rs200151353

Variant summary

Our verdict is Benign. The variant received -10 ACMG points: 3P and 13B. PM1PP2BP4_StrongBP6BS1BS2

The NM_000530.8(MPZ):​c.133C>T​(p.Arg45Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000102 in 1,614,236 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. 14/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R45Q) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.00045 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000065 ( 1 hom. )

Consequence

MPZ
NM_000530.8 missense

Scores

1
5
13

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2B:3

Conservation

PhyloP100: 1.09

Publications

2 publications found
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]
MPZ Gene-Disease associations (from GenCC):
  • Charcot-Marie-Tooth disease
    Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
  • Charcot-Marie-Tooth disease type 1B
    Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Laboratory for Molecular Medicine, Orphanet
  • neuropathy, congenital hypomyelinating, 2
    Inheritance: AD Classification: DEFINITIVE Submitted by: G2P
  • autosomal dominant intermediate Charcot-Marie-Tooth disease with neuropathic pain
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • Charcot-Marie-Tooth disease dominant intermediate D
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • Charcot-Marie-Tooth disease type 2I
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • Charcot-Marie-Tooth disease type 2J
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • Charcot-Marie-Tooth disease type 3
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Benign. The variant received -10 ACMG points.

PM1
In a hotspot region, there are 12 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 21 uncertain in NM_000530.8
PP2
Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 84 curated pathogenic missense variants (we use a threshold of 10). The gene has 1 curated benign missense variants. Gene score misZ: 0.98749 (below the threshold of 3.09). Trascript score misZ: 1.4782 (below the threshold of 3.09). GenCC associations: The gene is linked to Charcot-Marie-Tooth disease dominant intermediate D, Charcot-Marie-Tooth disease type 1B, autosomal dominant intermediate Charcot-Marie-Tooth disease with neuropathic pain, Charcot-Marie-Tooth disease type 2J, neuropathy, congenital hypomyelinating, 2, Charcot-Marie-Tooth disease type 2I, Charcot-Marie-Tooth disease type 3, Charcot-Marie-Tooth disease.
BP4
Computational evidence support a benign effect (MetaRNN=0.04703018).
BP6
Variant 1-161307359-G-A is Benign according to our data. Variant chr1-161307359-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 246524.
BS1
Variant frequency is greater than expected in population afr. GnomAd4 allele frequency = 0.000453 (69/152366) while in subpopulation AFR AF = 0.00156 (65/41588). AF 95% confidence interval is 0.00126. There are 0 homozygotes in GnomAd4. There are 29 alleles in the male GnomAd4 subpopulation. Median coverage is 33. This position passed quality control check.
BS2
High AC in GnomAd4 at 69 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
MPZNM_000530.8 linkc.133C>T p.Arg45Trp missense_variant Exon 2 of 6 ENST00000533357.5 NP_000521.2 P25189-1
MPZNM_001315491.2 linkc.133C>T p.Arg45Trp missense_variant Exon 2 of 6 NP_001302420.1 P25189A0A5F9ZI26
MPZXM_017001321.3 linkc.163C>T p.Arg55Trp missense_variant Exon 2 of 6 XP_016856810.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
MPZENST00000533357.5 linkc.133C>T p.Arg45Trp missense_variant Exon 2 of 6 1 NM_000530.8 ENSP00000432943.1 P25189-1

