rs1553259703

chr1-161306900-G-A

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_000530.8(MPZ):c.256C>T(p.Gln86Ter) variant causes a stop gained change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 29)
• Consequence: MPZ NM_000530.8 stop_gained
• Clinical Significance: Pathogenic criteria provided, single submitter P:2
• Conservation: PhyloP100: 3.69

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]

ACMG classification

Verdict is Pathogenic. Variant got 12 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 1-161306900-G-A is Pathogenic according to our data. Variant chr1-161306900-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 462792.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MPZ	NM_000530.8	c.256C>T	p.Gln86Ter	stop_gained	3/6	ENST00000533357.5
MPZ	NM_001315491.2	c.256C>T	p.Gln86Ter	stop_gained	3/6
MPZ	XM_017001321.3	c.286C>T	p.Gln96Ter	stop_gained	3/6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MPZ	ENST00000533357.5	c.256C>T	p.Gln86Ter	stop_gained	3/6	1	NM_000530.8	P1

Frequencies

GnomAD3 genomes Cov.: 29

GnomAD4 exome Cov.: 34

GnomAD4 genome Cov.: 29

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, single submitter

Submissions by phenotype

Charcot-Marie-Tooth disease Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

Inherited Neuropathy Consortium

-

- -

Charcot-Marie-Tooth disease, type I Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Invitae

Nov 08, 2017

This sequence change creates a premature translational stop signal (p.Gln86*) in the MPZ gene. It is expected to result in an absent or disrupted protein product. For these reasons, this variant has been classified as Pathogenic. Loss-of-function variants in MPZ are known to be pathogenic (PMID: 14711881). This variant was reported in an individual who was referred for genetic testing for Charcot-Marie-Tooth disease (PMID: 25614874). This variant is not present in population databases (ExAC no frequency). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.58	D
BayesDel_noAF	Pathogenic	0.30
Cadd	Pathogenic	39
Dann	Uncertain	1.0
Eigen	Pathogenic	0.90
Eigen_PC	Pathogenic	0.73
FATHMM_MKL	Benign	0.69	D
MutationTaster	Benign	1.0	A;A;A;D
Vest4		0.77
GERP RS		4.7
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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

Other links and lift over

dbSNP: rs1553259703; hg19: chr1-161276690;