8-89958826-G-C
Variant summary
Our verdict is Likely benign. The variant received -2 ACMG points: 0P and 2B. BP4_Moderate
The NM_002485.5(NBN):c.1023C>G(p.Ser341Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000062 in 1,613,704 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. S341N) has been classified as Uncertain significance.
Frequency
Consequence
NM_002485.5 missense
Scores
Clinical Significance
Conservation
Publications
- Nijmegen breakage syndromeInheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: G2P, Orphanet, Labcorp Genetics (formerly Invitae), ClinGen, Myriad Women’s Health
- rhabdomyosarcomaInheritance: AR Classification: MODERATE Submitted by: Genomics England PanelApp
- idiopathic aplastic anemiaInheritance: AD Classification: LIMITED Submitted by: Labcorp Genetics (formerly Invitae)
- prostate cancerInheritance: AD Classification: LIMITED Submitted by: Ambry Genetics
- hereditary breast carcinomaInheritance: AD Classification: NO_KNOWN Submitted by: ClinGen
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ACMG classification
Our verdict: Likely_benign. The variant received -2 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| NBN | NM_002485.5 | c.1023C>G | p.Ser341Arg | missense_variant | Exon 9 of 16 | ENST00000265433.8 | NP_002476.2 |
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| NBN | ENST00000265433.8 | c.1023C>G | p.Ser341Arg | missense_variant | Exon 9 of 16 | 1 | NM_002485.5 | ENSP00000265433.4 |
Frequencies
GnomAD3 genomes AF: 0.0000131 AC: 2AN: 152184Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.0000477 AC: 12AN: 251372 AF XY: 0.0000368 show subpopulations
GnomAD4 exome AF: 0.00000547 AC: 8AN: 1461520Hom.: 0 Cov.: 32 AF XY: 0.00000550 AC XY: 4AN XY: 727104 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000131 AC: 2AN: 152184Hom.: 0 Cov.: 32 AF XY: 0.0000269 AC XY: 2AN XY: 74340 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
Microcephaly, normal intelligence and immunodeficiency Uncertain:4
This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -
This sequence change replaces serine, which is neutral and polar, with arginine, which is basic and polar, at codon 341 of the NBN protein (p.Ser341Arg). This variant is present in population databases (rs756023239, gnomAD 0.07%). This missense change has been observed in individual(s) with NBN-related cancer (PMID: 32068069, 36346689). ClinVar contains an entry for this variant (Variation ID: 239182). 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. -
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not specified Uncertain:2
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Variant summary: NBN c.1023C>G (p.Ser341Arg) results in a non-conservative amino acid change in 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 5e-05 in 262613 control chromosomes. c.1023C>G has been reported in the literature in individuals affected with breast cancer, epithelial ovarian cancer, or other unspecified cancer, without evidence of causality (e.g. Kwong_2020, Belhadj_2022, Yao_2022). These report(s) do 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. The following publications have been ascertained in the context of this evaluation (PMID: 36346689, 32068069, 30287823, 35186721). Seven submitters have cited clinical-significance assessments for this variant to ClinVar after 2014, classifying the variant as uncertain significance (n=6) or likely benign (n=1). Based on the evidence outlined above, the variant was classified as uncertain significance. -
not provided Uncertain:2
In silico analysis indicates that this missense variant does not alter protein structure/function; Observed in controls but absent from cases in a case-control study of breast cancer (PMID: 30287823); This variant is associated with the following publications: (PMID: 36346689, 30287823) -
In the published literature, this variant has been reported in individuals with breast cancer as well as unaffected individuals (PMID: 30287823 (2018), 33471991 (2021), see also LOVD (http://databases.lovd.nl/shared/genes/NBN)). The frequency of this variant in the general population, 0.0007 (14/19954 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. -
Aplastic anemia Uncertain:1
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Hereditary cancer-predisposing syndrome Benign:1
This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at