rs573456055

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 3P and 2B. PM1PP2BP4BS2_Supporting

The NM_000530.8(MPZ):​c.530A>G​(p.Tyr177Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000434 in 1,613,942 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. Y177N) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000039 ( 0 hom., cov: 32)
Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

MPZ
NM_000530.8 missense

Scores

6
13

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 2.15

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: Uncertain_significance. The variant received 1 ACMG points.

PM1
In a transmembrane_region Helical (size 25) in uniprot entity MYP0_HUMAN there are 4 pathogenic changes around while only 0 benign (100%) 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=0.4229379).
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.530A>G p.Tyr177Cys missense_variant Exon 4 of 6 ENST00000533357.5 NP_000521.2 P25189-1
MPZNM_001315491.2 linkc.530A>G p.Tyr177Cys missense_variant Exon 4 of 6 NP_001302420.1 P25189A0A5F9ZI26
MPZXM_017001321.3 linkc.560A>G p.Tyr187Cys 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.530A>G p.Tyr177Cys missense_variant Exon 4 of 6 1 NM_000530.8 ENSP00000432943.1 P25189-1

Frequencies

GnomAD3 genomes
AF:
0.0000395
AC:
6
AN:
151932
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.000121
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
GnomAD2 exomes
AF:
0.0000120
AC:
3
AN:
250866
AF XY:
0.00000737
show subpopulations
Gnomad AFR exome
AF:
0.000123
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000883
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
6.84e-7
AC:
1
AN:
1461894
Hom.:
0
Cov.:
33
AF XY:
0.00
AC XY:
0
AN XY:
727248
show subpopulations
African (AFR)
AF:
0.0000299
AC:
1
AN:
33480
American (AMR)
AF:
0.00
AC:
0
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:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53420
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1112012
Other (OTH)
AF:
0.00
AC:
0
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.575
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
GnomAD4 genome
AF:
0.0000395
AC:
6
AN:
152048
Hom.:
0
Cov.:
32
AF XY:
0.0000269
AC XY:
2
AN XY:
74338
show subpopulations
African (AFR)
AF:
0.000121
AC:
5
AN:
41464
American (AMR)
AF:
0.00
AC:
0
AN:
15280
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5136
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4824
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10580
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
67980
Other (OTH)
AF:
0.00
AC:
0
AN:
2110
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.433
Heterozygous variant carriers
0
1
2
2
3
4
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:
0.00
Hom.:
0
Bravo
AF:
0.0000264
ExAC
AF:
0.0000247
AC:
3

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Charcot-Marie-Tooth disease, type I Uncertain:1
Feb 10, 2020
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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. This sequence change replaces tyrosine with cysteine at codon 177 of the MPZ protein (p.Tyr177Cys). The tyrosine residue is highly conserved and there is a large physicochemical difference between tyrosine and cysteine. This variant is present in population databases (rs573456055, ExAC 0.02%). This variant has not been reported in the literature in individuals with MPZ-related disease. Algorithms developed to predict the effect of missense changes on protein structure and function do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.10
BayesDel_addAF
Benign
-0.036
T
BayesDel_noAF
Uncertain
-0.050
CADD
Pathogenic
27
DANN
Uncertain
0.99
DEOGEN2
Benign
0.14
T
Eigen
Benign
-0.51
Eigen_PC
Benign
-0.43
FATHMM_MKL
Uncertain
0.85
D
LIST_S2
Benign
0.82
T
M_CAP
Uncertain
0.092
D
MetaRNN
Benign
0.42
T
MetaSVM
Benign
-0.60
T
MutationAssessor
Benign
1.8
L
PhyloP100
2.1
PrimateAI
Uncertain
0.66
T
PROVEAN
Benign
-0.38
N
REVEL
Uncertain
0.38
Sift
Benign
0.041
D
Sift4G
Benign
0.16
T
Polyphen
0.0030
B
Vest4
0.70
MutPred
0.58
Loss of catalytic residue at L172 (P = 0.0669);
MVP
0.82
MPC
1.6
ClinPred
0.16
T
GERP RS
1.6
Varity_R
0.11
gMVP
0.98
Mutation Taster
=75/25
polymorphism

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

Other links and lift over

dbSNP: rs573456055; hg19: chr1-161276173; COSMIC: COSV60667609; API