rs878855285

Variant names:

• chr19-40394048-A-G
• rs878855285
• NM_181882.3:c.4304T>C

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_181882.3(PRX):​c.4304T>C​(p.Val1435Ala) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 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. V1435M) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: PRX NM_181882.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.87
• Publications: 0 publications found

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

ACMG classification

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
PRX	NM_181882.3	c.4304T>C	p.Val1435Ala	missense_variant	Exon 7 of 7	ENST00000324001.8	NP_870998.2
PRX	NM_001411127.1	c.4589T>C	p.Val1530Ala	missense_variant	Exon 7 of 7		NP_001398056.1
PRX	XM_017027047.2	c.4202T>C	p.Val1401Ala	missense_variant	Exon 4 of 4		XP_016882536.1
PRX	NM_020956.2	c.*4509T>C		3_prime_UTR_variant	Exon 6 of 6		NP_066007.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
PRX	ENST00000324001.8	c.4304T>C	p.Val1435Ala	missense_variant	Exon 7 of 7	1	NM_181882.3	ENSP00000326018.6

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Charcot-Marie-Tooth disease type 4 Uncertain:1

Jan 29, 2016

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

In summary, this is a novel missense change with uncertain impact on protein function. It has been classified as a Variant of Uncertain Significance. Algorithms developed to predict the effect of missense changes on protein structure and function do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0"). This variant is not present in population databases (ExAC no frequency) and has not been reported in the literature in individuals with a PRX-related disease. This sequence change replaces valine with alanine at codon 1435 of the PRX protein (p.Val1435Ala). The valine residue is moderately conserved and there is a small physicochemical difference between valine and alanine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.69
BayesDel_addAF	Uncertain	0.026	T
BayesDel_noAF	Benign	-0.20
CADD	Benign	23
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.45	T
Eigen	Benign	0.085
Eigen_PC	Benign	0.0039
FATHMM_MKL	Benign	0.18	N
LIST_S2	Benign	0.65	T
M_CAP	Benign	0.015	T
MetaRNN	Uncertain	0.72	D
MetaSVM	Benign	-0.97	T
MutationAssessor	Benign	1.0	L
PhyloP100		1.9
PrimateAI	Pathogenic	0.79	T
PROVEAN	Benign	-1.8	N
REVEL	Benign	0.23
Sift	Pathogenic	0.0	D
Sift4G	Benign	0.14	T
Polyphen		0.99	D
Vest4		0.62
MutPred		0.50		Loss of stability (P = 0.0356);
MVP		0.37
MPC		0.42
ClinPred		0.82	D
GERP RS		4.8
Varity_R		0.32
gMVP		0.48
Mutation Taster		=91/9	polymorphism

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

Other links and lift over

dbSNP: rs878855285; hg19: chr19-40899955;