rs145039212

Variant names:

• chr1-161306839-C-G
• rs145039212
• NM_000530.8:c.317G>C

Your query was ambiguous. Multiple possible variants found:

• chr1-161306839-C-G
• chr1-161306839-C-T

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 7P and 1B. PM1 PM2 PM5 PP2 BP4

The NM_000530.8(MPZ):​c.317G>C​(p.Arg106Pro) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,842 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/22 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. R106C) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 29)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: MPZ NM_000530.8 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -2.01
• Publications: 0 publications found

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

ACMG classification

Our verdict: Likely_pathogenic. The variant received 6 ACMG points.

• PM1: In a hotspot region, there are 19 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 21 uncertain in NM_000530.8
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr1-161306840-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 637797.
• 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=0.33018422).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000530.8. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MPZ	NM_000530.8	MANE Select	c.317G>C	p.Arg106Pro	missense	Exon 3 of 6	NP_000521.2
	MPZ	NM_001315491.2		c.317G>C	p.Arg106Pro	missense	Exon 3 of 6	NP_001302420.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MPZ	ENST00000533357.5	TSL:1 MANE Select	c.317G>C	p.Arg106Pro	missense	Exon 3 of 6	ENSP00000432943.1
	MPZ	ENST00000463290.5	TSL:1	n.317G>C		non_coding_transcript_exon	Exon 3 of 7	ENSP00000431538.1
	MPZ	ENST00000672602.2		c.317G>C	p.Arg106Pro	missense	Exon 3 of 6	ENSP00000500814.2

Frequencies

GnomAD3 genomes Cov.: 29

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461842 Hom.: 0 Cov.: 34 AF XY: 0.00000138 AC XY: 1 AN XY: 727218

African (AFR) AF: 0.00 AC: 0 AN: 33478

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: 86256

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53418

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5754

European-Non Finnish (NFE) AF: 0.00000180 AC: 2 AN: 1111982

Other (OTH) AF: 0.00 AC: 0 AN: 60394

GnomAD4 genome Cov.: 29

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Oct 01, 2018

Athena Diagnostics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.57
BayesDel_addAF	Benign	-0.082	T
BayesDel_noAF	Benign	-0.36
CADD	Benign	16
DANN	Uncertain	0.99
DEOGEN2	Benign	0.22	T
Eigen	Benign	-0.36
Eigen_PC	Benign	-0.48
FATHMM_MKL	Benign	0.18	N
LIST_S2	Benign	0.71	T
M_CAP	Benign	0.027	D
MetaRNN	Benign	0.33	T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	1.8	L
PhyloP100		-2.0
PrimateAI	Benign	0.23	T
PROVEAN	Benign	-1.3	N
REVEL	Benign	0.20
Sift	Benign	0.27	T
Sift4G	Benign	0.14	T
Polyphen		0.93	P
Vest4		0.50
MutPred		0.44		Gain of catalytic residue at W107 (P = 0.0101)
MVP		0.78
MPC		1.2
ClinPred		0.38	T
GERP RS		-1.5
Varity_R		0.77
gMVP		0.98
Mutation Taster		=37/63	disease causing

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

Other links and lift over

dbSNP: rs145039212; hg19: chr1-161276629;