline genetic testing based on a personal and/or family history of cancer (PMID: 31159747). Due to insufficient evidences and the lack of functional studies, the clinical significance of the p.Thr717Ser change remains unknown at this time. -

not provided

Uncertain:2

Mar 18, 2022

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Not observed in large population cohorts (gnomAD); In silico analysis supports that this missense variant does not alter protein structure/function; Observed in an individual with breast cancer (Hauke 2018); This variant is associated with the following publications: (PMID: 29522266, 31159747) -

Breakthrough Genomics, Breakthrough Genomics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: not provided

- -

Hereditary cancer-predisposing syndrome

Uncertain:2

Jan 11, 2023

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.T717S variant (also known as c.2149A>T), located in coding exon 14 of the NBN gene, results from an A to T substitution at nucleotide position 2149. The threonine at codon 717 is replaced by serine, an amino acid with similar properties. This alteration was detected in 1/5589 German BRCA1/2-negative probands with breast cancer (Hauke J et al. Cancer Med, 2018 04;7:1349-1358), as well as 1/1197 individuals from Greece, Romania, and Turkey undergoing evaluation for inherited cancer predisposition (Tsaousis GN et al. BMC Cancer, 2019 Jun;19:535). 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. -

Aug 01, 2018

GeneKor MSA

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Aplastic anemia;C0023449:Acute lymphoid leukemia;C0398791:Microcephaly, normal intelligence and immunodeficiency

Uncertain:1

May 23, 2017

Fulgent Genetics, Fulgent Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.095

BayesDel_addAF

Benign

-0.31

BayesDel_noAF

Benign

-0.68

CADD

Benign

7.9

DANN

Benign

0.62

DEOGEN2

Benign

0.053

T;T;.

Eigen

Benign

-1.0

Eigen_PC

Benign

-0.91

FATHMM_MKL

Benign

0.49

LIST_S2

Benign

0.68

T;T;T

M_CAP

Benign

0.011

MetaRNN

Benign

0.073

T;T;T

MetaSVM

Benign

-1.0

MutationAssessor

Benign

-1.1

N;.;.

PrimateAI

Benign

0.32

PROVEAN

Benign

0.61

N;N;.

REVEL

Benign

0.015

Sift

Benign

0.88

T;T;.

Sift4G

Benign

1.0

T;T;T

Polyphen

0.0030

B;.;.

Vest4

0.069

MutPred

0.36

Gain of loop (P = 0.0045);.;.;

MVP

0.35

MPC

0.063

ClinPred

0.057

GERP RS

-0.70

Varity_R

0.028

gMVP

0.067

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