11-108244868-G-T
Variant summary
Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PP3_ModeratePP5
The NM_000051.4(ATM):c.743G>T(p.Arg248Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000479 in 1,461,616 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 Conflicting classifications of pathogenicity (no stars).
Frequency
Consequence
NM_000051.4 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Uncertain_significance. Variant got 3 ACMG points.
Transcripts
RefSeq
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
---|---|---|---|---|---|---|---|---|
ATM | NM_000051.4 | c.743G>T | p.Arg248Leu | missense_variant | Exon 7 of 63 | ENST00000675843.1 | NP_000042.3 |
Ensembl
Frequencies
GnomAD3 genomes Cov.: 31
GnomAD3 exomes AF: 0.00000398 AC: 1AN: 251016Hom.: 0 AF XY: 0.00 AC XY: 0AN XY: 135660
GnomAD4 exome AF: 0.00000479 AC: 7AN: 1461616Hom.: 0 Cov.: 32 AF XY: 0.00000688 AC XY: 5AN XY: 727106
GnomAD4 genome Cov.: 31
ClinVar
Submissions by phenotype
Hereditary cancer-predisposing syndrome Pathogenic:2
This missense variant replaces arginine with leucine at codon 248 of the ATM protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function. To our knowledge, functional studies have not been reported for this variant. This variant has been reported in the compound heterozygous state with another pathogenic ATM variant in individuals affected with atypical form of ataxia-telangiectasia (PMID: 24120321, 30713931). Cells derived from these individuals have shown residual ATM kinase activity (PMID: 24120321, 30549301). This variant has been identified in 1/251016 chromosomes in the general population by the Genome Aggregation Database (gnomAD). Based on the available evidence, this variant is classified as Likely Pathogenic. Since this variant has been associated with a mild form of an autosomal-recessive disease, it appears to be hypomorphic and may display reduced cancer penetrance relative to typical pathogenic ATM variants. Medical management of heterozygous individuals should be considered based on the individual's personal and family history. -
The p.R248L variant (also known as c.743G>T), located in coding exon 6 of the ATM gene, results from a G to T substitution at nucleotide position 743. The arginine at codon 248 is replaced by leucine, an amino acid with dissimilar properties. This variant has been identified in conjunction with other pathogenic ATM variant(s) in individual(s) with features consistent with ataxia telangiectasia (Cummins G et al. Parkinsonism Relat. Disord., 2013 Dec;19:1173-4; Georgiev D et al. Mov Disord Clin Pract Jan;3:405-408). Lymphoblastoid cell from these patients showed reduced levels of ATM protein but retained kinase activity. This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the majority of available evidence to date, this variant is likely to be pathogenic. -
Ataxia-telangiectasia syndrome Pathogenic:1Uncertain:1
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This sequence change replaces arginine, which is basic and polar, with leucine, which is neutral and non-polar, at codon 248 of the ATM protein (p.Arg248Leu). This variant is present in population databases (no rsID available, gnomAD 0.006%). This missense change has been observed in individuals with clinical features of ataxia-telangiectasia (PMID: 24120321, 26896183, 30713931). ClinVar contains an entry for this variant (Variation ID: 453684). 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 Pathogenic:1Uncertain:1
Observed multiple times in the compound heterozygous state with a truncating ATM variant (phase unknown) in patients with atypical ataxia telangiectasia (Cummins 2013, Georgiev 2016); Published functional studies are conflicting: ATM protein expression is reduced and ATM kinase activity is retained (Cummins 2013); Not observed at significant frequency in large population cohorts (gnomAD); 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: 25040471, 27226433, 24120321, 26896183, 30549301, 30713931) -
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Familial cancer of breast Pathogenic:1
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not specified Uncertain:1
DNA sequence analysis of the ATM gene demonstrated a sequence change, c.743G>T, in exon 7 that results in an amino acid change, p.Arg248Leu. This sequence change has been previously described in individuals with ataxia telangiectasia with myoclonus-dystonia who also had a truncating nonsense variant in the same gene (PMID: 24120321, 30713931, 30549301). Functional studies in the Lymphoblastoid cell from these patients showed reduced expression of mutant ATM protein with some retained ATM kinase activity. This sequence change has been described in the gnomAD database in one individual which corresponds to a population frequency of 0.0004% (dbSNP rs769166447). The p.Arg248Leu change affects a highly conserved amino acid residue located in a domain of the ATM protein that is not known to be functional. The p.Arg248Leu substitution appears to be deleterious using several in-silico pathogenicity prediction tools (SIFT, PolyPhen2, Align GVGD, REVEL). Due to insufficient evidences, the clinical significance of the p.Arg248Leu change remains unknown at this time. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at