chr19-40395144-G-A

Position:

• chr19-40395144-G-A

Variant summary

Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PVS1_Strong PM2 PP5_Very_Strong

The NM_181882.3(PRX):​c.3208C>T​(p.Arg1070Ter) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000684 in 1,461,848 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 Likely pathogenic (★★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000068 (0 hom.)
• Consequence: PRX NM_181882.3 stop_gained
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:5 U:1 O:1
• Conservation: PhyloP100: -0.454

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]

ACMG classification

Verdict is Pathogenic. Variant got 14 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. There are 11 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 19-40395144-G-A is Pathogenic according to our data. Variant chr19-40395144-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 4794.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr19-40395144-G-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
PRX	NM_181882.3	c.3208C>T	p.Arg1070Ter	stop_gained	7/7	ENST00000324001.8
PRX	NM_001411127.1	c.3493C>T	p.Arg1165Ter	stop_gained	7/7
PRX	XM_017027047.2	c.3106C>T	p.Arg1036Ter	stop_gained	4/4
PRX	NM_020956.2	c.*3413C>T		3_prime_UTR_variant	6/6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
PRX	ENST00000324001.8	c.3208C>T	p.Arg1070Ter	stop_gained	7/7	1	NM_181882.3	A2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000796 AC: 2 AN: 251332 Hom.: 0 AF XY: 0.0000147 AC XY: 2 AN XY: 135846

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.0000653

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000684 AC: 10 AN: 1461848 Hom.: 0 Cov.: 99 AF XY: 0.00000688 AC XY: 5 AN XY: 727220

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.000176

Gnomad4 SAS exome AF: 0.0000232

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Alfa AF: 0.0000279 Hom.: 0

Bravo AF: 0.0000113

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:5 Uncertain:1 Other:1

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Charcot-Marie-Tooth disease type 4F Pathogenic:2 Other:1

not provided, no classification provided	literature only	GeneReviews	-	- -
Pathogenic, criteria provided, single submitter	clinical testing	CMT Laboratory, Bogazici University	Dec 01, 2020	- -
Pathogenic, no assertion criteria provided	literature only	OMIM	Nov 01, 2012	- -

Dejerine-Sottas disease Pathogenic:2

Likely pathogenic, criteria provided, single submitter	clinical testing	3billion	Jan 03, 2022	Stop-gained (nonsense): predicted to result in a loss or disruption of normal protein function through protein truncation. The predicted truncated protein may be shortened by more than 10% (PVS1_S). The variant has been reported at least twice as pathogenic/likely pathogenic with clinical assertions and evidence for the classification (ClinVar ID: VCV000004794, PMID:15197604). It is observed at an extremely low frequency in the gnomAD v2.1.1 dataset (total allele frequency: 0.000008, PM2_M). Therefore, this variant is classified as pathogenic according to the recommendation of ACMG/AMP guideline. -
Pathogenic, criteria provided, single submitter	research	Centre for Translational Omics - GOSgene, University College London	Oct 22, 2012	- -

Charcot-Marie-Tooth disease type 4 Pathogenic:1 Uncertain:1

Uncertain significance, no assertion criteria provided	research	Genesis Genome Database	Aug 14, 2019	- -
Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	May 25, 2023	For these reasons, this variant has been classified as Pathogenic. ClinVar contains an entry for this variant (Variation ID: 4794). This premature translational stop signal has been observed in individual(s) with Charcot-Marie-Tooth disease (PMID: 15197604, 15469949, 16770524, 22847150, 26059842). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. It has also been observed to segregate with disease in related individuals. This variant is present in population databases (rs104894708, gnomAD 0.006%). This sequence change creates a premature translational stop signal (p.Arg1070*) in the PRX gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 392 amino acid(s) of the PRX protein. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.29	D
BayesDel_noAF	Pathogenic	0.36
CADD	Pathogenic	38
DANN	Uncertain	1.0
Eigen	Uncertain	0.44
Eigen_PC	Uncertain	0.25
FATHMM_MKL	Benign	0.39	N
MutationTaster	Benign	1.0	A;A
Vest4		0.79
GERP RS		2.4

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: rs104894708; hg19: chr19-40901051;