chr20-4686502-G-T

Variant names:

• chr20-4686502-G-T
• rs886056742
• NM_000311.5:c.-21G>T

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_000311.5(PRNP):​c.-21G>T variant causes a 5 prime UTR change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 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: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: PRNP NM_000311.5 5_prime_UTR
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -7.79
• Publications: 0 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: Genomics England PanelApp, Orphanet, Ambry Genetics
• 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: Labcorp Genetics (formerly Invitae), Genomics England PanelApp, Orphanet
• 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 -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.75).

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

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	PRNP	NM_000311.5	MANE Select	c.-21G>T		5_prime_UTR	Exon 1 of 2	NP_000302.1	Q53YK7
	PRNP	NM_001080121.3		c.-16G>T		5_prime_UTR	Exon 1 of 2	NP_001073590.1	P04156-1
	PRNP	NM_001080122.3		c.-12G>T		5_prime_UTR	Exon 1 of 2	NP_001073591.1	P04156-1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	PRNP	ENST00000379440.9	TSL:1 MANE Select	c.-21G>T		5_prime_UTR	Exon 1 of 2	ENSP00000368752.4	P04156-1
	PRNP	ENST00000424424.2	TSL:1	c.-16G>T		5_prime_UTR	Exon 1 of 2	ENSP00000411599.2	P04156-1
	PRNP	ENST00000430350.2	TSL:1	c.-17G>T		5_prime_UTR	Exon 1 of 2	ENSP00000399376.2	P04156-1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 14 Hom.: 0 Cov.: 0 AF XY: 0.00 AC XY: 0 AN XY: 8

African (AFR) AF: 0.00 AC: 0 AN: 2

American (AMR) AC: 0 AN: 0

Ashkenazi Jewish (ASJ) AC: 0 AN: 0

East Asian (EAS) AC: 0 AN: 0

South Asian (SAS) AC: 0 AN: 0

European-Finnish (FIN) AC: 0 AN: 0

Middle Eastern (MID) AC: 0 AN: 0

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 10

Other (OTH) AF: 0.00 AC: 0 AN: 2

GnomAD4 genome Cov.: 32

ClinVar

ClinVar submissions as Germline

Significance: Uncertain significance

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
-	1	-	Inherited prion disease (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.75
CADD	Benign	0.23
DANN	Benign	0.78
PhyloP100		-7.8
PromoterAI		-0.014	Neutral
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.0

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: rs886056742; hg19: chr20-4667148;