chr8-89937034-A-T

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_002485.5(NBN):​c.2226T>A​(p.Asp742Glu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000031 in 1,610,586 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000021 ( 0 hom. )

Consequence

NBN
NM_002485.5 missense

Scores

3
5
11

Clinical Significance

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

Conservation

PhyloP100: 0.269
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 Uncertain_significance. Variant got 2 ACMG points.

PM2
Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE Protein UniProt
NBNNM_002485.5 linkuse as main transcriptc.2226T>A p.Asp742Glu missense_variant 15/16 ENST00000265433.8 NP_002476.2 O60934

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
NBNENST00000265433.8 linkuse as main transcriptc.2226T>A p.Asp742Glu missense_variant 15/161 NM_002485.5 ENSP00000265433.4 O60934

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152204
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000482
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:
0.0000160
AC:
4
AN:
249956
Hom.:
0
AF XY:
0.0000222
AC XY:
3
AN XY:
135112
show subpopulations
Gnomad AFR exome
AF:
0.000188
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:
0.00000884
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000206
AC:
3
AN:
1458382
Hom.:
0
Cov.:
29
AF XY:
0.00000276
AC XY:
2
AN XY:
725728
show subpopulations
Gnomad4 AFR exome
AF:
0.0000898
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:
0.00
GnomAD4 genome
AF:
0.0000131
AC:
2
AN:
152204
Hom.:
0
Cov.:
32
AF XY:
0.0000134
AC XY:
1
AN XY:
74364
show subpopulations
Gnomad4 AFR
AF:
0.0000482
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
Bravo
AF:
0.00000756
ExAC
AF:
0.0000165
AC:
2
EpiCase
AF:
0.00
EpiControl
AF:
0.0000593

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
Uncertain significance, no assertion criteria providedclinical testingNatera, Inc.May 04, 2021- -
Uncertain significance, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpAug 24, 2022This sequence change replaces aspartic acid, which is acidic and polar, with glutamic acid, which is acidic and polar, at codon 742 of the NBN protein (p.Asp742Glu). This variant is present in population databases (rs767523514, gnomAD 0.02%). This variant has not been reported in the literature in individuals affected with NBN-related conditions. ClinVar contains an entry for this variant (Variation ID: 230832). Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Deleterious"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0". The glutamic acid 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. -
Uncertain significance, criteria provided, single submitterclinical testingGenome-Nilou LabNov 07, 2021- -
not specified Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingWomen's Health and Genetics/Laboratory Corporation of America, LabCorpMay 19, 2021Variant summary: NBN c.2226T>A (p.Asp742Glu) results in a conservative amino acid change located in the DNA repair Nbs1, C-terminal domain (IPR013908) 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 1.6e-05 in 249956 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. To our knowledge, no occurrence of c.2226T>A in individuals affected with Nijmegen Breakage Syndrome and no experimental evidence demonstrating its impact on protein function have been reported. Two ClinVar submitters (evaluation after 2014) have cited 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 submitterclinical testingBaylor GeneticsNov 02, 2023- -
not provided Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingQuest Diagnostics Nichols Institute San Juan CapistranoAug 26, 2024The NBN c.2226T>A (p.Asp742Glu) variant has been reported in the published literature in a cohort of individuals with unspecified cancer (PMID: 36346689 (2023)). The frequency of this variant in the general population, 0.00016 (4/24682 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:1
Uncertain significance, criteria provided, single submitterclinical testingAmbry GeneticsMar 31, 2024The p.D742E variant (also known as c.2226T>A), located in coding exon 15 of the NBN gene, results from a T to A substitution at nucleotide position 2226. The aspartic acid at codon 742 is replaced by glutamic acid, an amino acid with highly similar properties. This amino acid position is highly 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
Pathogenic
0.65
BayesDel_addAF
Benign
-0.16
T
BayesDel_noAF
Benign
-0.18
CADD
Benign
18
DANN
Uncertain
0.99
DEOGEN2
Benign
0.15
T;T;.
Eigen
Benign
-0.013
Eigen_PC
Benign
-0.13
FATHMM_MKL
Benign
0.71
D
LIST_S2
Benign
0.72
T;T;T
M_CAP
Benign
0.076
D
MetaRNN
Uncertain
0.43
T;T;T
MetaSVM
Benign
-0.43
T
MutationAssessor
Uncertain
2.6
M;.;.
PrimateAI
Uncertain
0.60
T
PROVEAN
Benign
-2.1
N;N;.
REVEL
Uncertain
0.46
Sift
Pathogenic
0.0
D;D;.
Sift4G
Pathogenic
0.0
D;D;D
Polyphen
1.0
D;.;.
Vest4
0.47
MutPred
0.71
Gain of loop (P = 0);.;.;
MVP
0.81
MPC
0.29
ClinPred
0.93
D
GERP RS
-3.0
Varity_R
0.50
gMVP
0.27

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.030
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: rs767523514; hg19: chr8-90949262; API