NM_000530.8:c.454A>G

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 3P and 4B. PM1PP2BP4_ModerateBP6BS2_Supporting

The NM_000530.8(MPZ):​c.454A>G​(p.Thr152Ala) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000446 in 1,614,052 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.000039 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000045 ( 0 hom. )

Consequence

MPZ
NM_000530.8 missense

Scores

3
16

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1B:1

Conservation

PhyloP100: 3.05

Publications

1 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: Likely_benign. The variant received -1 ACMG points.

PM1
In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 16 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=0.205737).
BP6
Variant 1-161306459-T-C is Benign according to our data. Variant chr1-161306459-T-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 570626.
BS2
High AC in GnomAd4 at 6 AD gene. Variant has AC lower than other variant known as pathogenic in the gene, so the strength is limited to Supporting.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
MPZNM_000530.8 linkc.454A>G p.Thr152Ala missense_variant Exon 4 of 6 ENST00000533357.5 NP_000521.2 P25189-1
MPZNM_001315491.2 linkc.454A>G p.Thr152Ala missense_variant Exon 4 of 6 NP_001302420.1 P25189A0A5F9ZI26
MPZXM_017001321.3 linkc.484A>G p.Thr162Ala missense_variant Exon 4 of 6 XP_016856810.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
MPZENST00000533357.5 linkc.454A>G p.Thr152Ala missense_variant Exon 4 of 6 1 NM_000530.8 ENSP00000432943.1 P25189-1

Frequencies

GnomAD3 genomes
AF:
0.0000394
AC:
6
AN:
152162
Hom.:
0
Cov.:
32
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:
0.0000735
Gnomad OTH
AF:
0.000479
GnomAD2 exomes
AF:
0.0000680
AC:
17
AN:
249894
AF XY:
0.0000591
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.000145
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.000107
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000451
AC:
66
AN:
1461890
Hom.:
0
Cov.:
33
AF XY:
0.0000440
AC XY:
32
AN XY:
727248
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.0000894
AC:
4
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
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:
0.0000513
AC:
57
AN:
1112012
Other (OTH)
AF:
0.0000828
AC:
5
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.478
Heterozygous variant carriers
0
3
7
10
14
17
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
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:
0.0000394
AC:
6
AN:
152162
Hom.:
0
Cov.:
32
AF XY:
0.0000269
AC XY:
2
AN XY:
74334
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41440
American (AMR)
AF:
0.00
AC:
0
AN:
15280
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5182
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4832
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10622
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000735
AC:
5
AN:
68024
Other (OTH)
AF:
0.000479
AC:
1
AN:
2086
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.433
Heterozygous variant carriers
0
1
1
2
2
3
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:
0.0000900
Hom.:
0
Bravo
AF:
0.0000718
ExAC
AF:
0.0000659
AC:
8
EpiCase
AF:
0.00
EpiControl
AF:
0.000237

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:1Benign:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Charcot-Marie-Tooth disease, type I Uncertain:1
Apr 11, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces threonine, which is neutral and polar, with alanine, which is neutral and non-polar, at codon 152 of the MPZ protein (p.Thr152Ala). This variant is present in population databases (rs764402416, gnomAD 0.01%). This variant has not been reported in the literature in individuals affected with MPZ-related conditions. ClinVar contains an entry for this variant (Variation ID: 570626). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt MPZ protein function with a negative predictive value of 80%. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Inborn genetic diseases Benign:1
Sep 30, 2021
Ambry Genetics
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This alteration is classified as likely 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. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.072
BayesDel_addAF
Benign
-0.032
T
BayesDel_noAF
Uncertain
-0.030
CADD
Benign
22
DANN
Benign
0.91
DEOGEN2
Benign
0.12
T
Eigen
Benign
-0.42
Eigen_PC
Benign
-0.24
FATHMM_MKL
Benign
0.73
D
LIST_S2
Benign
0.73
T
M_CAP
Benign
0.067
D
MetaRNN
Benign
0.21
T
MetaSVM
Benign
-0.36
T
MutationAssessor
Benign
1.0
L
PhyloP100
3.1
PrimateAI
Uncertain
0.56
T
PROVEAN
Benign
-0.45
N
REVEL
Uncertain
0.30
Sift
Benign
0.76
T
Sift4G
Benign
0.49
T
Polyphen
0.057
B
Vest4
0.28
MutPred
0.44
Gain of sheet (P = 0.0049);
MVP
0.94
MPC
0.54
ClinPred
0.056
T
GERP RS
5.4
Varity_R
0.062
gMVP
0.88
Mutation Taster
=79/21
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.14
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: rs764402416; hg19: chr1-161276249; COSMIC: COSV60668320; COSMIC: COSV60668320; API