17-15230952-C-G

Variant names:

• chr17-15230952-C-G
• rs104894624
• NM_000304.4:c.448G>C

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PM1 PM2 PM5 PP3_Strong PP5_Very_Strong

The NM_000304.4(PMP22):​c.448G>C​(p.Gly150Arg) variant causes a missense change involving the alteration of a conserved nucleotide. 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 Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G150C) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 33)
• Consequence: PMP22 NM_000304.4 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 7.76
• Publications: 9 publications found

Genes affected

PMP22 (HGNC:9118): (peripheral myelin protein 22) This gene encodes an integral membrane protein that is a major component of myelin in the peripheral nervous system. Studies suggest two alternately used promoters drive tissue-specific expression. Various mutations of this gene are causes of Charcot-Marie-Tooth disease Type IA, Dejerine-Sottas syndrome, and hereditary neuropathy with liability to pressure palsies. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jul 2013]

PMP22 Gene-Disease associations (from GenCC):

• Charcot-Marie-Tooth disease type 1A

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae), ClinGen, Laboratory for Molecular Medicine, Ambry Genetics
• hereditary neuropathy with liability to pressure palsies

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, Orphanet
• Charcot-Marie-Tooth disease type 1E

  Inheritance: AD Classification: STRONG, MODERATE, SUPPORTIVE Submitted by: Ambry Genetics, PanelApp Australia, Orphanet, Labcorp Genetics (formerly Invitae)
• Charcot-Marie-Tooth disease type 3

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Pathogenic. The variant received 18 ACMG points.

• PM1: In a hotspot region, there are 5 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 6 uncertain in NM_000304.4
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr17-15230952-C-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 8439.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.981
• PP5: Variant 17-15230952-C-G is Pathogenic according to our data. Variant chr17-15230952-C-G is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 384327.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
PMP22	NM_000304.4	c.448G>C	p.Gly150Arg	missense_variant	Exon 5 of 5	ENST00000312280.9	NP_000295.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
PMP22	ENST00000312280.9	c.448G>C	p.Gly150Arg	missense_variant	Exon 5 of 5	1	NM_000304.4	ENSP00000308937.3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:1

May 20, 2020

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Not observed in large population cohorts (Lek et al., 2016); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 26392352) -

Dejerine-Sottas disease Pathogenic:1

Dec 19, 2023

3billion

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The variant is not observed in the gnomAD v2.1.1 dataset. Predicted Consequence/Location: Missense variant In silico tool predictions suggest damaging effect of the variant on gene or gene product [REVEL: 0.96 (>=0.6, sensitivity 0.68 and specificity 0.92); 3Cnet: 0.98 (>=0.6, sensitivity 0.72 and precision 0.9)]. Same nucleotide change resulting in same amino acid change has been previously reported as pathogenic/likely pathogenic with strong evidence (ClinVar ID: VCV000384327 /PMID: 26392352). Different missense changes at the same codon (p.Gly150Asp, p.Gly150Cys, p.Gly150Val) have been reported as pathogenic/likely pathogenic with strong evidence (ClinVar ID: VCV000008439, VCV000245805, VCV000433198 /PMID: 28600779, 8995589, 9544841). Therefore, this variant is classified as Likely pathogenic according to the recommendation of ACMG/AMP guideline. -

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

Apr 24, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This missense change has been observed in individuals with Charcot-Marie-Tooth disease (PMID: 26392352; Invitae). ClinVar contains an entry for this variant (Variation ID: 384327). 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 expected to disrupt PMP22 protein function. This variant disrupts the p.Gly150 amino acid residue in PMP22. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 8995589, 9425015, 10078969, 10982389, 15474367, 15537650, 18795802, 25385046, 26102530). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces glycine, which is neutral and non-polar, with arginine, which is basic and polar, at codon 150 of the PMP22 protein (p.Gly150Arg). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.57	D
BayesDel_noAF	Pathogenic	0.58
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.98	D;D;D;.
Eigen	Pathogenic	0.75
Eigen_PC	Uncertain	0.65
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.92	D;.;.;D
M_CAP	Pathogenic	0.55	D
MetaRNN	Pathogenic	0.98	D;D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	3.3	M;M;M;.
PhyloP100		7.8
PrimateAI	Uncertain	0.73	T
PROVEAN	Pathogenic	-6.4	.;D;D;.
REVEL	Pathogenic	0.96
Sift	Uncertain	0.0010	.;D;D;.
Sift4G	Uncertain	0.0020	D;D;D;.
Polyphen		1.0	D;D;D;.
Vest4		0.91
MutPred		0.88		Gain of MoRF binding (P = 0.0028);Gain of MoRF binding (P = 0.0028);Gain of MoRF binding (P = 0.0028);.;
MVP		0.98
MPC		1.4
ClinPred		1.0	D
GERP RS		5.0
Varity_R		0.77
gMVP		0.96
Mutation Taster		=0/100	disease causing (ClinVar)

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: rs104894624; hg19: chr17-15134269;