1-155910695-T-G
Variant summary
Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PM1PM2PM5PP3_ModeratePP5_Very_Strong
The NM_006912.6(RIT1):c.67A>C(p.Lys23Gln) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. K23N) has been classified as Pathogenic.
Frequency
Consequence
NM_006912.6 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Pathogenic. Variant got 16 ACMG points.
Transcripts
RefSeq
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
---|---|---|---|---|---|---|---|---|
RIT1 | NM_006912.6 | c.67A>C | p.Lys23Gln | missense_variant | Exon 2 of 6 | ENST00000368323.8 | NP_008843.1 | |
RIT1 | NM_001256821.2 | c.118A>C | p.Lys40Gln | missense_variant | Exon 2 of 6 | NP_001243750.1 | ||
RIT1 | NM_001256820.2 | c.-2-189A>C | intron_variant | Intron 1 of 4 | NP_001243749.1 |
Ensembl
Frequencies
GnomAD3 genomes Cov.: 33
GnomAD4 exome Cov.: 32
GnomAD4 genome Cov.: 33
ClinVar
Submissions by phenotype
Noonan syndrome 8 Pathogenic:2
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This sequence change replaces lysine, which is basic and polar, with glutamine, which is neutral and polar, at codon 23 of the RIT1 protein (p.Lys23Gln). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individuals with clinical features of Noonan syndrome (PMID: 28554332; internal data). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 224122). 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 expected to disrupt RIT1 protein function with a positive predictive value of 95%. This variant disrupts the p.Lys23 amino acid residue in RIT1. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 26518681, 27101134, 29734338; internal data). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -
Hypertelorism;C0239340:Pedal edema;C0349588:Short stature;C0423110:Downslanted palpebral fissures Pathogenic:1
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not provided Pathogenic:1
Not observed in large population cohorts (Lek et al., 2016); In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect; This variant is associated with the following publications: (PMID: 26518681, 28554332) -
Cardiovascular phenotype Pathogenic:1
The p.K23Q variant (also known as c.67A>C), located in coding exon 1 of the RIT1 gene, results from an A to C substitution at nucleotide position 67. The lysine at codon 23 is replaced by glutamine, an amino acid with similar properties. This variant has been detected in individuals with features consistent with Noonan syndrome, including a de novo occurrence (Bowling KM et al. Genome Med, 2017 May;9:43; external communication). This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). This amino acid position is highly conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Based on the majority of available evidence to date, this variant is likely to be pathogenic. -
not specified Uncertain:1
Variant classified as Uncertain Significance - Favor Pathogenic. The p.Lys40Gln variant in RIT1 has not been previously reported in individuals with clinical fe atures of a RASopathy and is absent from large population studies. However, anot her variant at the same position (p.Lys40Asn; reported as p.Lys23Asn on NM_00691 2.5) was identified as a de novo variant in 1 individual with Noonan syndrome (N emcikova 2015), suggesting changes at this position are not tolerated. Computati onal prediction tools and conservation analysis suggest that the p.Lys40Gln vari ant may impact the protein, though this information is not predictive enough to determine pathogenicity. In summary, while there is some suspicion for a pathoge nic role, the clinical significance of the p.Lys40Gln variant is uncertain. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at