rs879254471

Positions:

• chr19-11105219-G-A
• chr19-11105219-G-T

Variant summary

Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PVS1_Strong PM2 PP5_Very_Strong

The NM_000527.5(LDLR):​c.314-1G>A variant causes a splice acceptor, intron change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: LDLR NM_000527.5 splice_acceptor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:10
• Conservation: PhyloP100: 5.08

Genes affected

LDLR (HGNC:6547): (low density lipoprotein receptor) The low density lipoprotein receptor (LDLR) gene family consists of cell surface proteins involved in receptor-mediated endocytosis of specific ligands. The encoded protein is normally bound at the cell membrane, where it binds low density lipoprotein/cholesterol and is taken into the cell. Lysosomes release the cholesterol, which is made available for repression of microsomal enzyme 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase, the rate-limiting step in cholesterol synthesis. At the same time, a reciprocal stimulation of cholesterol ester synthesis takes place. Mutations in this gene cause the autosomal dominant disorder, familial hypercholesterolemia. Alternate splicing results in multiple transcript variants.[provided by RefSeq, May 2022]

ACMG classification

Verdict is Pathogenic. Variant got 14 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.14711575 fraction of the gene. No cryptic splice site detected. Exon removal is inframe change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 19-11105219-G-A is Pathogenic according to our data. Variant chr19-11105219-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 251148.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr19-11105219-G-A is described in Lovd as [Pathogenic]. Variant chr19-11105219-G-A is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
LDLR	NM_000527.5	c.314-1G>A		splice_acceptor_variant, intron_variant		ENST00000558518.6	NP_000518.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
LDLR	ENST00000558518.6	c.314-1G>A		splice_acceptor_variant, intron_variant		1	NM_000527.5	ENSP00000454071.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:10

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hypercholesterolemia, familial, 1 Pathogenic:5

Pathogenic, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Aug 31, 2022	- -
Likely pathogenic, criteria provided, single submitter	literature only	LDLR-LOVD, British Heart Foundation	Mar 25, 2016	- -
Pathogenic, criteria provided, single submitter	clinical testing	All of Us Research Program, National Institutes of Health	Oct 23, 2023	This variant causes a G to A nucleotide substitution at the -1 position of intron 3 of the LDLR gene. Splice site prediction tools suggest that this variant may have a significant impact on RNA splicing. A functional RNA study using lymphocytes derived from a heterozygous carrier individual has shown that this variant causes abnormal splicing, leading to skipping of exon 4 (PMID: 19208450). Additionally, flow cytometry analysis of these carrier-derived lymphocytes has shown that this variant causes a significant reduction in residual LDLR activity (PMID: 19208450). This variant has been reported in more than 10 individuals affected with familial hypercholesterolemia (PMID: 9452078, 11810272, 20506408, 21382890, 30795984, 31048103, 36604244). This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). Loss of LDLR function is a known mechanism of disease (clinicalgenome.org). Based on the available evidence, this variant is classified as Pathogenic. -
Pathogenic, criteria provided, single submitter	curation;literature only	Cardiovascular Research Group, Instituto Nacional de Saude Doutor Ricardo Jorge	Mar 01, 2016	- -
Pathogenic, no assertion criteria provided	research	Laboratorium voor Moleculaire Diagnostiek Experimentele Vasculaire Geneeskunde, Academisch Medisch Centrum	-	- -

not provided Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Oct 04, 2022	Not observed at significant frequency in large population cohorts (gnomAD); Canonical splice site variant expected to result in aberrant splicing and loss of adjacent in-frame exon; Published functional studies using flow cytometry in patient cells show abnormal splicing leading to skipping of exon 4 or retention of intron 3 (Holla et al., 2009); Deletions involving coding exons of this gene are a known mechanism of disease (HGMD); This variant is associated with the following publications: (PMID: 22294733, 25911074, 11810272, 20506408, 21382890, 22390909, 30795984, 31048103, 9452078, 19208450) -
Pathogenic, criteria provided, single submitter	clinical testing	Molecular Diagnostic Laboratory for Inherited Cardiovascular Disease, Montreal Heart Institute	Jun 17, 2019	- -

Familial hypercholesterolemia Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Jan 20, 2023	For these reasons, this variant has been classified as Pathogenic. This variant disrupts the p.Cys109 amino acid residue in LDLR. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 9544745, 11313767, 22883975, 24956927). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. Studies have shown that disruption of this splice site results in skipping of exon 4, but is expected to preserve the integrity of the reading-frame (PMID: 19208450). ClinVar contains an entry for this variant (Variation ID: 251148). This variant is also known as S285L. Disruption of this splice site has been observed in individuals with familial hypercholesterolemia (PMID: 9452078, 31048103). This variant is not present in population databases (gnomAD no frequency). This sequence change affects an acceptor splice site in intron 3 of the LDLR gene. RNA analysis indicates that disruption of this splice site induces altered splicing and likely results in a shortened protein product. -
Pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Jan 10, 2022	Variant summary: LDLR c.314-1G>A alters a conserved nucleotide located in a canonical splice-site and is predicted to affect mRNA splicing resulting in a significantly altered protein due to either exon skipping, shortening, or inclusion of intronic material. Several computational tools predict a significant impact on normal splicing: Four predict the variant abolishes the canonical 3' splice acceptor site. At least one publication reports experimental evidence that this variant affects mRNA splicing resulting in skipping of exon 4 (example, Holla_2009). The variant was absent in 249626 control chromosomes. c.314-1G>A has been reported in the literature in individuals affected with Familial Hypercholesterolemia (example, Lombardi_1998, Luirink_2019, Fouchier_2001). At least one publication reports experimental evidence evaluating an impact on protein function (example, Holla_2009). The most pronounced variant effect results in decrease in LDL-receptor activity (approximately 41% of wild type), decrease in LDL internalization (approximately 30% of wild type) and decrease in cell surface LDL-receptor levels (approximately 50% of wild type). Four clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as pathogenic/likely pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -

Cardiovascular phenotype Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

May 24, 2021

The c.314-1G>A pathogenic mutation, results from a G to A one nucleotide upstream from coding exon 4 of the LDLR gene. This alteration has been reported in familial hypercholestremia (FH) patients (Huijgen et al 2010; Hum Mut 31(6):752-60; Lombardi P et al. Hum Mutat, 1998;Suppl 1:S172-4; Luirink IK et al. Atherosclerosis, 2019 06;285:87-92). This alteration has also been shown to have an impact on protein function (Holla ØL et al. Mol Genet Metab, 2009 Apr;96:245-52). Alterations that disrupt the canonical splice site are expected to cause aberrant splicing, resulting in an abnormal protein or a transcript that is subject to nonsense-mediated mRNA decay. Based on the supporting evidence, this alteration is interpreted as a disease-causing mutation. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.14
CADD	Pathogenic	28
DANN	Uncertain	0.99
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.82
FATHMM_MKL	Pathogenic	1.0	D
GERP RS		5.3
RBP_binding_hub_radar		0.77
RBP_regulation_power_radar		2.7

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.92
SpliceAI score (max)		0.99		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.27		Position offset: 9
DS_AL_spliceai		0.99		Position offset: 1

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs879254471; hg19: chr19-11215895;