rs200151353

Variant names:

• chr1-161307359-G-A
• rs200151353
• NM_000530.8:c.133C>T

Variant summary

Our verdict is Benign. The variant received -10 ACMG points: 3P and 13B. PM1 PP2 BP4_Strong BP6 BS1 BS2

The NM_000530.8(MPZ):​c.133C>T​(p.Arg45Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000102 in 1,614,236 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. 14/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R45Q) has been classified as Likely benign.

• Frequency:
  • Genomes: 𝑓 0.00045 (0 hom., cov: 33)
  • Exomes 𝑓: 0.000065 (1 hom.)
• Consequence: MPZ NM_000530.8 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2 B:3
• Conservation: PhyloP100: 1.09
• Publications: 2 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: Laboratory for Molecular Medicine, Labcorp Genetics (formerly Invitae), 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: Benign. The variant received -10 ACMG points.

• PM1: In a hotspot region, there are 12 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 21 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 neuropathy, congenital hypomyelinating, 2, Charcot-Marie-Tooth disease, Charcot-Marie-Tooth disease type 1B, Charcot-Marie-Tooth disease dominant intermediate D, Charcot-Marie-Tooth disease type 2J, Charcot-Marie-Tooth disease type 3, Charcot-Marie-Tooth disease type 2I, autosomal dominant intermediate Charcot-Marie-Tooth disease with neuropathic pain.
• BP4: Computational evidence support a benign effect (MetaRNN=0.04703018).
• BP6: Variant 1-161307359-G-A is Benign according to our data. Variant chr1-161307359-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 246524.
• BS1: Variant frequency is greater than expected in population afr. GnomAd4 allele frequency = 0.000453 (69/152366) while in subpopulation AFR AF = 0.00156 (65/41588). AF 95% confidence interval is 0.00126. There are 0 homozygotes in GnomAd4. There are 29 alleles in the male GnomAd4 subpopulation. Median coverage is 33. This position passed quality control check.
• BS2: High AC in GnomAd4 at 69 AD gene.

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

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MPZ	NM_000530.8	MANE Select	c.133C>T	p.Arg45Trp	missense	Exon 2 of 6	NP_000521.2	P25189-1
	MPZ	NM_001315491.2		c.133C>T	p.Arg45Trp	missense	Exon 2 of 6	NP_001302420.1	A0A5F9ZI26

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MPZ	ENST00000533357.5	TSL:1 MANE Select	c.133C>T	p.Arg45Trp	missense	Exon 2 of 6	ENSP00000432943.1	P25189-1
	MPZ	ENST00000463290.5	TSL:1	n.133C>T		non_coding_transcript_exon	Exon 2 of 7	ENSP00000431538.1	P25189-1
	MPZ	ENST00000672287.2		c.-456C>T		5_prime_UTR_premature_start_codon_gain	Exon 1 of 5	ENSP00000499818.2	E9PL80

Frequencies

GnomAD3 genomes AF: 0.000453 AC: 69 AN: 152248 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.00157

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000131

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.000207

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.000179 AC: 45 AN: 251256 AF XY: 0.000140

Gnomad AFR exome AF: 0.00160

Gnomad AMR exome AF: 0.000318

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000880

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000650 AC: 95 AN: 1461870 Hom.: 1 Cov.: 32 AF XY: 0.0000605 AC XY: 44 AN XY: 727236

African (AFR) AF: 0.00146 AC: 49 AN: 33480

American (AMR) AF: 0.000313 AC: 14 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.0000383 AC: 1 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.000232 AC: 20 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: 0.00000450 AC: 5 AN: 1111992

Other (OTH) AF: 0.0000993 AC: 6 AN: 60396

GnomAD4 genome AF: 0.000453 AC: 69 AN: 152366 Hom.: 0 Cov.: 33 AF XY: 0.000389 AC XY: 29 AN XY: 74508

African (AFR) AF: 0.00156 AC: 65 AN: 41588

American (AMR) AF: 0.000131 AC: 2 AN: 15298

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5194

South Asian (SAS) AF: 0.000207 AC: 1 AN: 4832

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10622

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 294

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 68040

Other (OTH) AF: 0.00 AC: 0 AN: 2114

Alfa AF: 0.000150 Hom.: 0

Bravo AF: 0.000544

ESP6500AA AF: 0.000681 AC: 3

ESP6500EA AF: 0.00 AC: 0

ExAC AF: 0.000157 AC: 19

ClinVar

ClinVar submissions

Significance: Conflicting classifications of pathogenicity

Revision: criteria provided, conflicting classifications

Pathogenic	VUS	Benign	Condition
-	-	1	Charcot-Marie-Tooth disease, type I (1)
-	1	-	Dejerine-Sottas disease;C0205713:Roussy-Lévy syndrome;C0270912:Charcot-Marie-Tooth disease type 1B;C1843075:Charcot-Marie-Tooth disease dominant intermediate D;C1843153:Charcot-Marie-Tooth disease type 2J;C3888087:Charcot-Marie-Tooth disease type 2I;C4721436:Charcot-Marie-Tooth disease type 4E (1)
-	-	1	Inborn genetic diseases (1)
-	-	1	MPZ-related disorder (1)
-	1	-	not provided (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.22
BayesDel_addAF	Benign	-0.32	T
BayesDel_noAF	Benign	-0.24
CADD	Uncertain	25
DANN	Pathogenic	1.0
DEOGEN2	Uncertain	0.56	D
Eigen	Benign	0.15
Eigen_PC	Benign	0.077
FATHMM_MKL	Benign	0.23	N
LIST_S2	Uncertain	0.94	D
M_CAP	Benign	0.075	D
MetaRNN	Benign	0.047	T
MetaSVM	Benign	-0.77	T
MutationAssessor	Benign	1.7	L
PhyloP100		1.1
PrimateAI	Benign	0.30	T
PROVEAN	Uncertain	-3.2	D
REVEL	Benign	0.28
Sift	Uncertain	0.0050	D
Sift4G	Uncertain	0.021	D
Polyphen		1.0	D
Vest4		0.39
MVP		0.43
MPC		1.2
ClinPred		0.079	T
GERP RS		3.1
PromoterAI		0.0052	Neutral
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.0
Varity_R		0.29
gMVP		0.78
Mutation Taster		=290/10	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.030		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: rs200151353; hg19: chr1-161277149;