22-20982397-G-C
Variant summary
Our verdict is Uncertain significance. Variant got -1 ACMG points: 0P and 1B. BP4
This summary comes from the ClinGen Evidence Repository: The NM_006767.4:c.26G>C variant in LZTR1 is a missense variant predicted to cause substitution of glycine by alanine at amino acid 9 (p.Gly9Ala). The highest population minor allele frequency in gnomAD v2.1.1 is 0.0001954 (9/23990 alleles) in the South Asian population (PM2_Supporting, BS1, and BA1 are not met). The computational predictor REVEL gives a score of 0.093, which is below the threshold of 0.3, evidence that does not predict a damaging effect on LZTR1 function (BP4). In summary, this variant meets the criteria to be classified as uncertain significance for RASopathy based on the ACMG/AMP criteria applied, as specified by the ClinGen RASopathy VCEP: BP4. (ClinGen RASopathy VCEP specifications version 1.1; 9/17/2024) LINK:https://erepo.genome.network/evrepo/ui/classification/CA10118269/MONDO:0021060/094
Frequency
Consequence
NM_006767.4 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Uncertain_significance. Variant got -1 ACMG points.
Transcripts
RefSeq
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
---|---|---|---|---|---|---|---|---|
LZTR1 | NM_006767.4 | c.26G>C | p.Gly9Ala | missense_variant | Exon 1 of 21 | ENST00000646124.2 | NP_006758.2 |
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000920 AC: 14AN: 152250Hom.: 0 Cov.: 33
GnomAD3 exomes AF: 0.0000979 AC: 16AN: 163374Hom.: 0 AF XY: 0.000148 AC XY: 13AN XY: 87604
GnomAD4 exome AF: 0.000108 AC: 152AN: 1408454Hom.: 0 Cov.: 32 AF XY: 0.000128 AC XY: 89AN XY: 695686
GnomAD4 genome AF: 0.0000984 AC: 15AN: 152368Hom.: 1 Cov.: 33 AF XY: 0.000107 AC XY: 8AN XY: 74512
ClinVar
Submissions by phenotype
not provided Uncertain:2
This sequence change replaces glycine, which is neutral and non-polar, with alanine, which is neutral and non-polar, at codon 9 of the LZTR1 protein (p.Gly9Ala). This variant is present in population databases (rs756485244, gnomAD 0.04%). This variant has not been reported in the literature in individuals affected with LZTR1-related conditions. ClinVar contains an entry for this variant (Variation ID: 522164). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is not expected to disrupt LZTR1 protein function with a negative predictive value of 95%. 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. -
In silico analysis supports that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -
not specified Benign:2
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Variant summary: LZTR1 c.26G>C (p.Gly9Ala) results in a non-conservative amino acid change in the encoded protein sequence. Four of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 9.8e-05 in 163374 control chromosomes (gnomAD). The observed variant frequency is approximately 20 fold of the estimated maximal expected allele frequency for a pathogenic variant in LZTR1 causing Noonan Syndrome And Related Conditions phenotype (5e-06), strongly suggesting that the variant is benign. To our knowledge, no occurrence of c.26G>C in individuals affected with Noonan Syndrome And Related Conditions and no experimental evidence demonstrating its impact on protein function have been reported. Two ClinVar submitters (evaluation after 2014) cite the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as likely benign. -
Noonan syndrome 10 Uncertain:1
The LZTR1 c.26G>C (p.Gly9Ala) missense change has a maximum subpopulation frequency of 0.038% in gnomAD v2.1.1 (https://gnomad.broadinstitute.org/). The in silico tool REVEL predicts a benign effect on protein function, but to our knowledge this prediction has not been confirmed by functional studies. To our knowledge, this variant has not been reported in individuals with Noonan syndrome or Schwannomatosis. 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. -
LZTR1-related schwannomatosis Uncertain:1
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Hereditary cancer-predisposing syndrome;CN230736:Cardiovascular phenotype Uncertain:1
The p.G9A variant (also known as c.26G>C), located in coding exon 1 of the LZTR1 gene, results from a G to C substitution at nucleotide position 26. The glycine at codon 9 is replaced by alanine, an amino acid with similar properties. This amino acid position is not well conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at