rs876659907
Variant summary
Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM2PP3PP5
The NM_000051.4(ATM):c.2838+4A>G variant causes a splice region, intron change. The variant allele was found at a frequency of 0.00000186 in 1,613,164 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).
Frequency
Consequence
NM_000051.4 splice_region, intron
Scores
Clinical Significance
Conservation
Publications
- hereditary breast carcinomaInheritance: AD Classification: DEFINITIVE Submitted by: Ambry Genetics, ClinGen
- ataxia telangiectasiaInheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Ambry Genetics, Genomics England PanelApp, Labcorp Genetics (formerly Invitae), G2P, ClinGen, Laboratory for Molecular Medicine, Orphanet
- hereditary nonpolyposis colon cancerInheritance: AD Classification: MODERATE, LIMITED Submitted by: ClinGen, Ambry Genetics
- prostate cancerInheritance: AD Classification: MODERATE Submitted by: Ambry Genetics
- sarcomaInheritance: AD Classification: MODERATE Submitted by: Genomics England PanelApp
- familial ovarian cancerInheritance: AD Classification: LIMITED Submitted by: ClinGen
- gastric carcinomaInheritance: AD Classification: LIMITED Submitted by: Ambry Genetics
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ACMG classification
Our verdict: Uncertain_significance. The variant received 4 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| ATM | NM_000051.4 | c.2838+4A>G | splice_region_variant, intron_variant | Intron 18 of 62 | ENST00000675843.1 | NP_000042.3 |
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000131 AC: 2AN: 152198Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.00000398 AC: 1AN: 251224 AF XY: 0.00 show subpopulations
GnomAD4 exome AF: 6.84e-7 AC: 1AN: 1460966Hom.: 0 Cov.: 30 AF XY: 0.00 AC XY: 0AN XY: 726822 show subpopulations ⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.
Age Distribution
GnomAD4 genome AF: 0.0000131 AC: 2AN: 152198Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0AN XY: 74346 show subpopulations
ClinVar
Submissions by phenotype
Ataxia-telangiectasia syndrome Pathogenic:2Uncertain:1
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This sequence change falls in intron 18 of the ATM gene. It does not directly change the encoded amino acid sequence of the ATM protein. RNA analysis indicates that this variant induces altered splicing and may result in an absent or altered protein product. This variant is present in population databases (no rsID available, gnomAD 0.007%). This variant has not been reported in the literature in individuals affected with ATM-related conditions. ClinVar contains an entry for this variant (Variation ID: 232661). Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Studies have shown that this variant results in skipping of exon 18 , and produces a non-functional protein and/or introduces a premature termination codon (Invitae). 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. -
Variant summary: ATM c.2838+4A>G alters a conserved nucleotide located close to a canonical splice site and therefore could affect mRNA splicing, leading to a significantly altered protein sequence. Several computational tools predict a significant impact on normal splicing: Two predict the variant weakens a 5' donor site. Two predict the variant abolishes a 5' splicing donor site. Internal RNA splicing evidence found that this variant affects mRNA splicing in at least 1 individual, resulting in out of frame skipping of exon 18, which is expected to result in nonsense mediated decay (Labcorp, formerly Invitae). The variant allele was found at a frequency of 4e-06 in 251224 control chromosomes. To our knowledge, no occurrence of c.2838+4A>G in individuals affected with Ataxia-Telangiectasia has been reported in the literature. ClinVar contains an entry for this variant (Variation ID: 232661). Based on the evidence outlined above, the variant was classified as likely pathogenic. -
Hereditary cancer-predisposing syndrome Pathogenic:1Uncertain:1
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The c.2838+4A>G intronic variant results from an A to G substitution 4 nucleotides after coding exon 17 in the ATM gene. 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). Based on the majority of available evidence to date, this variant is likely to be pathogenic. -
not provided Pathogenic:1
RNA studies demonstrate a damaging effect: aberrant splicing resulting in exon skipping and a predicted null allele (External communication with Ambry Genetics and Invitae); Observed with a second ATM variant in a patient with ataxia telangiectasia but it is not known whether the variants occurred on the same (in cis) or on different (in trans) chromosomes (Villagaray-Pacheco N. 8-years experience with ataxia telangiectasia: A series of 7 cases. Ro J Neurol., 2021); Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports a deleterious effect on splicing; This variant is associated with the following publications: (PMID: Villagaray-Pacheco2021[article]) -
ATM-related disorder Uncertain:1
The ATM c.2838+4A>G variant is predicted to interfere with splicing. This variant is predicted to disrupt splicing at a consensus splice site based on splicing prediction programs (Alamut Visual Plus v.1.6.1). However, these prediction programs are not equivalent to functional evidence. To our knowledge, this variant has not been reported in the literature. This variant is reported in 0.0062% of alleles in individuals of African descent in gnomAD (http://gnomad.broadinstitute.org/variant/11-108139340-A-G) and has been interpreted as uncertain in ClinVar (https://preview.ncbi.nlm.nih.gov/clinvar/variation/232661). Of note, other variants impacting the c.2838 consensus splice site (c.2838G>T, c.2838+1G>A, and c.2838+6T>C) have been documented in patients with breast cancer (Patient MK1C in Table S1, Hamameh et al. 2017. PubMed ID: 28486781), ataxia telangiectasia (referred to as IVS18+1G>A in Buzin et al. 2003. PubMed ID: 12552559), and dystonia (Patient IS-DYS-094 in Suppl. Table 2, Zech et al. 2020. PubMed ID: 33098801), respectively. At this time, the clinical significance of the c.2838+4A>G variant is uncertain due to the absence of conclusive functional and genetic evidence. -
Familial cancer of breast Uncertain:1
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Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at