rs786202879

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 0P and 0B.

The NM_002485.5(NBN):​c.683T>G​(p.Ile228Arg) variant causes a missense change. The variant allele was found at a frequency of 0.0000794 in 1,612,876 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. I228V) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000039 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000084 ( 0 hom. )

Consequence

NBN
NM_002485.5 missense

Scores

3
12
4

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:12

Conservation

PhyloP100: 7.08

Publications

3 publications found
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 Gene-Disease associations (from GenCC):
  • Nijmegen breakage syndrome
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: G2P, Orphanet, Labcorp Genetics (formerly Invitae), ClinGen, Myriad Women’s Health
  • rhabdomyosarcoma
    Inheritance: AR Classification: MODERATE Submitted by: Genomics England PanelApp
  • idiopathic aplastic anemia
    Inheritance: AD Classification: LIMITED Submitted by: Labcorp Genetics (formerly Invitae)
  • prostate cancer
    Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics
  • hereditary breast carcinoma
    Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
NBNNM_002485.5 linkc.683T>G p.Ile228Arg missense_variant Exon 6 of 16 ENST00000265433.8 NP_002476.2 O60934

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
NBNENST00000265433.8 linkc.683T>G p.Ile228Arg missense_variant Exon 6 of 16 1 NM_002485.5 ENSP00000265433.4 O60934

Frequencies

GnomAD3 genomes
AF:
0.0000394
AC:
6
AN:
152222
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000241
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:
0.0000941
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000588
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000679
AC:
17
AN:
250470
AF XY:
0.0000591
show subpopulations
Gnomad AFR exome
AF:
0.0000619
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.000139
Gnomad NFE exome
AF:
0.000115
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000835
AC:
122
AN:
1460654
Hom.:
0
Cov.:
30
AF XY:
0.0000757
AC XY:
55
AN XY:
726634
show subpopulations
African (AFR)
AF:
0.0000299
AC:
1
AN:
33420
American (AMR)
AF:
0.00
AC:
0
AN:
44664
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26100
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39584
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86234
European-Finnish (FIN)
AF:
0.000150
AC:
8
AN:
53278
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5750
European-Non Finnish (NFE)
AF:
0.0000990
AC:
110
AN:
1111310
Other (OTH)
AF:
0.0000497
AC:
3
AN:
60314
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.485
Heterozygous variant carriers
0
7
14
21
28
35
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
10
20
30
40
50
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.0000394
AC:
6
AN:
152222
Hom.:
0
Cov.:
33
AF XY:
0.0000538
AC XY:
4
AN XY:
74368
show subpopulations
African (AFR)
AF:
0.0000241
AC:
1
AN:
41454
American (AMR)
AF:
0.00
AC:
0
AN:
15278
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5202
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4836
European-Finnish (FIN)
AF:
0.0000941
AC:
1
AN:
10628
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000588
AC:
4
AN:
68040
Other (OTH)
AF:
0.00
AC:
0
AN:
2088
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.517
Heterozygous variant carriers
0
1
2
2
3
4
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.000107
Hom.:
0
Bravo
AF:
0.0000264
ExAC
AF:
0.0000824
AC:
10
EpiCase
AF:
0.00
EpiControl
AF:
0.0000593

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:12
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Microcephaly, normal intelligence and immunodeficiency Uncertain:3
Oct 25, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces isoleucine, which is neutral and non-polar, with arginine, which is basic and polar, at codon 228 of the NBN protein (p.Ile228Arg). This variant is present in population databases (rs777460725, gnomAD 0.01%). This missense change has been observed in individual(s) with Lynch syndrome (PMID: 25980754). This missense change has been observed to co-occur in individuals with a different variant in NBN that has been determined to be pathogenic (Invitae), but the significance of this finding is unclear. ClinVar contains an entry for this variant (Variation ID: 186350). Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). 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. -

Sep 16, 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

- -

not provided Uncertain:3
Aug 22, 2019
ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The NBN c.683T>G, p.(Ile228Arg) variant (rs777460725), to our knowledge, is not reported in the medical literature but is reported in ClinVar (Variation ID: 186350). This variant is listed in the Genome Aggregation Database (gnomAD) with an overall population frequency of 0.007 percent (identified on 20 out of 281,876 chromosomes). The isoleucine at position 228 is weakly conserved and computational analyses of the effects of the p.(Ile228Arg) variant on protein structure and function is deleterious (SIFT: damaging, PolyPhen-2: possibly damaging). Altogether, there is not enough evidence to classify the p.(Ile228Arg) variant with certainty. -

