MPZ

Chr 1ADAR

myelin protein zero

Also known as: CMT1, CMT1B, CMT2I, CMT2J, CMT4E, CMTDI3, CMTDID, DSS

The encoded protein is a major structural glycoprotein of peripheral myelin that forms and stabilizes the compact myelin sheath in Schwann cells. Mutations cause a spectrum of autosomal dominant and recessive peripheral neuropathies including Charcot-Marie-Tooth disease types 1B and 2I/2J, Dejerine-Sottas disease, congenital hypomyelinating neuropathy, and Roussy-Levy syndrome. The pathogenic mechanism involves dominant-negative effects that disrupt normal myelin formation and maintenance.

OMIMResearchSummary from RefSeq, OMIM, UniProt, Mechanism
MultiplemechanismAD/ARLOEUF 0.647 OMIM phenotypes
Clinical SummaryMPZ
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Gene-Disease Validity (ClinGen)
Charcot-Marie-Tooth disease · ADDefinitive

Definitive — sufficient evidence for diagnostic panels

Population Constraint (gnomAD)
Constrained for loss-of-function variants (OE-LoF 0.25) despite low pLI — interpret in context.

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

Tolerant — LoF & missense variants common in population
LoF Constraint
0.64LOEUF
pLI 0.272
Z-score 2.43
OE 0.25 (0.110.64)
Tolerant

Typical tolerance to LoF variation

Missense Constraint
0.99Z-score
OE missense 0.77 (0.660.90)
109 obs / 142.1 exp
Tolerant

Mild missense constraint

Observed / Expected Ratios
LoF OE0.25 (0.110.64)
00.351.4
Missense OE0.77 (0.660.90)
00.61.4
Synonymous OE0.82
01.21.6
LoF obs/exp: 3 / 12.2Missense obs/exp: 109 / 142.1Syn Z: 1.08
Curated Mechanism (G2P)Gene2Phenotype (DDG2P) ↗
definitiveMPZ-related neuropathy, congenital hypomyelinatingOTHERAD
DN
0.7230th %ile
GOF
0.6833th %ile
LOF
0.3941th %ile

This gene has evidence for multiple mechanisms of pathogenicity (dominant-negative, gain-of-function and loss-of-function). Both the Badonyi & Marsh prediction and the broader genomic evidence point to dominant-negative as the predominant mechanism. Different variants in this gene may act through different mechanisms — interpret in context of the specific variant.

DNprediction above median · 1 literature citation
GOFprediction above median · 1 literature citation
LOF1 literature citation

Note: In-silico variant effect predictors (SIFT, PolyPhen, REVEL, CADD) may underestimate pathogenicity of missense variants in genes with GOF or DN mechanisms. Consider functional evidence and clinical context.

Literature Evidence

DNThe two early-onset mutations caused two distinct abnormalities. H52R was correctly glycosylated and trafficked to the plasma membrane, but strongly affected intercellular adhesion. When co-expressed with wild-type MPZ (wtMPZ), a functional dominant negative effect was observed.PMID:18337304
GOFMPZ mutations cause neuropathy gain of function mechanisms that are largely independent MPZs normal role of mediating myelin compaction.PMID:25002989
LOFLoss of function MPZ mutation causes milder CMT1B neuropathy.PMID:33960567

Predictions from Badonyi M, Marsh JA. PLoS ONE. 2024;19(8):e0307312.

ClinVar Variant Classifications

0 submitted variants in ClinVar

Protein Context — Lollipop Plot

MPZ · protein map & ClinVar variants

Showing all ClinVar variants across the protein. Search a specific variant to highlight its position.

3D Protein StructureAlphaFold

Clinical Trials

Active and recruiting trials from ClinicalTrials.gov

No active trials found for this gene.

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Clinical Literature
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