rs121913591
Variant summary
Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PM1PM2PM5PP3_StrongPP5_Very_Strong
The NM_000530.8(MPZ):c.293G>A(p.Arg98His) variant causes a missense change. The variant allele was found at a frequency of 0.00000658 in 151,962 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 Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R98L) has been classified as Likely pathogenic.
Frequency
Consequence
NM_000530.8 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Pathogenic. Variant got 18 ACMG points.
Transcripts
RefSeq
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
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MPZ | NM_000530.8 | c.293G>A | p.Arg98His | missense_variant | Exon 3 of 6 | ENST00000533357.5 | NP_000521.2 | |
MPZ | NM_001315491.2 | c.293G>A | p.Arg98His | missense_variant | Exon 3 of 6 | NP_001302420.1 | ||
MPZ | XM_017001321.3 | c.323G>A | p.Arg108His | missense_variant | Exon 3 of 6 | XP_016856810.1 |
Ensembl
Frequencies
GnomAD3 genomes AF: 0.00000658 AC: 1AN: 151962Hom.: 0 Cov.: 29
GnomAD4 exome Cov.: 34
GnomAD4 genome AF: 0.00000658 AC: 1AN: 151962Hom.: 0 Cov.: 29 AF XY: 0.00 AC XY: 0AN XY: 74222
ClinVar
Submissions by phenotype
not provided Pathogenic:6
The frequency of this variant in the general population is consistent with pathogenicity. (http://gnomad.broadinstitute.org) This variant has been identified in multiple unrelated individuals with autosomal dominant Charcot-Marie-Tooth disease. This variant segregates with disease in multiple families. Assessment of experimental evidence suggests this variant results in abnormal protein function. (PMID: 20461396, 29687021) The variant is located in a region that is considered important for protein function and/or structure. At least one other missense variant at this codon is considered to be pathogenic or likely pathogenic, suggesting this variant may also cause disease. -
Published functional studies demonstrate a damaging effect on cell adhesiveness (PMID: 20461396); Not observed at significant frequency in large population cohorts (gnomAD); Missense variants in this gene are a common cause of disease and they are underrepresented in the general population; 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: 31211173, 33179255, 31372974, 12221176, 8797476, 7688964, 10737979, 20215982, 10581375, 11437164, 29687021, 32376792, 33726816, 36203352, 37273706, 29136549, 10545037, 37581289, 15729519, 34925207, 12477701, 26310628, 20461396, 8644725, 21840889, 22689911) -
PM1, PM2, PS3, PS4 -
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Charcot-Marie-Tooth disease type 1B Pathogenic:2
The variant is not observed in the gnomAD v2.1.1 dataset. In silico tool predictions suggest damaging effect of the variant on gene or gene product (REVEL: 0.68; 3Cnet: 1.00). Same nucleotide change resulting in same amino acid change (ClinVar ID: VCV000014176) and different missense changes at the same codon (p.Arg98Cys, p.Arg98Leu, p.Arg98Pro / ClinVar ID: VCV000014174, VCV000014175, VCV000586152) Therefore, this variant is classified as Pathogenic according to the recommendation of ACMG/AMP guideline. -
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Charcot-Marie-Tooth disease Pathogenic:1
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Inborn genetic diseases Pathogenic:1
The p.R98H pathogenic mutation (also known as c.293G>A), located in coding exon 3 of the MPZ gene, results from a G to A substitution at nucleotide position 293. The arginine at codon 98 is replaced by histidine, an amino acid with highly similar properties. This alteration has been reported in multiple individuals with demyelinating Charcot-Marie Tooth disease and to co-segregate with disease in multiple families (Lagueny A et al. Neuromuscul. Disord., 1999 Oct;9:361-7; Ohnishi A et al. J. Neurol. Sci., 1999 Dec;171:97-109; Rouger H et al. Am. J. Hum. Genet., 1996 Mar;58:638-41). Additionally, in vitro functional studies have shown that protein with this alteration fails to localize to the cell membrane and increases the unfolded protein response in the cell (Bai Y et al. Ann Clin Transl Neurol, 2018 Apr;5:445-455; Lee YC et al. J. Neurol., 2010 Oct;257:1661-8). This variant was not reported in population-based cohorts in the Genome Aggregation Database (gnomAD). Based on the supporting evidence, this alteration is interpreted as a disease-causing mutation. -
MPZ-related disorder Pathogenic:1
The MPZ c.293G>A variant is predicted to result in the amino acid substitution p.Arg98His. This variant has been reported in many individuals and families with Charcot-Marie-Tooth disease, type 1B (Ohnishi et al. 1999. PubMed ID: 10581375; Lee et al. 2010. PubMed ID: 20461396; Hsu et al. 2019. PubMed ID: 31211173; Volodarsky et al. 2020. PubMed ID: 32376792; Hayasaka et al. 1993. PubMed ID: 7688964; Gabreëls-Festen et al. 1996. PubMed ID: 8797476). This variant has not been reported in a large population database (http://gnomad.broadinstitute.org), indicating this variant is rare. This variant is interpreted as pathogenic. -
Charcot-Marie-Tooth disease, type I Pathogenic:1
This sequence change replaces arginine, which is basic and polar, with histidine, which is basic and polar, at codon 98 of the MPZ protein (p.Arg98His). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individuals with Charcot-Marie-Tooth disease type 1 (PMID: 7688964, 8644725, 10581375, 12477701, 20215982). It has also been observed to segregate with disease in related individuals. Invitae Evidence Modeling of clinical and family history, age, sex, and reported ancestry of multiple individuals with this MPZ variant has been performed. This variant is expected to be pathogenic with a positive predictive value of at least 99%. This is a validated machine learning model that incorporates the clinical features of 11,906 individuals referred to our laboratory for MPZ testing. ClinVar contains an entry for this variant (Variation ID: 14176). 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 MPZ protein function with a positive predictive value of 80%. Experimental studies have shown that this missense change affects MPZ function (PMID: 20461396). For these reasons, this variant has been classified as Pathogenic. -
Sensory neuropathy;C0427065:Distal muscle weakness;C0728829:Pes cavus;C1836451:Distal lower limb amyotrophy;C1857640:Decreased nerve conduction velocity Pathogenic:1
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Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at