19-11089448-T-C

Position:

• chr19-11089448-T-C

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NR_163945.1(LDLR-AS1):​n.212A>G variant causes a non coding transcript exon change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000524 in 762,776 control chromosomes in the GnomAD database, with no homozygous occurrence. 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: 0.0000052 (0 hom.)
• Consequence: LDLR-AS1 NR_163945.1 non_coding_transcript_exon
• Clinical Significance: Uncertain significance reviewed by expert panel P:1 U:5
• Conservation: PhyloP100: 0.132

Genes affected

LDLR-AS1 (HGNC:):

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 Likely_benign. Variant got -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.48).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
LDLR-AS1	NR_163945.1	n.212A>G		non_coding_transcript_exon_variant	1/1
LDLR	NM_000527.5			upstream_gene_variant		ENST00000558518.6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
LDLR	ENST00000558518.6			upstream_gene_variant		1	NM_000527.5	P3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000524 AC: 4 AN: 762776 Hom.: 0 Cov.: 10 AF XY: 0.00000504 AC XY: 2 AN XY: 396840

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: 0.00000793

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Pathogenic:1 Uncertain:5

Revision: reviewed by expert panel

Submissions by phenotype

Hypercholesterolemia, familial, 1 Pathogenic:1 Uncertain:3

Uncertain significance, criteria provided, single submitter	curation;literature only	Cardiovascular Research Group, Instituto Nacional de Saude Doutor Ricardo Jorge	Mar 01, 2016	- -
Uncertain significance, criteria provided, single submitter	clinical testing	All of Us Research Program, National Institutes of Health	Nov 28, 2022	This variant is located in the TATA box in the promoter region of the LDLR gene. A functional study has shown that this variant decreases the promoter activity by 36% (PMID: 25248394). This variant has been reported in an individual affected with familial hypercholesterolemia (PMID: 22881376). This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -
Likely pathogenic, criteria provided, single submitter	literature only	LDLR-LOVD, British Heart Foundation	Mar 25, 2016	- -
Uncertain significance, reviewed by expert panel	curation	ClinGen Familial Hypercholesterolemia Variant Curation Expert Panel	Feb 10, 2022	The NM_000527.5 (LDLR): c.-101T>C variant is classified as Uncertain significance - insufficient evidence for Familial Hypercholesterolemia by applying evidence codes (PM2, PP4) as defined by the ClinGen Familial Hypercholesterolemia Expert Panel LDLR-specific variant curation guidelines (https://doi.org/10.1016/j.gim.2021.09.012). The supporting evidence is as follows: PM2 Met: This variant is absent in gnomAD (gnomAD v2.1.1). PP4 Met: Variant meets PM2 and is identified in 1 index case who fulfil Simon Broome criteria for FH diagnosis (British Heart Foundation Laboratories, Centre for Cardiovascular Genetics, Institute of Cardiovascular Sciences, University College London, London, UK, PMID 22881376). PS3 not met: Heterologous cells (Huh7) were used in luciferase assay (level 3 functional assay), and have shown 64% reporter gene expression, which is greater than 50% compared to wild-type (Khamis et al 2015, Centre for Cardiovascular Genetics, British Heart Foundation Laboratories, Institute Cardiovascular Science, University College London Medicine School, London, UK, PMID 25248394). -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Quest Diagnostics Nichols Institute San Juan Capistrano

Jan 13, 2021

- -

Familial hypercholesterolemia Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Color Diagnostics, LLC DBA Color Health

Oct 24, 2022

This variant is located in the TATA box in the promoter region of the LDLR gene. A functional study has shown that this variant decreases the promoter activity by 36% (PMID: 25248394). This variant has been reported in an individual affected with familial hypercholesterolemia (PMID: 22881376). This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.48
CADD	Benign	7.7
DANN	Benign	0.73

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: rs747068848; hg19: chr19-11200124; COSMIC: COSV52943610; COSMIC: COSV52943610;