rs730881862
Variant summary
Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PP3_Moderate
The NM_002485.5(NBN):c.938C>T(p.Ala313Val) variant causes a missense change. The variant allele was found at a frequency of 0.0000168 in 1,611,886 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).
Frequency
Consequence
NM_002485.5 missense
Scores
Clinical Significance
Conservation
Genome browser will be placed here
ACMG classification
Verdict is Uncertain_significance. Variant got 2 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.00000658 AC: 1AN: 152084Hom.: 0 Cov.: 32
GnomAD3 exomes AF: 0.0000318 AC: 8AN: 251196Hom.: 0 AF XY: 0.0000442 AC XY: 6AN XY: 135744
GnomAD4 exome AF: 0.0000178 AC: 26AN: 1459802Hom.: 0 Cov.: 30 AF XY: 0.0000234 AC XY: 17AN XY: 726340
GnomAD4 genome AF: 0.00000658 AC: 1AN: 152084Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1AN XY: 74270
ClinVar
Submissions by phenotype
Microcephaly, normal intelligence and immunodeficiency Uncertain:3
- -
- -
This sequence change replaces alanine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 313 of the NBN protein (p.Ala313Val). This variant is present in population databases (rs730881862, gnomAD 0.01%). 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: 182735). 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 disruptive. 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. -
not provided Uncertain:2
In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 27149842, 24894818, 37503171, 36346689) -
- -
Hereditary cancer-predisposing syndrome Uncertain:2
- -
The c.938C>T (p.A313V) alteration is located in exon 8 (coding exon 8) of the NBN gene. This alteration results from a C to T substitution at nucleotide position 938, causing the alanine (A) at amino acid position 313 to be replaced by a valine (V). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -
not specified Uncertain:1
Variant summary: NBN c.938C>T (p.Ala313Val) results in a non-conservative amino acid change located in the Nibrin, second BRCT domain (IPR032429) of the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 3.2e-05 in 251196 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.938C>T has been reported in the literature in an study for screening cancer susceptibility variants (Belhadj_2023). 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 publication have been ascertained in the context of this evaluation (PMID: 36346689). ClinVar contains an entry for this variant (Variation ID: 182735). Based on the evidence outlined above, the variant was classified as uncertain significance. -
Aplastic anemia Uncertain:1
- -
Malignant tumor of breast Uncertain:1
The NBN p.Ala313Val variant was not identified in the literature nor was it identified in the LOVD 3.0, or Zhejiang University databases. The variant was also identified in dbSNP (ID: rs730881862) as "With Uncertain significance allele", ClinVar (classified as uncertain significance by GeneDx, Ambry Genetics, Invitae, Color and one clinical laboratory), and in Cosmic (1x Large intestine). The variant was identified in control databases in 9 of 245950 chromosomes at a frequency of 0.00004 (Genome Aggregation Database Feb 27, 2017). The variant was observed in the following populations: Latino in 5 of 33558 chromosomes (freq: 0.0002), European in 3 of 111480 chromosomes (freq: 0.00003), and South Asian in 1 of 30782 chromosomes (freq: 0.00003); it was not observed in the African, Other, Ashkenazi Jewish, East Asian, or Finnish populations. The p.Ala313 residue is conserved in mammals and computational analyses (PolyPhen-2, SIFT, AlignGVGD, BLOSUM, MutationTaster) provide inconsistent predictions regarding the impact to the protein; this information is not very predictive of pathogenicity. The variant occurs outside of the splicing consensus sequence and 1 of 4 in silico or computational prediction software programs (SpliceSiteFinder, MaxEntScan, NNSPLICE, GeneSplicer) predict a greater than 10% difference in splicing; this is not very predictive of pathogenicity. In summary, based on the above information the clinical significance of this variant cannot be determined with certainty at this time. This variant is classified as a variant of uncertain significance. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at