May 10, 2024
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Published functional studies demonstrate loss of protein stability and sensitivity to mitomycin-C similar to a positive control (PMID: 37503171); Observed in individuals with breast cancer, Lynch-syndrome associated cancer and/or polyps, or B-cell acute lymphoblastic leukemia (PMID: 33471991, 25980754, 37503171); This variant is associated with the following publications: (PMID: 33471991, 25980754, 24894818, 37503171, 36346689, 38446568) -

Jan 18, 2024
Quest Diagnostics Nichols Institute San Juan Capistrano
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The NBN c.683T>G (p.Ile228Arg) variant has been reported in the published literature in an individual suspected of Lynch Syndrome (PMID: 25980754 (2015)). In a large-scale breast cancer association study, the variant was observed in individuals with breast cancer as well as in reportedly healthy individual (PMID: 33471991 (2021), see also LOVD (http://databases.lovd.nl/shared/genes/NBN)). The frequency of this variant in the general population, 0.00012 (16/128596 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 conflicting predictions that this variant is benign or damaging. Based on the available information, we are unable to determine the clinical significance of this variant. -

Hereditary cancer-predisposing syndrome Uncertain:2
Jun 01, 2021
Sema4, Sema4
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:curation

- -

May 10, 2023
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.I228R variant (also known as c.683T>G), located in coding exon 6 of the NBN gene, results from a T to G substitution at nucleotide position 683. The isoleucine at codon 228 is replaced by arginine, an amino acid with similar properties. This amino acid position is poorly conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Aplastic anemia;C0023449:Acute lymphoid leukemia;C0398791:Microcephaly, normal intelligence and immunodeficiency Uncertain:1
Oct 31, 2018
Fulgent Genetics, Fulgent Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not specified Uncertain:1
Mar 28, 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.683T>G (p.Ile228Arg) results in a non-conservative amino acid change located in the Nibrin, second BRCT domain of the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 6.5e-05 in 276394 control chromosomes (gnomAD). This frequency is not significantly higher than expected for a pathogenic variant in NBN causing Nijmegen Breakage Syndrome (6.5e-05 vs 0.0025), allowing no conclusion about variant significance. The variant, c.683T>G, has been reported in the literature in an individual being tested for Lynch Syndrome (Yurgelun_2015). These 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. Four 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
Feb 04, 2024
Baylor Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

NBN-related disorder Uncertain:1
Sep 11, 2024
PreventionGenetics, part of Exact Sciences
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:clinical testing

The NBN c.683T>G variant is predicted to result in the amino acid substitution p.Ile228Arg. This variant has been reported as a variant of uncertain significance in an individual undergoing testing for Lynch syndrome (Table S2, Yurgelun et al. 2015. PubMed ID: 25980754). This variant has also been reported as a variant of uncertain significance in a study of NBN as a pan-cancer susceptibility gene (Table S2, Belhadj et al. 2023. PubMed ID: 36346689). This variant is reported in 0.012% of alleles in individuals of European (Non-Finnish) descent in gnomAD and has been interpreted as a variant of uncertain significance in the ClinVar database (https://www.ncbi.nlm.nih.gov/clinvar/variation/186350/). 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
Pathogenic
0.85
BayesDel_addAF
Uncertain
0.073
D
BayesDel_noAF
Uncertain
0.070
CADD
Uncertain
25
DANN
Uncertain
0.98
DEOGEN2
Uncertain
0.44
T;T;.;.
Eigen
Uncertain
0.55
Eigen_PC
Uncertain
0.62
FATHMM_MKL
Pathogenic
0.97
D
LIST_S2
Uncertain
0.90
D;T;D;D
M_CAP
Benign
0.063
D
MetaRNN
Uncertain
0.56
D;D;D;D
MetaSVM
Uncertain
-0.25
T
MutationAssessor
Benign
2.0
M;.;.;.
PhyloP100
7.1
PrimateAI
Benign
0.34
T
PROVEAN
Pathogenic
-5.0
D;D;D;D
REVEL
Uncertain
0.54
Sift
Uncertain
0.0010
D;D;D;D
Sift4G
Uncertain
0.0030
D;D;D;.
Polyphen
0.95
P;.;.;.
Vest4
0.68
MutPred
0.69
Gain of disorder (P = 0.012);.;.;.;
MVP
0.92
MPC
0.34
ClinPred
0.43
T
GERP RS
5.8
Varity_R
0.77
gMVP
0.87
Mutation Taster
=63/37
polymorphism

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

Other links and lift over

dbSNP: rs777460725; hg19: chr8-90983420; API