8-89982829-C-T
Variant summary
Our verdict is Likely benign. The variant received -2 ACMG points: 0P and 2B. BP4_Moderate
The NM_002485.5(NBN):c.64G>A(p.Val22Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000496 in 1,613,368 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/22 in silico tools predict a benign outcome for this variant. 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. V22F) has been classified as Likely benign.
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.
Variant Effect in Transcripts
ACMG analysis was done for transcript: NM_002485.5. You can select a different transcript below to see updated ACMG assignments.
RefSeq Transcripts
| Selected | Gene | Transcript | Tags | HGVSc | HGVSp | Effect | Exon Rank | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|---|
| NBN | NM_002485.5 | MANE Select | c.64G>A | p.Val22Ile | missense | Exon 2 of 16 | NP_002476.2 | ||
| NBN | NM_001024688.3 | c.-233G>A | 5_prime_UTR | Exon 2 of 17 | NP_001019859.1 | ||||
| NBN | NM_001440379.1 | c.-183G>A | 5_prime_UTR | Exon 2 of 16 | NP_001427308.1 |
Ensembl Transcripts
| Selected | Gene | Transcript | Tags | HGVSc | HGVSp | Effect | Exon Rank | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|---|
| NBN | ENST00000265433.8 | TSL:1 MANE Select | c.64G>A | p.Val22Ile | missense | Exon 2 of 16 | ENSP00000265433.4 | ||
| NBN | ENST00000697309.1 | c.64G>A | p.Val22Ile | missense | Exon 2 of 15 | ENSP00000513244.1 | |||
| NBN | ENST00000697293.1 | c.64G>A | p.Val22Ile | missense | Exon 2 of 17 | ENSP00000513230.1 |
Frequencies
GnomAD3 genomes AF: 0.00000658 AC: 1AN: 152060Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.00000398 AC: 1AN: 251348 AF XY: 0.00000736 show subpopulations
GnomAD4 exome AF: 0.00000479 AC: 7AN: 1461308Hom.: 0 Cov.: 31 AF XY: 0.00000963 AC XY: 7AN XY: 726982 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.00000658 AC: 1AN: 152060Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0AN XY: 74268 show subpopulations
ClinVar
Submissions by phenotype
Microcephaly, normal intelligence and immunodeficiency Uncertain:3
This sequence change replaces valine, which is neutral and non-polar, with isoleucine, which is neutral and non-polar, at codon 22 of the NBN protein (p.Val22Ile). This variant is present in population databases (rs369910645, gnomAD 0.002%). 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: 239202). Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Not Available"; PolyPhen-2: "Benign"; Align-GVGD: "Not Available". The isoleucine 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.
NBN-related disorder Uncertain:1
The NBN c.64G>A variant is predicted to result in the amino acid substitution p.Val22Ile. To our knowledge, this variant has not been reported in the literature. This variant is reported in 0.00088% of alleles in individuals of European (Non-Finnish) descent in gnomAD and is interpreted as uncertain in ClinVar (https://www.ncbi.nlm.nih.gov/clinvar/variation/239202/). 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
The p.V22I variant (also known as c.64G>A), located in coding exon 2 of the NBN gene, results from a G to A substitution at nucleotide position 64. The valine at codon 22 is replaced by isoleucine, an amino acid with highly similar properties. This variant was reported in 1/60,466 breast cancer cases and in 1/53,461 controls (Dorling et al. N Engl J Med. 2021 02;384:428-439). 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:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at