19-40395662-C-T

Variant summary

Our verdict is Likely benign. The variant received -4 ACMG points: 0P and 4B. BP4_Strong

The NM_181882.3(PRX):​c.2690G>A​(p.Arg897Gln) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000304 in 1,614,048 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R897P) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000039 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000029 ( 0 hom. )

Consequence

PRX
NM_181882.3 missense

Scores

3
16

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:5

Conservation

PhyloP100: 1.25

Publications

2 publications found
Variant links:
Genes affected
PRX (HGNC:13797): (periaxin) This gene encodes a protein involved in peripheral nerve myelin upkeep. The encoded protein contains 2 PDZ domains which were named after PSD95 (post synaptic density protein), DlgA (Drosophila disc large tumor suppressor), and ZO1 (a mammalian tight junction protein). Two alternatively spliced transcript variants have been described for this gene which encode different protein isoforms and which are targeted differently in the Schwann cell. Mutations in this gene cause Charcot-Marie-Tooth neuoropathy, type 4F and Dejerine-Sottas neuropathy. [provided by RefSeq, Jul 2008]
PRX Gene-Disease associations (from GenCC):
  • Charcot-Marie-Tooth disease type 4
    Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
  • Charcot-Marie-Tooth disease type 4F
    Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet, Ambry Genetics
  • Charcot-Marie-Tooth disease type 3
    Inheritance: AD, AR Classification: MODERATE, SUPPORTIVE Submitted by: Orphanet, Ambry Genetics

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -4 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.051315874).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
PRXNM_181882.3 linkc.2690G>A p.Arg897Gln missense_variant Exon 7 of 7 ENST00000324001.8 NP_870998.2 Q9BXM0-1
PRXNM_001411127.1 linkc.2975G>A p.Arg992Gln missense_variant Exon 7 of 7 NP_001398056.1
PRXXM_017027047.2 linkc.2588G>A p.Arg863Gln missense_variant Exon 4 of 4 XP_016882536.1
PRXNM_020956.2 linkc.*2895G>A 3_prime_UTR_variant Exon 6 of 6 NP_066007.1 Q9BXM0-2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
PRXENST00000324001.8 linkc.2690G>A p.Arg897Gln missense_variant Exon 7 of 7 1 NM_181882.3 ENSP00000326018.6 Q9BXM0-1

Frequencies

GnomAD3 genomes
AF:
0.0000394
AC:
6
AN:
152178
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000483
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000654
Gnomad ASJ
AF:
0.000576
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000558
AC:
14
AN:
250984
AF XY:
0.0000442
show subpopulations
Gnomad AFR exome
AF:
0.000250
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.000298
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000528
Gnomad OTH exome
AF:
0.000164
GnomAD4 exome
AF:
0.0000294
AC:
43
AN:
1461870
Hom.:
0
Cov.:
100
AF XY:
0.0000289
AC XY:
21
AN XY:
727240
show subpopulations
African (AFR)
AF:
0.000149
AC:
5
AN:
33478
American (AMR)
AF:
0.00
AC:
0
AN:
44722
Ashkenazi Jewish (ASJ)
AF:
0.000459
AC:
12
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86258
European-Finnish (FIN)
AF:
0.0000187
AC:
1
AN:
53414
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5764
European-Non Finnish (NFE)
AF:
0.0000189
AC:
21
AN:
1112002
Other (OTH)
AF:
0.0000662
AC:
4
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.487
Heterozygous variant carriers
0
4
8
11
15
19
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.0000394
AC:
6
AN:
152178
Hom.:
0
Cov.:
33
AF XY:
0.0000269
AC XY:
2
AN XY:
74346
show subpopulations
African (AFR)
AF:
0.0000483
AC:
2
AN:
41442
American (AMR)
AF:
0.0000654
AC:
1
AN:
15284
Ashkenazi Jewish (ASJ)
AF:
0.000576
AC:
2
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5182
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4828
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10618
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68032
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.467
Heterozygous variant carriers
0
1
2
3
4
5
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.0000937
Hom.:
0
Bravo
AF:
0.0000453
TwinsUK
AF:
0.00
AC:
0
ALSPAC
AF:
0.000259
AC:
1
ExAC
AF:
0.0000494
AC:
6
EpiCase
AF:
0.00
EpiControl
AF:
0.000178

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:5
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Charcot-Marie-Tooth disease Uncertain:1
-
Molecular Genetics Laboratory, London Health Sciences Centre
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Inborn genetic diseases Uncertain:1
Jun 18, 2021
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.R897Q variant (also known as c.2690G>A), located in coding exon 4 of the PRX gene, results from a G to A substitution at nucleotide position 2690. The arginine at codon 897 is replaced by glutamine, an amino acid with highly similar properties. This amino acid position is not well conserved in available vertebrate species, and glutamine is the reference amino acid in other vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

not provided Uncertain:1
Jul 26, 2023
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

In silico analysis supports that this missense variant does not alter protein structure/function; Reported previously as a variant of uncertain significance in a patient with a suspected diagnosis of Charcot-Marie-Tooth disease; however, clinical and segregation information was not provided (Volodarsky et al., 2021); This variant is associated with the following publications: (PMID: 32376792) -

Charcot-Marie-Tooth disease type 4F Uncertain:1
Jan 13, 2018
Illumina Laboratory Services, Illumina
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Charcot-Marie-Tooth disease type 4 Uncertain:1
Aug 31, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces arginine, which is basic and polar, with glutamine, which is neutral and polar, at codon 897 of the PRX protein (p.Arg897Gln). This variant is present in population databases (rs752531623, gnomAD 0.04%). This missense change has been observed in individual(s) with clinical suspicion of Charcot-Marie-Tooth disease (PMID: 32376792). ClinVar contains an entry for this variant (Variation ID: 242181). Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated. 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
Benign
0.085
BayesDel_addAF
Benign
-0.36
T
BayesDel_noAF
Benign
-0.47
CADD
Benign
17
DANN
Uncertain
1.0
DEOGEN2
Benign
0.12
T
Eigen
Benign
-0.28
Eigen_PC
Benign
-0.17
FATHMM_MKL
Benign
0.024
N
LIST_S2
Benign
0.82
T
M_CAP
Benign
0.016
T
MetaRNN
Benign
0.051
T
MetaSVM
Benign
-0.64
T
MutationAssessor
Uncertain
2.3
M
PhyloP100
1.3
PrimateAI
Benign
0.24
T
PROVEAN
Benign
-0.31
N
REVEL
Benign
0.074
Sift
Benign
0.052
T
Sift4G
Uncertain
0.023
D
Polyphen
0.41
B
Vest4
0.25
MVP
0.38
MPC
0.48
ClinPred
0.048
T
GERP RS
4.2
Varity_R
0.049
gMVP
0.19
Mutation Taster
=77/23
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.010
Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

Other links and lift over

dbSNP: rs752531623; hg19: chr19-40901569; COSMIC: COSV99397522; API