rs879254372

Variant names:

• chr19-11089411-T-C
• rs879254372
• NR_163945.1:n.249A>G

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PM2 BP4

The NR_163945.1(LDLR-AS1):​n.249A>G variant causes a non coding transcript exon 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: 0.0000019 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: LDLR-AS1 NR_163945.1 non_coding_transcript_exon
• Clinical Significance: Uncertain significance reviewed by expert panel P:1 U:3
• Conservation: PhyloP100: 0.859

Genes affected

LDLR-AS1 (HGNC:54407): (LDLR antisense RNA 1) This gene represents a regulatory lncRNA that overlaps the 5' UTR and coding sequence of the LDLR (low density lipoprotein receptor) gene. This lncRNA overlaps LDLR in the antisense orientation, and has been shown to downregulate production of the low density lipoprotein receptor. [provided by RefSeq, Jul 2019]

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 Uncertain_significance. Variant got 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.18).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
LDLR	NM_000527.5	c.-138T>C		upstream_gene_variant		ENST00000558518.6	NP_000518.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
LDLR	ENST00000558518.6	c.-138T>C		upstream_gene_variant		1	NM_000527.5	ENSP00000454071.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Data not reliable, filtered out with message: AS_VQSR AF: 0.00000192 AC: 1 AN: 519692 Hom.: 0 Cov.: 7 AF XY: 0.00000367 AC XY: 1 AN XY: 272170

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: 0.00000312

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Pathogenic:1 Uncertain:3

Revision: reviewed by expert panel

Submissions by phenotype

Hypercholesterolemia, familial, 1 Pathogenic:1 Uncertain:2

Oct 28, 2022

ClinGen Familial Hypercholesterolemia Variant Curation Expert Panel

Significance: Uncertain significance

Review Status: reviewed by expert panel

Collection Method: curation

The NM_000527.4(LDLR):c.-138T>C variant is classified as Uncertain significance - insufficient evidence for Familial Hypercholesterolemia by applying evidence codes (PM2, PS3_supporting) as defined by the ClinGen Familial Hypercholesterolemia Expert Panel LDLR-specific variant curation guidelines (https://doi.org/10.1101/2021.03.17.21252755). The supporting evidence is as follows: PM2_Met : This variant is absent from gnomAD (v.2.1.1). PS3_supporting Met: Level 3 Assay: Luciferase Assay + COS cells. The variant T-45C (Hobbs' numbering: -45T>C) is in the proximal Sp1 binding site in repeat 3 of the 42 bp region of the promoter required for steroldependent regulation of transcription. In 1995 Sun et al ( PMID: 8589690) reported that the variant reduced transcriptional activity to approximately 43% of normal in the presence, and 25% in the absence of sterols in the medium (repressing variant). -

Mar 25, 2016

LDLR-LOVD, British Heart Foundation

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: literature only

- -

Mar 01, 2016

Cardiovascular Research Group, Instituto Nacional de Saude Doutor Ricardo Jorge

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: curation;literature only

- -

not provided Uncertain:1

Sep 08, 2022

Quest Diagnostics Nichols Institute San Juan Capistrano

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant has not been described in online databases. It also has not been reported in large, multi-ethnic general populations (http://gnomad.broadinstitute.org). In the published literature, the variant has been reported in an affected individual with familial hypercholesterolemia (PMID: 8589690 (1995)). Functional studies found that this variant reduced promotor activity compared to wild type (PMIDs: 8589690 (1995), 25248394 (2015), 31395865 (2019)). Based on the available information, we are unable to determine the clinical significance of this variant. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.18
CADD	Benign	17
DANN	Benign	0.89

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: rs879254372; hg19: chr19-11200087;