rs997633417

Positions:

chr1-161307419-A-T

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 4P and 6B. PM1PM5BP4_ModerateBS2

The NM_000530.8(MPZ):c.73T>A(p.Ser25Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000682 in 1,614,034 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/21 in silico tools predict 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. S25?) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000068 ( 0 hom. )

Consequence

MPZ
NM_000530.8 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 0.818

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 links:

MPZ (HGNC:):

MPZ links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -2 ACMG points.

PM1

In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 10 uncertain in NM_000530.8

PM5

Other missense variant is known to change same aminoacid residue: Variant chr1-161307418-GA-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 2578457.Status of the report is no_assertion_criteria_provided, 0 stars.

BP4

Computational evidence support a benign effect (MetaRNN=0.088305235).

BS2

High AC in GnomAdExome4 at 10 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MPZ	NM_000530.8 linkuse as main transcript	c.73T>A	p.Ser25Thr	missense_variant	2/6	ENST00000533357.5	NP_000521.2	P25189-1
MPZ	NM_001315491.2 linkuse as main transcript	c.73T>A	p.Ser25Thr	missense_variant	2/6		NP_001302420.1	P25189A0A5F9ZI26
MPZ	XM_017001321.3 linkuse as main transcript	c.103T>A	p.Ser35Thr	missense_variant	2/6		XP_016856810.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MPZ	ENST00000533357.5 linkuse as main transcript	c.73T>A	p.Ser25Thr	missense_variant	2/6	1	NM_000530.8	ENSP00000432943.1		P25189-1

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152266

Hom.:

Cov.:

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

AF:

0.00000684

AC:

AN:

1461768

Hom.:

Cov.:

AF XY:

0.00000825

AC XY:

AN XY:

727182

show subpopulations

Gnomad4 AFR exome

AF:

0.0000896

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000540

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152266

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74392

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: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Athena Diagnostics

Dec 14, 2017

- -

Charcot-Marie-Tooth disease, type I

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Nov 28, 2023

This sequence change replaces serine, which is neutral and polar, with threonine, which is neutral and polar, at codon 25 of the MPZ protein (p.Ser25Thr). This variant is not present in population databases (gnomAD no frequency). 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: 570817). 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. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.078

BayesDel_addAF

Benign

-0.011

BayesDel_noAF

Benign

-0.25

CADD

Benign

DANN

Benign

0.87

DEOGEN2

Benign

0.11

Eigen

Benign

-0.81

Eigen_PC

Benign

-0.78

FATHMM_MKL

Benign

0.26

LIST_S2

Benign

0.49

M_CAP

Benign

0.031

MetaRNN

Benign

0.088

MetaSVM

Benign

-0.62

MutationAssessor

Benign

1.0

PrimateAI

Benign

0.43

PROVEAN

Benign

-0.67

REVEL

Benign

0.20

Sift

Benign

0.12

Sift4G

Benign

0.36

Polyphen

0.0040

Vest4

0.28

MutPred

0.46

Loss of sheet (P = 0.0084);

MVP

0.26

MPC

0.50

ClinPred

0.039

GERP RS

-0.22

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.1

Varity_R

0.056

gMVP

0.53

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.020

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.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over