NM_002485.5:c.323T>C
Variant summary
Our verdict is Likely benign. The variant received -1 ACMG points: 0P and 1B. BP4
The NM_002485.5(NBN):c.323T>C(p.Ile108Thr) variant causes a missense, splice region change. The variant allele was found at a frequency of 0.00000558 in 1,612,054 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 1/1 splice prediction tools predict no significant impact on normal splicing. 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. I108V) has been classified as Likely benign.
Frequency
Consequence
NM_002485.5 missense, splice_region
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 -1 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.00000657 AC: 1AN: 152216Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.0000239 AC: 6AN: 250562 AF XY: 0.0000295 show subpopulations
GnomAD4 exome AF: 0.00000548 AC: 8AN: 1459838Hom.: 0 Cov.: 31 AF XY: 0.00000688 AC XY: 5AN XY: 726350 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.00000657 AC: 1AN: 152216Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0AN XY: 74354 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
Microcephaly, normal intelligence and immunodeficiency Uncertain:3
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This sequence change replaces isoleucine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 108 of the NBN protein (p.Ile108Thr). This variant is present in population databases (rs775217949, 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: 419525). 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: "Benign"; 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. -
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not provided Uncertain:1
This variant is denoted NBN c.323T>C at the cDNA level, p.Ile108Thr (I108T) at the protein level, and results in the change of an Isoleucine to a Threonine (ATA>ACA). This variant has not, to our knowledge, been published in the literature as pathogenic or benign. NBN Ile108Thr was not observed in approximately 6,500 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, indicating it is not a common benign variant in these populations. Since Isoleucine and Threonine differ in polarity, charge, size or other properties, this is considered a non-conservative amino acid substitution. NBN Ile108Thr occurs at a position where amino acids with properties similar to Isoleucine are tolerated across species and is located in the BRCT domain (Uniprot). In silico analyses are inconsistent regarding the effect this variant may have on protein structure and function. Based on currently available information, it is unclear whether NBN Ile108Thr is pathogenic or benign. We consider it to be a variant of uncertain significance. -
Hereditary cancer-predisposing syndrome Uncertain:1
The p.I108T variant (also known as c.323T>C), located in coding exon 4 of the NBN gene, results from a T to C substitution at nucleotide position 323. The isoleucine at codon 108 is replaced by threonine, 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. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at