17-15239482-T-C

Position:

• chr17-15239482-T-C

Variant summary

Our verdict is Likely pathogenic. Variant got 9 ACMG points: 9P and 0B. PM1 PM2 PP3_Strong PP5

The NM_000304.4(PMP22):​c.308A>G​(p.Gln103Arg) 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 Conflicting classifications of pathogenicity (no stars).

• Frequency: Genomes: not found (cov: 33)
• Consequence: PMP22 NM_000304.4 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 7.85

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 Likely_pathogenic. Variant got 9 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
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.944
• PP5: Variant 17-15239482-T-C is Pathogenic according to our data. Variant chr17-15239482-T-C is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 188095.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=1, Uncertain_significance=1, Pathogenic=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
PMP22	NM_000304.4	c.308A>G	p.Gln103Arg	missense_variant	4/5	ENST00000312280.9	NP_000295.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
PMP22	ENST00000312280.9	c.308A>G	p.Gln103Arg	missense_variant	4/5	1	NM_000304.4	ENSP00000308937	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

GeneDx

Jan 06, 2023

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -

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

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Sep 15, 2022

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. For these reasons, this variant has been classified as Pathogenic. ClinVar contains an entry for this variant (Variation ID: 188095). This missense change has been observed in individual(s) with clinical features of PMP22-related conditions (Invitae). In at least one individual the variant was observed to be de novo. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces glutamine, which is neutral and polar, with arginine, which is basic and polar, at codon 103 of the PMP22 protein (p.Gln103Arg). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.95
BayesDel_addAF	Pathogenic	0.47	D
BayesDel_noAF	Pathogenic	0.43
CADD	Pathogenic	27
DANN	Benign	0.96
DEOGEN2	Pathogenic	0.97	D;D;D;D;D;.;.;D;.
Eigen	Pathogenic	0.81
Eigen_PC	Pathogenic	0.78
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.90	D;.;.;.;.;D;D;D;D
M_CAP	Pathogenic	0.32	D
MetaRNN	Pathogenic	0.94	D;D;D;D;D;D;D;D;D
MetaSVM	Uncertain	0.70	D
MutationAssessor	Pathogenic	3.2	M;M;M;.;.;.;.;.;.
MutationTaster	Benign	1.0	D;D;D;D;D
PrimateAI	Uncertain	0.64	T
PROVEAN	Uncertain	-3.4	.;D;D;.;D;.;.;.;D
REVEL	Pathogenic	0.90
Sift	Uncertain	0.0010	.;D;D;.;D;.;.;.;D
Sift4G	Benign	0.067	T;T;T;.;D;.;.;.;T
Polyphen		1.0	D;D;D;.;.;.;.;.;.
Vest4		0.93
MutPred		0.83		Gain of MoRF binding (P = 0.0371);Gain of MoRF binding (P = 0.0371);Gain of MoRF binding (P = 0.0371);Gain of MoRF binding (P = 0.0371);Gain of MoRF binding (P = 0.0371);.;.;Gain of MoRF binding (P = 0.0371);Gain of MoRF binding (P = 0.0371);
MVP		0.97
MPC		1.3
ClinPred		0.97	D
GERP RS		5.8
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.76
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: rs786204064; hg19: chr17-15142799;