8-89980758-C-T
Variant summary
Our verdict is Likely benign. Variant got -1 ACMG points: 0P and 1B. BP6
The NM_002485.5(NBN):c.456G>A(p.Met152Ile) variant causes a missense change. The variant allele was found at a frequency of 0.000234 in 1,612,958 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).
Frequency
Consequence
NM_002485.5 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Likely_benign. Variant got -1 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.000145 AC: 22AN: 152000Hom.: 0 Cov.: 32
GnomAD3 exomes AF: 0.000115 AC: 29AN: 251220Hom.: 0 AF XY: 0.000118 AC XY: 16AN XY: 135784
GnomAD4 exome AF: 0.000244 AC: 356AN: 1460840Hom.: 0 Cov.: 31 AF XY: 0.000256 AC XY: 186AN XY: 726810
GnomAD4 genome AF: 0.000145 AC: 22AN: 152118Hom.: 0 Cov.: 32 AF XY: 0.000161 AC XY: 12AN XY: 74360
ClinVar
Submissions by phenotype
Microcephaly, normal intelligence and immunodeficiency Uncertain:5Benign:1
The NBN c.456G>A (p.Met152Ile) missense change has a maximum subpopulation frequency of 0.019% in gnomAD v2.1.1 (https://gnomad.broadinstitute.org/). In silico tools are inconclusive about the effect of this variant on protein function, and to our knowledge functional assays have not been performed. This variant has been reported in individuals with breast cancer, ovarian cancer, prostate cancer, colorectal cancer, and suspected Lynch syndrome (PMID: 25980754, 26315354, 27978560, 28135145, 28528518, 30306255, 32832836, 32885271), as well as in women older than 70 years of age who have never had cancer (https://whi.color.com/). To our knowledge, this variant has not been reported in individuals with Nijmegen breakage syndrome. In summary, the evidence currently available is insufficient to determine the clinical significance of this variant. It has therefore been classified as of uncertain significance. -
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This variant was determined to be of uncertain significance according to ACMG Guidelines, 2015 [PMID:25741868]. -
This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). Publications were found based on this search. However, the evidence from the literature, in combination with allele frequency data from public databases where available, was not sufficient to rule this variant in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. -
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not provided Uncertain:4Other:2
The NBN c.456G>A (p.Met152Ile) variant has been reported in the published literature in individuals affected with breast and/or ovarian cancer (PMID: 34326862 (2021), 33471991 (2021), see also LOVD (https://databases.lovd.nl/shared/variants/NBN), 32885271 (2021), 30306255 (2018), 28528518 (2017), 26315354 (2015), 24894818 (2014), 23555315 (2013)), colorectal cancer (PMID: 27978560 (2016)), soft tissue sarcoma (PMID: 30541756 (2019)), and a myeloid malignancy (PMID: 31911633 (2020)). This variant has also been identified in reportedly healthy individuals (PMID: 33471991 (2021), see also LOVD (https://databases.lovd.nl/shared/variants/NBN)). The frequency of this variant in the general population, 0.00034 (17/50746 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. -
GenomeConnect assertions are reported exactly as they appear on the patient-provided report from the testing laboratory. GenomeConnect staff make no attempt to reinterpret the clinical significance of the variant. -
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In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; In silico analysis is inconclusive as to whether the variant alters gene splicing. In the absence of RNA/functional studies, the actual effect of this sequence change is unknown.; Observed in individuals with a personal or family history including breast, ovarian, colorectal, and other cancers (PMID: 23555315, 25980754, 26315354, 27978560, 28135145, 28528518); This variant is associated with the following publications: (PMID: 25980754, 26787654, 26315354, 23555315, 27978560, 28528518, 28135145, 30306255, 31874108, 33095795, 24894818, 34326862, 36346689, 37503171) -
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Variant reported in multiple Invitae PIN participants by multiple clinical testing laboratories. Variant interpreted as Variant of Uncertain Significance by all laboratories and reported most recently on 3/23/2020 by Invitae and 3/4/2017 by GeneDx. GenomeConnect-Invitae Patient Insights Network assertions are reported exactly as they appear on the patient-provided report from the testing laboratory. Registry team members make no attempt to reinterpret the clinical significance of the variant. Phenotypic details are available under supporting information. -
Hereditary cancer-predisposing syndrome Uncertain:2Benign:1
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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. -
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Aplastic anemia;C0023449:Acute lymphoid leukemia;C0398791:Microcephaly, normal intelligence and immunodeficiency Uncertain:1
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Aplastic anemia Uncertain:1
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Malignant tumor of breast Uncertain:1
The NBN p.Met152Ile variant was identified in 4 of 10048 proband chromosomes (frequency: 0.0004) from individuals or families with colon, breast or ovarian cancer and was not identified in 6862 control chromosomes from healthy individuals (Cock-Rada 2018, Pearlman 2016, Ramus 2015, Yurgelun 2015). The variant was also identified in dbSNP (ID: rs201816949) as "With Uncertain significance allele", and in ClinVar (classified as uncertain significance by Invitae, Ambry Genetics and five other submitters ). The variant was not identified in LOVD 3.0. The variant was identified in control databases in 34 of 276952 chromosomes at a frequency of 0.0001 increasing the likelihood this could be a low frequency benign variant (Genome Aggregation Database Feb 27, 2017). The variant was observed in the following populations: African in 2 of 24016 chromosomes (freq: 0.00008), Other in 1 of 6454 chromosomes (freq: 0.0002), Latino in 2 of 34410 chromosomes (freq: 0.00006), European in 28 of 126568 chromosomes (freq: 0.0002), Finnish in 1 of 25714 chromosomes (freq: 0.00004), while the variant was not observed in the Ashkenazi Jewish, East Asian, and South Asian populations. The p.Met152 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 2 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. -
not specified Benign:1
Variant summary: NBN c.456G>A (p.Met152Ile) results in a conservative amino acid change located in the BRCT domain of 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 0.00012 in 251220 control chromosomes, predominantly at a frequency of 0.00019 within the Non-Finnish European subpopulation in the gnomAD database. The observed variant frequency within Non-Finnish European control individuals in the gnomAD database is approximately 1.5 fold of the estimated maximal expected allele frequency for a pathogenic variant in NBN causing Hereditary Breast And Ovarian Cancer Syndrome phenotype (0.00013), strongly suggesting that the variant is a benign polymorphism found primarily in populations of Non-Finnish European origin. In addition, one database reported this variant was found in seven women older than age 70 years who have never had cancer. c.456G>A has been reported in the literature in individuals affected with breast and ovarian cancer, primary ovarian insufficiency, colon cancer and/or polyps, or prostate cancer (Ramus_2015, Yurgelun_2015, Pearlman_2016, Cock-Rada_2017, Bonache_2018, Franca_2020, Mateo_2020). These reports do not provide unequivocal conclusions about association of the variant with Hereditary Breast and Ovarian Cancer. At-least one co-occurrence with a BRCA2 pathogenic variant has been observed at our laboratory (c.5864C>A, p.Ser1955X), providing supporting evidence for a benign role. 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: 30306255, 28528518, 33095795, 31874108, 27978560, 26315354, 25980754). Multiple clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation (VUS n=12, likely benign n=3). Based on the evidence outlined above, the variant was classified as likely benign. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at