rs1553135406

Variant names:

• chr1-55039919-GC-G
• rs1553135406
• NM_174936.4:c.85delC

Variant summary

Our verdict is Pathogenic. Variant got 11 ACMG points: 11P and 0B. PVS1 PM2 PP5

The NM_174936.4(PCSK9):​c.85delC​(p.Arg29ValfsTer15) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: not found (cov: 34)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: PCSK9 NM_174936.4 frameshift
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:1
• Conservation: PhyloP100: 0.328

Genes affected

PCSK9 (HGNC:20001): (proprotein convertase subtilisin/kexin type 9) This gene encodes a member of the subtilisin-like proprotein convertase family, which includes proteases that process protein and peptide precursors trafficking through regulated or constitutive branches of the secretory pathway. The encoded protein undergoes an autocatalytic processing event with its prosegment in the ER and is constitutively secreted as an inactive protease into the extracellular matrix and trans-Golgi network. It is expressed in liver, intestine and kidney tissues and escorts specific receptors for lysosomal degradation. It plays a role in cholesterol and fatty acid metabolism. Mutations in this gene have been associated with autosomal dominant familial hypercholesterolemia. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Feb 2014]

ACMG classification

Verdict is Pathogenic. Variant got 11 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant located near the start codon (<100nt), not predicted to undergo nonsense mediated mRNA decay. There are 54 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 1-55039919-GC-G is Pathogenic according to our data. Variant chr1-55039919-GC-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 496566.We mark this variant Likely_pathogenic, oryginal submissions are: {Uncertain_significance=1, Pathogenic=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
PCSK9	NM_174936.4	c.85delC	p.Arg29ValfsTer15	frameshift_variant	Exon 1 of 12	ENST00000302118.5	NP_777596.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
PCSK9	ENST00000302118.5	c.85delC	p.Arg29ValfsTer15	frameshift_variant	Exon 1 of 12	1	NM_174936.4	ENSP00000303208.5
PCSK9	ENST00000710286.1	c.442delC	p.Arg148ValfsTer15	frameshift_variant	Exon 1 of 12			ENSP00000518176.1
PCSK9	ENST00000673726.1	n.85delC		non_coding_transcript_exon_variant	Exon 1 of 6			ENSP00000501004.1
PCSK9	ENST00000673913.2	n.85delC		non_coding_transcript_exon_variant	Exon 1 of 12			ENSP00000501161.2

Frequencies

GnomAD3 genomes Cov.: 34

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 1415904 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 700006

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: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 34

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Hypercholesterolemia, familial, 1 Pathogenic:1

Mar 01, 2016

Iberoamerican FH Network

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: research

- -

not specified Uncertain:1

Sep 29, 2021

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: PCSK9 c.85delC (p.Arg29ValfsX15) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for Hyporcholesterolemia but not for Hypercholesterolemia. The variant was absent in 175998 control chromosomes. To our knowledge, no occurrence of c.85delC in individuals affected with Familial Hypercholesterolemia and no experimental evidence demonstrating its impact on protein function have been reported. One clinical diagnostic laboratory has submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation and classified the variant as pathogenic. Hyporcholesterolemia may associate with other symptoms (PMID 20626336). However, this variant is likely to confer protection against coronary artery disease due to its LDLC reducing effect (PMID 24507774). Based on the evidence outlined above, the variant was classified as VUS. -

Computational scores

Source: dbNSFP v4.3

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: rs1553135406; hg19: chr1-55505592;