chr1-161305441-A-C

Variant names:

• chr1-161305441-A-C
• rs868502674
• NM_000530.8:c.*435T>G

Variant summary

Our verdict is Benign. The variant received -8 ACMG points: 0P and 8B. BP4_Strong BS2

The NM_000530.8(MPZ):​c.*435T>G variant causes a 3 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000256 in 191,082 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 (★).

• Frequency:
  • Genomes: 𝑓 0.00025 (0 hom., cov: 30)
  • Exomes 𝑓: 0.00028 (0 hom.)
• Consequence: MPZ NM_000530.8 3_prime_UTR
• Clinical Significance: Uncertain significance criteria provided, single submitter U:4
• Conservation: PhyloP100: 2.09
• 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: Benign. The variant received -8 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.56).
• BS2: High AC in GnomAd4 at 38 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MPZ	NM_000530.8	c.*435T>G		3_prime_UTR_variant	Exon 6 of 6	ENST00000533357.5	NP_000521.2
MPZ	NM_001315491.2	c.*243T>G		3_prime_UTR_variant	Exon 6 of 6		NP_001302420.1
MPZ	XM_017001321.3	c.675+667T>G		intron_variant	Intron 5 of 5		XP_016856810.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MPZ	ENST00000533357.5	c.*435T>G		3_prime_UTR_variant	Exon 6 of 6	1	NM_000530.8	ENSP00000432943.1

Frequencies

GnomAD3 genomes AF: 0.000256 AC: 39 AN: 152106 Hom.: 0 Cov.: 30

Gnomad AFR AF: 0.0000483

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000655

Gnomad ASJ AF: 0.00317

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.000565

Gnomad MID AF: 0.00316

Gnomad NFE AF: 0.000132

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 0.000283 AC: 11 AN: 38858 Hom.: 0 Cov.: 0 AF XY: 0.000240 AC XY: 5 AN XY: 20840

African (AFR) AF: 0.00 AC: 0 AN: 792

American (AMR) AF: 0.000637 AC: 2 AN: 3140

Ashkenazi Jewish (ASJ) AF: 0.00140 AC: 1 AN: 716

East Asian (EAS) AF: 0.00 AC: 0 AN: 1708

South Asian (SAS) AF: 0.00 AC: 0 AN: 6534

European-Finnish (FIN) AF: 0.00108 AC: 2 AN: 1856

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 96

European-Non Finnish (NFE) AF: 0.000181 AC: 4 AN: 22086

Other (OTH) AF: 0.00104 AC: 2 AN: 1930

GnomAD4 genome AF: 0.000250 AC: 38 AN: 152224 Hom.: 0 Cov.: 30 AF XY: 0.000269 AC XY: 20 AN XY: 74416

African (AFR) AF: 0.0000482 AC: 2 AN: 41512

American (AMR) AF: 0.000654 AC: 10 AN: 15298

Ashkenazi Jewish (ASJ) AF: 0.00317 AC: 11 AN: 3470

East Asian (EAS) AF: 0.00 AC: 0 AN: 5174

South Asian (SAS) AF: 0.00 AC: 0 AN: 4830

European-Finnish (FIN) AF: 0.000565 AC: 6 AN: 10614

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

European-Non Finnish (NFE) AF: 0.000132 AC: 9 AN: 68010

Other (OTH) AF: 0.00 AC: 0 AN: 2110

Alfa AF: 0.000214 Hom.: 0

Bravo AF: 0.000230

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:4

Revision: criteria provided, single submitter

Submissions by phenotype

Roussy-Lévy syndrome Uncertain:1

Apr 27, 2017

Illumina Laboratory Services, Illumina

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases did not allow this variant to be ruled in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. -

Charcot-Marie-Tooth disease type 1B Uncertain:1

Apr 27, 2017

Illumina Laboratory Services, Illumina

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases did not allow this variant to be ruled in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. -

Neuropathy, congenital hypomyelinating, 2 Uncertain:1

Apr 27, 2017

Illumina Laboratory Services, Illumina

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases did not allow this variant to be ruled in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. -

Charcot-Marie-Tooth disease dominant intermediate D Uncertain:1

Apr 27, 2017

Illumina Laboratory Services, Illumina

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases did not allow this variant to be ruled in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.56
CADD	Benign	18
DANN	Benign	0.87
PhyloP100		2.1

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

Other links and lift over

dbSNP: rs868502674; hg19: chr1-161275231;