Frequencies

GnomAD3 genomes
AF:
0.000453
AC:
69
AN:
152248
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.00157
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000131
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.000207
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.000179
AC:
45
AN:
251256
AF XY:
0.000140
show subpopulations
Gnomad AFR exome
AF:
0.00160
Gnomad AMR exome
AF:
0.000318
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000880
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000650
AC:
95
AN:
1461870
Hom.:
1
Cov.:
32
AF XY:
0.0000605
AC XY:
44
AN XY:
727236
show subpopulations
African (AFR)
AF:
0.00146
AC:
49
AN:
33480
American (AMR)
AF:
0.000313
AC:
14
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.0000383
AC:
1
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.000232
AC:
20
AN:
86256
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53418
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00000450
AC:
5
AN:
1111992
Other (OTH)
AF:
0.0000993
AC:
6
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.489
Heterozygous variant carriers
0
6
12
17
23
29
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Exome Hom
Variant carriers
0
4
8
12
16
20
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.000453
AC:
69
AN:
152366
Hom.:
0
Cov.:
33
AF XY:
0.000389
AC XY:
29
AN XY:
74508
show subpopulations
African (AFR)
AF:
0.00156
AC:
65
AN:
41588
American (AMR)
AF:
0.000131
AC:
2
AN:
15298
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5194
South Asian (SAS)
AF:
0.000207
AC:
1
AN:
4832
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10622
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68040
Other (OTH)
AF:
0.00
AC:
0
AN:
2114
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.496
Heterozygous variant carriers
0
5
10
15
20
25
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.000150
Hom.:
0
Bravo
AF:
0.000544
ESP6500AA
AF:
0.000681
AC:
3
ESP6500EA
AF:
0.00
AC:
0
ExAC
AF:
0.000157
AC:
19

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:2Benign:3
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Dejerine-Sottas disease;C0205713:Roussy-Lévy syndrome;C0270912:Charcot-Marie-Tooth disease type 1B;C1843075:Charcot-Marie-Tooth disease dominant intermediate D;C1843153:Charcot-Marie-Tooth disease type 2J;C3888087:Charcot-Marie-Tooth disease type 2I;C4721436:Charcot-Marie-Tooth disease type 4E Uncertain:1
Oct 31, 2018
Fulgent Genetics, Fulgent Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not provided Uncertain:1
Nov 10, 2016
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The A638T variant has not been published as a pathogenic variant, nor has it been reported as a benign variant to our knowledge. It was not observed in approximately 6,500 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, indicating it is not a common benign variant in these populations. The A638T variant is a non-conservative amino acid substitution, which is likely to impact secondary protein structure as these residues differ in polarity, charge, size and/or other properties. However, this substitution occurs at a position that is not conserved, and in silico analysis predicts this variant likely does not alter the protein structure/function. Therefore, based on the currently available information, it is unclear whether this variant is a pathogenic variant or a rare benign variant -

Inborn genetic diseases Benign:1
Jan 05, 2022
Ambry Genetics
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This alteration is classified as benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

MPZ-related disorder Benign:1
May 17, 2022
PreventionGenetics, part of Exact Sciences
Significance:Likely benign
Review Status:no assertion criteria provided
Collection Method:clinical testing

This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -

Charcot-Marie-Tooth disease, type I Benign:1
Jan 20, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.22
BayesDel_addAF
Benign
-0.32
T
BayesDel_noAF
Benign
-0.24
CADD
Uncertain
25
DANN
Pathogenic
1.0
DEOGEN2
Uncertain
0.56
D
Eigen
Benign
0.15
Eigen_PC
Benign
0.077
FATHMM_MKL
Benign
0.23
N
LIST_S2
Uncertain
0.94
D
M_CAP
Benign
0.075
D
MetaRNN
Benign
0.047
T
MetaSVM
Benign
-0.77
T
MutationAssessor
Benign
1.7
L
PhyloP100
1.1
PrimateAI
Benign
0.30
T
PROVEAN
Uncertain
-3.2
D
REVEL
Benign
0.28
Sift
Uncertain
0.0050
D
Sift4G
Uncertain
0.021
D
Polyphen
1.0
D
Vest4
0.39
MVP
0.43
MPC
1.2
ClinPred
0.079
T
GERP RS
3.1
PromoterAI
0.0052
Neutral
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.0
Varity_R
0.29
gMVP
0.78
Mutation Taster
=290/10
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.030
Details are displayed if max score is > 0.2

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

Publications

Other links and lift over

dbSNP: rs200151353; hg19: chr1-161277149; API