rs757940549

Positions:

• chr16-29814420-G-T

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PM1 PM2 PM5 PP3

The NM_145239.3(PRRT2):​c.967G>T​(p.Gly323Trp) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000206 in 1,455,878 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 (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G323E) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: PRRT2 NM_145239.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.28

Genes affected

PRRT2 (HGNC:30500): (proline rich transmembrane protein 2) This gene encodes a transmembrane protein containing a proline-rich domain in its N-terminal half. Studies in mice suggest that it is predominantly expressed in brain and spinal cord in embryonic and postnatal stages. Mutations in this gene are associated with episodic kinesigenic dyskinesia-1. Alternatively spliced transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jan 2012]

MVP-DT (HGNC:56029): (MVP divergent transcript)

ACMG classification

Verdict is Likely_pathogenic. Variant got 7 ACMG points.

• PM1: In a hotspot region, there are 5 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 9 uncertain in NM_145239.3
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chrnull-null-null-null is described in UniProt as null.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.803

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
PRRT2	NM_145239.3	c.967G>T	p.Gly323Trp	missense_variant	3/4	ENST00000358758.12

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
PRRT2	ENST00000358758.12	c.967G>T	p.Gly323Trp	missense_variant	3/4	1	NM_145239.3	P1
MVP-DT	ENST00000569039.5	n.246-4247C>A		intron_variant, non_coding_transcript_variant		2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.0000123 AC: 3 AN: 243486 Hom.: 0 AF XY: 0.00000760 AC XY: 1 AN XY: 131516

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: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000273

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000206 AC: 3 AN: 1455878 Hom.: 0 Cov.: 35 AF XY: 0.00000138 AC XY: 1 AN XY: 724138

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000270

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ExAC AF: 0.0000165 AC: 2

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Episodic kinesigenic dyskinesia Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Feb 21, 2020

This variant is present in population databases (rs757940549, ExAC 0.003%). This sequence change replaces glycine with tryptophan at codon 323 of the PRRT2 protein (p.Gly323Trp). The glycine residue is highly conserved and there is a large physicochemical difference between glycine and tryptophan. This variant has not been reported in the literature in individuals with PRRT2-related disease. 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. 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: "Probably Damaging"; Align-GVGD: "Class C15"). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.98
BayesDel_addAF	Pathogenic	0.20	D
BayesDel_noAF	Uncertain	0.12
CADD	Pathogenic	33
DANN	Uncertain	1.0
Eigen	Uncertain	0.53
Eigen_PC	Uncertain	0.47
FATHMM_MKL	Uncertain	0.87	D
LIST_S2	Benign	0.33	T;T;T
M_CAP	Pathogenic	0.45	D
MetaRNN	Pathogenic	0.80	D;D;D
MutationTaster	Benign	1.0	D;D;D
ClinPred		0.63	D
GERP RS		3.7

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: rs757940549; hg19: chr16-29825741;