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

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 29)

Consequence

MPZ
NM_000530.8 missense

Scores

10
8
1

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:13

Conservation

PhyloP100: 7.17
Variant links:
Genes affected
MPZ (HGNC:7225): (myelin protein zero) This gene is specifically expressed in Schwann cells of the peripheral nervous system and encodes a type I transmembrane glycoprotein that is a major structural protein of the peripheral myelin sheath. The encoded protein contains a large hydrophobic extracellular domain and a smaller basic intracellular domain, which are essential for the formation and stabilization of the multilamellar structure of the compact myelin. Mutations in this gene are associated with autosomal dominant form of Charcot-Marie-Tooth disease type 1 (CMT1B) and other polyneuropathies, such as Dejerine-Sottas syndrome (DSS) and congenital hypomyelinating neuropathy (CHN). A recent study showed that two isoforms are produced from the same mRNA by use of alternative in-frame translation termination codons via a stop codon readthrough mechanism. [provided by RefSeq, Oct 2015]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 18 ACMG points.

PM1
In a hotspot region, there are 8 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 13 uncertain in NM_000530.8
PM2
Very rare variant in population databases, with high coverage;
PM5
Other missense variant is known to change same aminoacid residue: Variant chr1-161306864-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 14175.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.989
PP5
Variant 1-161306863-C-T is Pathogenic according to our data. Variant chr1-161306863-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 14176.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr1-161306863-C-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
MPZNM_000530.8 linkc.293G>A p.Arg98His missense_variant Exon 3 of 6 ENST00000533357.5 NP_000521.2 P25189-1
MPZNM_001315491.2 linkc.293G>A p.Arg98His missense_variant Exon 3 of 6 NP_001302420.1 P25189A0A5F9ZI26
MPZXM_017001321.3 linkc.323G>A p.Arg108His missense_variant Exon 3 of 6 XP_016856810.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
MPZENST00000533357.5 linkc.293G>A p.Arg98His missense_variant Exon 3 of 6 1 NM_000530.8 ENSP00000432943.1 P25189-1

Frequencies

GnomAD3 genomes
AF:
0.00000658
AC:
1
AN:
151962
Hom.:
0
Cov.:
29
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD4 exome
Cov.:
34
GnomAD4 genome
AF:
0.00000658
AC:
1
AN:
151962
Hom.:
0
Cov.:
29
AF XY:
0.00
AC XY:
0
AN XY:
74222
show subpopulations
Gnomad4 AFR
AF:
0.00
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.0000147
Gnomad4 OTH
AF:
0.00
Bravo
AF:
0.00000378

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:13
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Pathogenic:6
Aug 08, 2024
Athena Diagnostics
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

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. -

May 29, 2024
GeneDx
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

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) -

Jan 20, 2022
Mayo Clinic Laboratories, Mayo Clinic
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

PM1, PM2, PS3, PS4 -

-
Joint Genome Diagnostic Labs from Nijmegen and Maastricht, Radboudumc and MUMC+
Significance: Pathogenic
Review Status: no assertion criteria provided
Collection Method: clinical testing

- -

Oct 01, 2021
CeGaT Center for Human Genetics Tuebingen
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

-
Clinical Genetics, Academic Medical Center
Significance: Pathogenic
Review Status: no assertion criteria provided
Collection Method: clinical testing

- -

Charcot-Marie-Tooth disease type 1B Pathogenic:2
Feb 23, 2023
3billion
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

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. -

Sep 10, 2002
OMIM
Significance: Pathogenic
Review Status: no assertion criteria provided
Collection Method: literature only

- -

Charcot-Marie-Tooth disease Pathogenic:1
-
Molecular Genetics Laboratory, London Health Sciences Centre
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Inborn genetic diseases Pathogenic:1
Mar 25, 2020
Ambry Genetics
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

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
Oct 21, 2022
PreventionGenetics, part of Exact Sciences
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

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
Dec 11, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

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
Sep 19, 2014
Centre for Mendelian Genomics, University Medical Centre Ljubljana
Significance: Likely pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

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Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.87
BayesDel_addAF
Pathogenic
0.37
D
BayesDel_noAF
Pathogenic
0.29
CADD
Pathogenic
33
DANN
Pathogenic
1.0
DEOGEN2
Uncertain
0.74
D
Eigen
Pathogenic
0.78
Eigen_PC
Pathogenic
0.73
FATHMM_MKL
Uncertain
0.94
D
LIST_S2
Uncertain
0.89
D
M_CAP
Uncertain
0.12
D
MetaRNN
Pathogenic
0.99
D
MetaSVM
Uncertain
0.0018
D
MutationAssessor
Uncertain
2.7
M
PrimateAI
Uncertain
0.70
T
PROVEAN
Uncertain
-4.3
D
REVEL
Pathogenic
0.68
Sift
Pathogenic
0.0
D
Sift4G
Pathogenic
0.0
D
Polyphen
1.0
D
Vest4
0.95
MutPred
0.95
Loss of ubiquitination at K96 (P = 0.0506);
MVP
0.98
MPC
1.7
ClinPred
1.0
D
GERP RS
4.7
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.92
gMVP
1.0

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.0
Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs121913589; hg19: chr1-161276653; COSMIC: COSV100337829; COSMIC: COSV100337829; API