19-11089413-C-G

Position:

• chr19-11089413-C-G

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 6P and 1B. PM2 PP5_Strong BP4

The NR_163945.1(LDLR-AS1):​n.247G>C variant causes a non coding transcript exon change. 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)
• Consequence: LDLR-AS1 NR_163945.1 non_coding_transcript_exon
• Clinical Significance: Uncertain significance reviewed by expert panel P:2 U:2
• Conservation: PhyloP100: 3.66

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 Uncertain_significance. Variant got 5 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 19-11089413-C-G is Pathogenic according to our data. Variant chr19-11089413-C-G is described in ClinVar as [Uncertain_significance]. Clinvar id is 250954.Status of the report is reviewed_by_expert_panel, 3 stars. We mark this variant Likely_pathogenic, oryginal submissions are: {Uncertain_significance=2, Likely_pathogenic=2}. Variant chr19-11089413-C-G is described in Lovd as [Likely_pathogenic].
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.14). . Strength limited to SUPPORTING due to the PP5.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
LDLR	NM_000527.5	c.-136C>G		upstream_gene_variant		ENST00000558518.6	NP_000518.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
LDLR	ENST00000558518.6	c.-136C>G		upstream_gene_variant		1	NM_000527.5	ENSP00000454071.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 7

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Pathogenic:2 Uncertain:2

Revision: reviewed by expert panel

Submissions by phenotype

Hypercholesterolemia, familial, 1 Pathogenic:1 Uncertain:2

Uncertain significance, criteria provided, single submitter	research	Fundacion Hipercolesterolemia Familiar	Mar 01, 2016	- -
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	Aug 28, 2022	The NM_000527.4(LDLR):c.-136C>G variant is classified as Uncertain significance - insufficient evidence for Familial Hypercholesterolemia by applying evidence codes PM2, PS3_Moderate and 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 - This variant is absent from gnomAD (gnomAD v2.1.1), so PM2 is met. PS3_moderate - 2 Level 3 FS: (1) De Castro-Orós et al. 2011 (PMID: 21538688): Heterologous cells (HepG2), luciferase assays - results: 12% reporter gene expression (2) Kircher et al. 2019 (PMID: 31395865): saturation mutagenesis in HepG2 cells, luciferase high throughput study - results: 16% and 11% luciferase expression --- in both studies, transcription levels are below 50% of wild-type, so PS3_Moderate is met. PP4 - Variant meets PM2 and is identified in 1 index case who fulfills DLCN >6 criteria for FH from PMID: 21538688, after alternative causes of high cholesterol were excluded. -

Familial hypercholesterolemia Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Sep 17, 2023

This variant occurs in a non-coding region of the LDLR gene. It does not change the encoded amino acid sequence of the LDLR protein. This variant is not present in population databases (gnomAD no frequency). This variant has been observed in individuals with clinical features of familial hypercholesterolemia (PMID: 21538688; Invitae). ClinVar contains an entry for this variant (Variation ID: 250954). Algorithms developed to predict the effect of variants on protein structure and function are not available or were not evaluated for this variant. Experimental studies have shown that this variant affects LDLR function (PMID: 21538688). This variant disrupts the -136C nucleotide in the LDLR gene. Other variant(s) that disrupt this nucleotide have been determined to be pathogenic (PMID: 7937987, 8664911, 15199436, 15359125, 16250003). This suggests that this nucleotide is clinically significant, and that variants that disrupt this position are likely to be disease-causing. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.14
CADD	Benign	21
DANN	Benign	0.93

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: rs879254374; hg19: chr19-11200089;