8-89953624-G-C
Variant summary
Our verdict is Likely benign. Variant got -5 ACMG points: 0P and 5B. BP4_StrongBP6
The NM_002485.5(NBN):āc.1465C>Gā(p.Leu489Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000868 in 1,612,548 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).
Frequency
Consequence
NM_002485.5 missense
Scores
Clinical Significance
Conservation
Genome browser will be placed here
ACMG classification
Verdict is Likely_benign. Variant got -5 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.00000658 AC: 1AN: 151960Hom.: 0 Cov.: 32
GnomAD3 exomes AF: 0.0000200 AC: 5AN: 250592Hom.: 0 AF XY: 0.0000148 AC XY: 2AN XY: 135482
GnomAD4 exome AF: 0.00000890 AC: 13AN: 1460588Hom.: 0 Cov.: 32 AF XY: 0.00000826 AC XY: 6AN XY: 726648
GnomAD4 genome AF: 0.00000658 AC: 1AN: 151960Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0AN XY: 74210
ClinVar
Submissions by phenotype
Microcephaly, normal intelligence and immunodeficiency Uncertain:2Benign:1
- -
- -
This sequence change replaces leucine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 489 of the NBN protein (p.Leu489Val). This variant is present in population databases (rs143948240, gnomAD 0.03%). This missense change has been observed in individual(s) with colorectal cancer (PMID: 28135145). ClinVar contains an entry for this variant (Variation ID: 184816). 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 valine 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. -
Hereditary cancer-predisposing syndrome Uncertain:2Benign: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. -
- -
- -
Aplastic anemia Uncertain:1
- -
Malignant tumor of breast Uncertain:1
The NBN p.Leu489Val variant was identified in 1 of 2116 proband chromosomes (frequency: 0.0005) from individuals or families with colorectal cancer (Yurgelun 2017). The variant was also identified in dbSNP (ID: rs143948240) as "With other allele", ClinVar (classified as likely benign by Ambry Genetics; as uncertain significance by Invitae, Color, and Counsyl). The variant was not identified in LOVD 3.0 database. The variant was identified in 3 of 245400 chromosomes at a frequency of 0.00001 (Genome Aggregation Database Feb 27, 2017). It was observed in the Ashkenazi Jewish population in 3 of 9836 chromosomes (freq: 0.0003), but not in the African, Other, Latino, European, East Asian, European Finnish, or South Asian populations. The p.Leu489 residue is conserved in mammals but not in more distantly related organisms however four out of five computational analyses (PolyPhen-2, SIFT, AlignGVGD, BLOSUM, MutationTaster) do not suggest a high likelihood of impact to the protein; this information is not predictive enough to rule out pathogenicity. The variant occurs outside of the splicing consensus sequence and in silico or computational prediction software programs (SpliceSiteFinder, MaxEntScan, NNSPLICE, GeneSplicer) do not predict a difference in splicing. 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