17-15230952-C-G

Position:

• chr17-15230952-C-G

Variant summary

Our verdict is Pathogenic. Variant got 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 Pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G150C) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 33)
• Consequence: PMP22 NM_000304.4 missense
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 7.76

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]

ACMG classification

Verdict is Pathogenic. Variant got 18 ACMG points.

• PM1: In a chain Peripheral myelin protein 22 (size 159) in uniprot entity PMP22_HUMAN there are 53 pathogenic changes around while only 3 benign (95%) 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 Lovd as [Pathogenic].
• 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]. Clinvar id is 384327.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr17-15230952-C-G is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
PMP22	NM_000304.4	c.448G>C	p.Gly150Arg	missense_variant	5/5	ENST00000312280.9	NP_000295.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
PMP22	ENST00000312280.9	c.448G>C	p.Gly150Arg	missense_variant	5/5	1	NM_000304.4	ENSP00000308937	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

GeneDx

May 20, 2020

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) -

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

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Apr 24, 2023

This variant is not present in population databases (gnomAD no frequency). For these reasons, this variant has been classified as Pathogenic. 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. 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. ClinVar contains an entry for this variant (Variation ID: 384327). This missense change has been observed in individuals with Charcot-Marie-Tooth disease (PMID: 26392352; Invitae). 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;.
MutationTaster	Benign	1.0	D;D;D;D
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

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

Publications

LitVar

Other links and lift over

dbSNP: rs104894624; hg19: chr17-15134269;