chr20-4699400-T-C

Variant names:

• chr20-4699400-T-C
• rs1386720703
• NM_000311.5:c.180T>C

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 2P and 5B. PM2 BP4_Strong BP7

The NM_000311.5(PRNP):​c.180T>C​(p.Pro60Pro) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,456,948 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: PRNP NM_000311.5 synonymous
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -0.711
• Publications: 1 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_benign. The variant received -3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.79).
• BP7: Synonymous conserved (PhyloP=-0.711 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
PRNP	NM_000311.5	c.180T>C	p.Pro60Pro	synonymous_variant	Exon 2 of 2	ENST00000379440.9	NP_000302.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
PRNP	ENST00000379440.9	c.180T>C	p.Pro60Pro	synonymous_variant	Exon 2 of 2	1	NM_000311.5	ENSP00000368752.4
PRNP	ENST00000424424.2	c.180T>C	p.Pro60Pro	synonymous_variant	Exon 2 of 2	1		ENSP00000411599.2
PRNP	ENST00000430350.2	c.180T>C	p.Pro60Pro	synonymous_variant	Exon 2 of 2	1		ENSP00000399376.2
PRNP	ENST00000457586.2	c.180T>C	p.Pro60Pro	synonymous_variant	Exon 2 of 2	1		ENSP00000415284.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1456948 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 724600

African (AFR) AF: 0.00 AC: 0 AN: 33156

American (AMR) AF: 0.00 AC: 0 AN: 44510

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26078

East Asian (EAS) AF: 0.00 AC: 0 AN: 39498

South Asian (SAS) AF: 0.00 AC: 0 AN: 85512

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53234

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5494

European-Non Finnish (NFE) AF: 0.00000180 AC: 2 AN: 1109382

Other (OTH) AF: 0.00 AC: 0 AN: 60084

GnomAD4 genome Cov.: 32

Alfa AF: 0.0000301 Hom.: 0

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Spongiform encephalopathy with neuropsychiatric features Uncertain:1

Jun 26, 2016

Undiagnosed Diseases Network, NIH

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.79
CADD	Benign	7.0
DANN	Benign	0.56
PhyloP100		-0.71

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: rs1386720703; hg19: chr20-4680046; COSMIC: COSV65173769;