20-4686505-C-T

Position:

chr20-4686505-C-T

Variant summary

Our verdict is Benign. Variant got -14 ACMG points: 0P and 14B. BP4_StrongBP6_ModerateBS1BS2

The NM_000311.5(PRNP):c.-18C>T variant causes a 5 prime UTR premature start codon gain change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00473 in 152,008 control chromosomes in the GnomAD database, including 4 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Benign (★).

Frequency

Genomes: 𝑓 0.0047 ( 4 hom., cov: 32)

Exomes 𝑓: 0.0 ( 0 hom. )

Failed GnomAD Quality Control

Consequence

PRNP
NM_000311.5 5_prime_UTR_premature_start_codon_gain

Scores

Clinical Significance

Benign criteria provided, single submitter B:1

Conservation

PhyloP100: -4.52

Variant links:

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Benign. Variant got -14 ACMG points.

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.69).

BP6

Variant 20-4686505-C-T is Benign according to our data. Variant chr20-4686505-C-T is described in ClinVar as [Benign]. Clinvar id is 338644.Status of the report is criteria_provided_single_submitter, 1 stars.

BS1

Variant frequency is greater than expected in population afr. gnomad4 allele frequency = 0.00473 (719/152008) while in subpopulation AFR AF= 0.0164 (683/41530). AF 95% confidence interval is 0.0154. There are 4 homozygotes in gnomad4. There are 338 alleles in male gnomad4 subpopulation. Median coverage is 32. This position pass quality control queck.

BS2

High Homozygotes in GnomAd4 at 4 AD,AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
PRNP	NM_000311.5 link	c.-18C>T		5_prime_UTR_premature_start_codon_gain_variant	1/2	ENST00000379440.9	NP_000302.1
PRNP	NM_000311.5 link	c.-18C>T		5_prime_UTR_variant	1/2	ENST00000379440.9	NP_000302.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
PRNP	ENST00000379440 link	c.-18C>T		5_prime_UTR_premature_start_codon_gain_variant	1/2	1	NM_000311.5	ENSP00000368752.4		P04156-1
PRNP	ENST00000379440 link	c.-18C>T		5_prime_UTR_variant	1/2	1	NM_000311.5	ENSP00000368752.4		P04156-1

Frequencies

GnomAD3 genomes

AF:

0.00474

AC:

720

AN:

151900

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0165

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00164

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.000207

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000147

Gnomad OTH

AF:

0.00431

GnomAD4 exome

Data not reliable, filtered out with message: AC0

AF:

0.00

AC:

AN:

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

Gnomad4 AFR exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.00473

AC:

719

AN:

152008

Hom.:

Cov.:

AF XY:

0.00455

AC XY:

338

AN XY:

74322

show subpopulations

Gnomad4 AFR

AF:

0.0164

Gnomad4 AMR

AF:

0.00164

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.000207

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000147

Gnomad4 OTH

AF:

0.00426

Alfa

AF:

0.000140

Hom.:

Bravo

AF:

0.00525

Asia WGS

AF:

0.000881

AC:

AN:

3418

ClinVar

Significance: Benign

Submissions summary: Benign:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Inherited prion disease

Benign:1

Benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 12, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.69

CADD

Benign

2.6

DANN

Benign

0.94

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.0

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.020

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over