19-11113625-G-C

Variant names:

• chr19-11113625-G-C
• rs879254907
• NM_000527.5:c.1449G>C

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM2 PP3

This summary comes from the ClinGen Evidence Repository: The NM_000527.5(LDLR):c.1449G>C (p.Trp483Cys) variant is classified as Uncertain significance - insufficient evidence for Familial Hypercholesterolemia by applying evidence codes (PM2, PP3) 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.PP3 - REVEL = 0.951.It is above 0.75, so PP3 is Met. LINK:https://erepo.genome.network/evrepo/ui/classification/CA404086103/MONDO:0007750/013

• Frequency: Genomes: not found (cov: 32)
• Consequence: LDLR NM_000527.5 missense
• Clinical Significance: Uncertain significance reviewed by expert panel P:2 U:1
• Conservation: PhyloP100: 9.88
• Publications: 17 publications found

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]

MIR6886 (HGNC:50121): (microRNA 6886) microRNAs (miRNAs) are short (20-24 nt) non-coding RNAs that are involved in post-transcriptional regulation of gene expression in multicellular organisms by affecting both the stability and translation of mRNAs. miRNAs are transcribed by RNA polymerase II as part of capped and polyadenylated primary transcripts (pri-miRNAs) that can be either protein-coding or non-coding. The primary transcript is cleaved by the Drosha ribonuclease III enzyme to produce an approximately 70-nt stem-loop precursor miRNA (pre-miRNA), which is further cleaved by the cytoplasmic Dicer ribonuclease to generate the mature miRNA and antisense miRNA star (miRNA*) products. The mature miRNA is incorporated into a RNA-induced silencing complex (RISC), which recognizes target mRNAs through imperfect base pairing with the miRNA and most commonly results in translational inhibition or destabilization of the target mRNA. The RefSeq represents the predicted microRNA stem-loop. [provided by RefSeq, Sep 2009]

ACMG classification

Our verdict: Uncertain_significance. The variant received 3 ACMG points.

• PM2: For more information check the summary or visit ClinGen Evidence Repository.
• PP3: For more information check the summary or visit ClinGen Evidence Repository.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
LDLR	NM_000527.5	c.1449G>C	p.Trp483Cys	missense_variant	Exon 10 of 18	ENST00000558518.6	NP_000518.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
LDLR	ENST00000558518.6	c.1449G>C	p.Trp483Cys	missense_variant	Exon 10 of 18	1	NM_000527.5	ENSP00000454071.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 35

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Pathogenic:2 Uncertain:1

Revision: reviewed by expert panel

Submissions by phenotype

Hypercholesterolemia, familial, 1 Pathogenic:1 Uncertain:1

-

Laboratorium voor Moleculaire Diagnostiek Experimentele Vasculaire Geneeskunde, Academisch Medisch Centrum

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: research

- -

Apr 29, 2023

ClinGen Familial Hypercholesterolemia Variant Curation Expert Panel

Significance: Uncertain significance

Review Status: reviewed by expert panel

Collection Method: curation

The NM_000527.5(LDLR):c.1449G>C (p.Trp483Cys) variant is classified as Uncertain significance - insufficient evidence for Familial Hypercholesterolemia by applying evidence codes (PM2, PP3) 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. PP3 - REVEL = 0.951. It is above 0.75, so PP3 is Met. -

Familial hypercholesterolemia Pathogenic:1

Nov 29, 2019

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant disrupts the p.Trp483 amino acid residue in LDLR. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 8535447, 17539906, 21382890, 16250003). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. This sequence change replaces tryptophan with cysteine at codon 483 of the LDLR protein (p.Trp483Cys). The tryptophan residue is highly conserved and there is a large physicochemical difference between tryptophan and cysteine. This variant is not present in population databases (ExAC no frequency). This variant has been reported in individual(s) with hypercholesterolemia (PMID: 26892515, Invitae). In at least one individual the data is consistent with the variant being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 440646). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt LDLR protein function. For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.57	D
BayesDel_noAF	Pathogenic	0.58
CADD	Pathogenic	33
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.94	D;.;.;.;.;.
Eigen	Pathogenic	0.88
Eigen_PC	Pathogenic	0.80
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Pathogenic	1.0	D;D;D;D;D;D
M_CAP	Pathogenic	0.94	D
MetaRNN	Pathogenic	0.99	D;D;D;D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	4.1	H;.;.;.;.;H
PhyloP100		9.9
PrimateAI	Uncertain	0.67	T
PROVEAN	Pathogenic	-12	D;D;D;D;D;D
REVEL	Pathogenic	0.95
Sift	Pathogenic	0.0	D;D;D;D;D;D
Sift4G	Pathogenic	0.0010	D;D;D;D;D;D
Polyphen		0.72	P;.;.;.;.;.
Vest4		0.91
MutPred		0.90		Loss of catalytic residue at W483 (P = 0.191);Loss of catalytic residue at W483 (P = 0.191);.;.;.;Loss of catalytic residue at W483 (P = 0.191);
MVP		1.0
MPC		0.93
ClinPred		1.0	D
GERP RS		4.7
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.96
gMVP		0.99
Mutation Taster		=0/100	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		Details are displayed if max score is > 0.2

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

Other links and lift over

dbSNP: rs879254907; hg19: chr19-11224301;