rs535602436

Variant summary

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

The NM_002485.5(NBN):​c.803C>T​(p.Thr268Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000403 in 1,613,912 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 0.000059 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000038 ( 0 hom. )

Consequence

NBN
NM_002485.5 missense

Scores

1
18

Clinical Significance

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

Conservation

PhyloP100: 0.474
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]

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=0.24264103).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
NBNNM_002485.5 linkc.803C>T p.Thr268Met missense_variant Exon 7 of 16 ENST00000265433.8 NP_002476.2 O60934

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
NBNENST00000265433.8 linkc.803C>T p.Thr268Met missense_variant Exon 7 of 16 1 NM_002485.5 ENSP00000265433.4 O60934

Frequencies

GnomAD3 genomes
AF:
0.0000592
AC:
9
AN:
152112
Hom.:
0
Cov.:
32
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:
0.000192
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.000118
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.0000358
AC:
9
AN:
251296
Hom.:
0
AF XY:
0.0000221
AC XY:
3
AN XY:
135814
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000289
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:
0.0000704
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000383
AC:
56
AN:
1461682
Hom.:
0
Cov.:
31
AF XY:
0.0000358
AC XY:
26
AN XY:
727148
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.0000447
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.0000252
Gnomad4 SAS exome
AF:
0.0000116
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.0000441
Gnomad4 OTH exome
AF:
0.0000497
GnomAD4 genome
AF:
0.0000591
AC:
9
AN:
152230
Hom.:
0
Cov.:
32
AF XY:
0.0000269
AC XY:
2
AN XY:
74436
show subpopulations
Gnomad4 AFR
AF:
0.00
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.000193
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.000118
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.0000959
Hom.:
0
Bravo
AF:
0.0000567
TwinsUK
AF:
0.000270
AC:
1
ALSPAC
AF:
0.00
AC:
0
ExAC
AF:
0.0000494
AC:
6
EpiCase
AF:
0.000109
EpiControl
AF:
0.000119

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
Feb 14, 2020
Natera, Inc.
Significance: Uncertain significance
Review Status: no assertion criteria provided
Collection Method: clinical testing

- -

Nov 07, 2021
Genome-Nilou Lab
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Jul 02, 2018
Mendelics
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Nov 06, 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 methionine, which is neutral and non-polar, at codon 268 of the NBN protein (p.Thr268Met). This variant is present in population databases (rs535602436, gnomAD 0.007%). This missense change has been observed in individual(s) with breast and/or ovarian cancer (PMID: 26315354, 29522266). ClinVar contains an entry for this variant (Variation ID: 182734). 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. -

not provided Uncertain:2
Mar 08, 2023
GeneDx
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

Observed in individuals with breast or ovarian cancer and in unaffected controls (Ramus et al., 2015; Hauke et al., 2018; Momozawa et al., 2018; Fujita et al., 2020); In silico analysis supports that this missense variant does not alter protein structure/function; This variant is associated with the following publications: (PMID: 26315354, 26644315, 29522266, 30287823, 33309985, 24894818) -

Nov 03, 2021
Institute for Clinical Genetics, University Hospital TU Dresden, University Hospital TU Dresden
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

not specified Uncertain:1
Jan 15, 2019
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: NBN c.803C>T (p.Thr268Met) results in a non-conservative amino acid change located in the Nibrin, second BRCT domain of the encoded protein sequence. Three of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 3.6e-05 in 277034 control chromosomes. This frequency is not significantly higher than expected for a pathogenic variant in NBN causing Nijmegen Breakage Syndrome (3.6e-05 vs 0.0025), allowing no conclusion about variant significance. c.803C>T has been reported in the literature in individuals affected with breast or ovarian cancer (Ramus_2015, Hauke_2018). These reports do not provide unequivocal conclusions about association of the variant with Nijmegen Breakage Syndrome or HBOC. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Five 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;C0023449:Acute lymphoid leukemia;C0398791:Microcephaly, normal intelligence and immunodeficiency Uncertain:1
Aug 10, 2021
Fulgent Genetics, Fulgent Genetics
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Aplastic anemia Uncertain:1
Mar 21, 2024
Baylor Genetics
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

NBN-related disorder Uncertain:1
Aug 09, 2024
PreventionGenetics, part of Exact Sciences
Significance: Uncertain significance
Review Status: no assertion criteria provided
Collection Method: clinical testing

The NBN c.803C>T variant is predicted to result in the amino acid substitution p.Thr268Met. This variant was reported in an individual with ovarian cancer (Ramus et al 2015. PubMed ID: 26315354). This variant is reported in 0.0070% of alleles in individuals of European (Non-Finnish) descent in gnomAD and is interpreted as a variant of uncertain significance in ClinVar (https://www.ncbi.nlm.nih.gov/clinvar/variation/182734/). At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -

Hereditary cancer-predisposing syndrome Uncertain:1
Dec 27, 2022
Ambry Genetics
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

The p.T268M variant (also known as c.803C>T), located in coding exon 7 of the NBN gene, results from a C to T substitution at nucleotide position 803. The threonine at codon 268 is replaced by methionine, an amino acid with similar properties. In one study, this alteration was observed in 5/3236 cases with invasive epithelial ovarian cancer and 0/3431 controls (Ramus SJ et al. J. Natl. Cancer Inst. 2015 Nov;107:). In another study, this alteration was not observed in 7051 unselected female breast cancer patients and was detected in 1/11241 female controls of Japanese ancestry (Momozawa Y et al. Nat Commun. 2018 10;9:4083). 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. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.10
BayesDel_addAF
Benign
-0.29
T
BayesDel_noAF
Benign
-0.47
CADD
Benign
18
DANN
Benign
0.97
DEOGEN2
Benign
0.24
T;T
Eigen
Benign
-0.12
Eigen_PC
Benign
-0.28
FATHMM_MKL
Benign
0.13
N
LIST_S2
Benign
0.74
T;T
M_CAP
Benign
0.027
D
MetaRNN
Benign
0.24
T;T
MetaSVM
Benign
-0.81
T
MutationAssessor
Benign
1.9
L;.
PrimateAI
Benign
0.27
T
PROVEAN
Benign
-2.2
N;N
REVEL
Benign
0.21
Sift
Benign
0.036
D;D
Sift4G
Uncertain
0.021
D;D
Polyphen
0.98
D;.
Vest4
0.29
MutPred
0.45
Loss of helix (P = 0.0104);.;
MVP
0.81
MPC
0.11
ClinPred
0.17
T
GERP RS
2.8
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.028
gMVP
0.57

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.15
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.

Other links and lift over

dbSNP: rs535602436; hg19: chr8-90982685; COSMIC: COSV55377232; COSMIC: COSV55377232; API