NM_000311.5:c.678C>G

Variant names:

• chr20-4699898-C-G
• rs398122414
• NM_000311.5:c.678C>G

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PVS1_Strong PM2

The NM_000311.5(PRNP):​c.678C>G​(p.Tyr226*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000658 in 152,004 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
• Consequence: PRNP NM_000311.5 stop_gained
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.316
• Publications: 27 publications found

Genes affected

PRNP (HGNC:9449): (prion protein (Kanno blood group)) The protein encoded by this gene is a membrane glycosylphosphatidylinositol-anchored glycoprotein that tends to aggregate into rod-like structures. The encoded protein contains a highly unstable region of five tandem octapeptide repeats. This gene is found on chromosome 20, approximately 20 kbp upstream of a gene which encodes a biochemically and structurally similar protein to the one encoded by this gene. Mutations in the repeat region as well as elsewhere in this gene have been associated with Creutzfeldt-Jakob disease, fatal familial insomnia, Gerstmann-Straussler disease, Huntington disease-like 1, and kuru. An overlapping open reading frame has been found for this gene that encodes a smaller, structurally unrelated protein, AltPrp. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Nov 2014]

PRNP Gene-Disease associations (from GenCC):

• Gerstmann-Straussler-Scheinker syndrome

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Ambry Genetics, Genomics England PanelApp, Orphanet
• Huntington disease-like 1

  Inheritance: AD Classification: STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, Orphanet
• inherited Creutzfeldt-Jakob disease

  Inheritance: AD Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae), Genomics England PanelApp
• familial Alzheimer-like prion disease

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• fatal familial insomnia

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• PrP systemic amyloidosis

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_pathogenic. The variant received 6 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. Fraction of 0.11 CDS is truncated, and there are 2 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000311.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	PRNP	NM_000311.5	MANE Select	c.678C>G	p.Tyr226*	stop_gained	Exon 2 of 2	NP_000302.1
	PRNP	NM_001080121.3		c.678C>G	p.Tyr226*	stop_gained	Exon 2 of 2	NP_001073590.1
	PRNP	NM_001080122.3		c.678C>G	p.Tyr226*	stop_gained	Exon 2 of 2	NP_001073591.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	PRNP	ENST00000379440.9	TSL:1 MANE Select	c.678C>G	p.Tyr226*	stop_gained	Exon 2 of 2	ENSP00000368752.4
	PRNP	ENST00000424424.2	TSL:1	c.678C>G	p.Tyr226*	stop_gained	Exon 2 of 2	ENSP00000411599.2
	PRNP	ENST00000430350.2	TSL:1	c.678C>G	p.Tyr226*	stop_gained	Exon 2 of 2	ENSP00000399376.2

Frequencies

GnomAD3 genomes AF: 0.00000658 AC: 1 AN: 152004 Hom.: 0 Cov.: 32

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: 0.0000147

Gnomad OTH AF: 0.00

GnomAD4 exome Cov.: 32

GnomAD4 genome AF: 0.00000658 AC: 1 AN: 152004 Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1 AN XY: 74238

African (AFR) AF: 0.00 AC: 0 AN: 41380

American (AMR) AF: 0.00 AC: 0 AN: 15248

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3468

East Asian (EAS) AF: 0.00 AC: 0 AN: 5172

South Asian (SAS) AF: 0.00 AC: 0 AN: 4816

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10590

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 68010

Other (OTH) AF: 0.00 AC: 0 AN: 2092

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.54	D
BayesDel_noAF	Uncertain	0.020
CADD	Pathogenic	32
DANN	Benign	0.90
Eigen	Benign	-0.27
Eigen_PC	Benign	-0.59
FATHMM_MKL	Benign	0.14	N
PhyloP100		0.32
Vest4		0.83
GERP RS		2.0
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Mutation Taster		=9/191	disease causing

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: rs398122414; hg19: chr20-4680544;