chr17-15239535-G-C

Variant names:

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 3P and 5B. PM1PP3BS1_SupportingBS2

The NM_000304.4(PMP22):c.255C>G(p.Cys85Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000582 in 1,613,930 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000062 ( 0 hom. )

Consequence

PMP22
NM_000304.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:6

Conservation

PhyloP100: 3.33

Publications

0 publications found

Variant links:

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

PMP22 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -2 ACMG points.

PM1

In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 6 uncertain in NM_000304.4

PP3

MetaRNN computational evidence supports a deleterious effect, 0.799

BS1

Variant frequency is greater than expected in population afr. GnomAdExome4 allele frequency = 0.0000623 (91/1461682) while in subpopulation AFR AF = 0.000179 (6/33470). AF 95% confidence interval is 0.0000771. There are 0 homozygotes in GnomAdExome4. There are 42 alleles in the male GnomAdExome4 subpopulation. Median coverage is 33. This position passed quality control check. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

BS2

High AC in GnomAdExome4 at 91 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
PMP22	NM_000304.4 link	c.255C>G	p.Cys85Trp	missense_variant	Exon 4 of 5	ENST00000312280.9	NP_000295.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
PMP22	ENST00000312280.9 link	c.255C>G	p.Cys85Trp	missense_variant	Exon 4 of 5	1	NM_000304.4	ENSP00000308937.3		Q01453

Frequencies

GnomAD3 genomes

AF:

0.0000197

AC:

AN:

152248

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000441

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000159

AC:

AN:

251460

AF XY:

0.0000294

show subpopulations

Gnomad AFR exome

AF:

0.0000615

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000264

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000623

AC:

AN:

1461682

Hom.:

Cov.:

AF XY:

0.0000578

AC XY:

AN XY:

727168

show subpopulations

African (AFR)

AF:

0.000179

AC:

AN:

33470

American (AMR)

AF:

0.00

AC:

AN:

44718

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26132

East Asian (EAS)

AF:

0.00

AC:

AN:

39700

South Asian (SAS)

AF:

0.00

AC:

AN:

86248

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53420

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.0000747

AC:

AN:

1111846

Other (OTH)

AF:

0.0000331

AC:

AN:

60380

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.491

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

GnomAD4 genome

AF:

0.0000197

AC:

AN:

152248

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74382

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41466

American (AMR)

AF:

0.00

AC:

AN:

15288

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5194

South Asian (SAS)

AF:

0.00

AC:

AN:

4834

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10626

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000441

AC:

AN:

68046

Other (OTH)

AF:

0.00

AC:

AN:

2094

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.475

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Alfa

AF:

0.0000282

Hom.:

Bravo

AF:

0.0000302

TwinsUK

AF:

0.00

AC:

ALSPAC

AF:

0.000259

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:6

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Uncertain:2

Jun 28, 2021

Athena Diagnostics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Jun 03, 2019

Mayo Clinic Laboratories, Mayo Clinic

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Distal spinal muscular atrophy

Uncertain:1

Aug 14, 2019

Genesis Genome Database

Significance:Uncertain significance

Review Status:no assertion criteria provided

Collection Method:research

- -

Inborn genetic diseases

Uncertain:1

Nov 09, 2021

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The p.C85W variant (also known as c.255C>G), located in coding exon 3 of the PMP22 gene, results from a C to G substitution at nucleotide position 255. The cysteine at codon 85 is replaced by tryptophan, an amino acid with highly dissimilar properties. This amino acid position is conserved. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Dejerine-Sottas disease;C0205713:Roussy-Lévy syndrome;C0270911:Charcot-Marie-Tooth disease, type IA;C0393814:Hereditary liability to pressure palsies;C3495591:Charcot-Marie-Tooth disease type 1E;C4083008:Guillain-Barre syndrome, familial

Uncertain:1

Mar 16, 2022

Fulgent Genetics, Fulgent Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Charcot-Marie-Tooth disease, type I

Uncertain:1

Dec 15, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces cysteine, which is neutral and slightly polar, with tryptophan, which is neutral and slightly polar, at codon 85 of the PMP22 protein (p.Cys85Trp). This variant is present in population databases (rs755701957, gnomAD 0.004%). This variant has not been reported in the literature in individuals affected with PMP22-related conditions. ClinVar contains an entry for this variant (Variation ID: 531692). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.68

BayesDel_addAF

Uncertain

0.072

BayesDel_noAF

Uncertain

0.050

CADD

Uncertain

(source)

DANN

Uncertain

0.98

DEOGEN2

Pathogenic

0.81

D;D;D;D;D;.;.;D;.

Eigen

Uncertain

0.63

Eigen_PC

Uncertain

0.64

FATHMM_MKL

Uncertain

0.96

LIST_S2

Benign

0.82

T;.;.;.;.;T;T;D;D

M_CAP

Uncertain

0.20

MetaRNN

Pathogenic

0.80

D;D;D;D;D;D;D;D;D

MetaSVM

Uncertain

0.53

MutationAssessor

Uncertain

2.4

M;M;M;.;.;.;.;.;.

PhyloP100

3.3

PrimateAI

Pathogenic

0.82

PROVEAN

Uncertain

-2.8

.;D;D;.;D;.;.;.;D

REVEL

Uncertain

0.59

Sift

Benign

0.18

.;T;T;.;T;.;.;.;T

Sift4G

Benign

0.18

T;T;T;.;D;.;.;.;D

Polyphen

0.94

P;P;P;.;.;.;.;.;.

Vest4

0.70

MutPred

0.63

Gain of MoRF binding (P = 0.0688);Gain of MoRF binding (P = 0.0688);Gain of MoRF binding (P = 0.0688);Gain of MoRF binding (P = 0.0688);Gain of MoRF binding (P = 0.0688);.;.;Gain of MoRF binding (P = 0.0688);Gain of MoRF binding (P = 0.0688);

MVP

0.32

MPC

1.5

ClinPred

0.85

GERP RS

5.6

Varity_R

0.36

gMVP

0.84

Mutation Taster

=31/69

disease causing

(source)

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

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chr17-15239535-G-C

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over