rs142301194
Variant summary
Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PVS1PP5_Very_Strong
The NM_002485.5(NBN):c.2234+2T>G variant causes a splice donor, intron change. The variant allele was found at a frequency of 0.00000436 in 1,606,508 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★).
Frequency
Consequence
NM_002485.5 splice_donor, intron
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Pathogenic. Variant got 16 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.00000657 AC: 1AN: 152226Hom.: 0 Cov.: 32
GnomAD3 exomes AF: 0.00000801 AC: 2AN: 249784Hom.: 0 AF XY: 0.00000740 AC XY: 1AN XY: 135044
GnomAD4 exome AF: 0.00000413 AC: 6AN: 1454282Hom.: 0 Cov.: 28 AF XY: 0.00000553 AC XY: 4AN XY: 723910
GnomAD4 genome AF: 0.00000657 AC: 1AN: 152226Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0AN XY: 74370
ClinVar
Submissions by phenotype
not provided Pathogenic:2
Canonical splice site variant predicted to result in a null allele in a gene for which loss of function is a known mechanism of disease; Not observed at significant frequency in large population cohorts (gnomAD); Observed in individuals referred for hereditary cancer testing (LaDuca et al., 2017); This variant is associated with the following publications: (PMID: 23334666, 21035407, 17429352, 29922827, 24894818, 15964794, 15048089, 33804961, 28152038) -
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Hereditary cancer-predisposing syndrome Pathogenic:2
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The c.2234+2T>G intronic variant results from a T to G substitution two nucleotides after coding exon 15 in the NBN gene. This alteration occurs at the 3' terminus of the NBN gene, is not expected to trigger nonsense-mediated mRNA decay, and only impacts the last 26 amino acids of the protein. The exact functional effect of this alteration is unknown; however, the impacted region is critical for protein function (Ambry internal data). This nucleotide position is highly conserved in available vertebrate species. In silico splice site analysis predicts that this alteration will weaken the native splice donor site. RNA studies have demonstrated that this alteration results in abnormal splicing in the set of samples tested (Ambry internal data). Alterations that disrupt the canonical splice site are expected to cause aberrant splicing, resulting in an abnormal protein. As such, this alteration is classified as likely pathogenic. -
Aplastic anemia Pathogenic:1
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Microcephaly, normal intelligence and immunodeficiency Pathogenic:1
This sequence change affects a donor splice site in intron 15 of the NBN gene. RNA analysis indicates that disruption of this splice site induces altered splicing and likely disrupts the C-terminus of the protein. This variant is present in population databases (rs142301194, gnomAD 0.0009%). 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: 185026). Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Studies have shown that disruption of this splice site results in skipping of exon 15 and introduces a new termination codon (Invitae). However the mRNA is not expected to undergo nonsense-mediated decay. This variant disrupts the ATM interaction domain of the NBN protein (PMID: 24894818, 21035407), which is important for activating ATM in the double-strand break repair pathway (PMID: 15964794, 15048089). While functional studies have not been performed to directly test the effect of this variant on NBN protein function, this suggests that disruption of this region of the protein is causative of disease. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at