chr19-11120191-C-T

Position:

• chr19-11120191-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM2 PP3 PP4 PS4_Supporting

This summary comes from the ClinGen Evidence Repository: The NM_000527.5(LDLR):c.1945C>T (p.Pro649Ser) variant is classified as Uncertain significance - insufficient evidence for Familial Hypercholesterolemia by applying ACMG/AMP evidence codes PM2, PP3, PP4 and PS4_Supporting as defined by the ClinGen Familial Hypercholesterolemia Expert Panel LDLR-specific variant curation guidelines (specification version 1.2) on 28 October 2024.The supporting evidence is as follows:PM2: This variant is absent from gnomAD (gnomAD v4.1.0).PP3: REVEL = 0.766. PS4_Supporting, PP4: Variant meets PM2 and is identified in at least 4 index cases who fulfill criteria for FH, after alternative causes of high cholesterol were excluded (1 case with probable FH by Simon Broome criteria and 1 case with DLCN score >=6 from Centre de Génétique Moléculaire et Chromosomique, Unité de génétique de l'Obésité et des Dyslipidémies, APHP.Sorbonne Université, Hôpital de la Pitié-Salpêtrière, France; 1 case with DLCN score >=6 from Research Lab of Molecular Genetics of Lipid Metabolism, Italy - Prof. M. Arca; 1 case with DLCN score >=6 from Meshkov et al 2021, PMID 33418990). LINK:https://erepo.genome.network/evrepo/ui/classification/CA10585688/MONDO:0007750/013

• Frequency: Genomes: not found (cov: 33)
• Consequence: LDLR NM_000527.5 missense
• Clinical Significance: Uncertain significance reviewed by expert panel P:2 U:1
• Conservation: PhyloP100: 3.36

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 Uncertain_significance. Variant got 5 ACMG points.

• PS4: For more information check the summary or visit ClinGen Evidence Repository.
• PM2: For more information check the summary or visit ClinGen Evidence Repository.
• PP3: For more information check the summary or visit ClinGen Evidence Repository.
• PP4: For more information check the summary or visit ClinGen Evidence Repository.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
LDLR	NM_000527.5	c.1945C>T	p.Pro649Ser	missense_variant	13/18	ENST00000558518.6	NP_000518.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
LDLR	ENST00000558518.6	c.1945C>T	p.Pro649Ser	missense_variant	13/18	1	NM_000527.5	ENSP00000454071.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Pathogenic:2 Uncertain:1

Revision: reviewed by expert panel

Submissions by phenotype

Hypercholesterolemia, familial, 1 Pathogenic:1

Likely pathogenic, criteria provided, single submitter

literature only

LDLR-LOVD, British Heart Foundation

Mar 25, 2016

- -

Familial hypercholesterolemia Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Mar 23, 2023

This variant is not present in population databases (gnomAD no frequency). For these reasons, this variant has been classified as Pathogenic. 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. ClinVar contains an entry for this variant (Variation ID: 252121). This missense change has been observed in individuals with clinical features of familial hypercholesterolemia (PMID: 20809525; Invitae). It has also been observed to segregate with disease in related individuals. This sequence change replaces proline, which is neutral and non-polar, with serine, which is neutral and polar, at codon 649 of the LDLR protein (p.Pro649Ser). -

Cardiovascular phenotype Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Jul 19, 2023

The p.P649S variant (also known as c.1945C>T), located in coding exon 13 of the LDLR gene, results from a C to T substitution at nucleotide position 1945. The proline at codon 649 is replaced by serine, an amino acid with similar properties. This alteration has been reported in familial hypercholesterolemia (FH) cohorts (Marduel M et al. Hum Mutat, 2010 Nov;31:E1811-24; Meshkov A et al. Genes (Basel), 2021 Jan;12:). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.82
BayesDel_addAF	Pathogenic	0.37	D
BayesDel_noAF	Pathogenic	0.29
CADD	Uncertain	24
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.92	D;.;.;.;.;.
Eigen	Uncertain	0.61
Eigen_PC	Uncertain	0.43
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.95	D;D;D;D;D;D
M_CAP	Pathogenic	0.96	D
MetaRNN	Pathogenic	0.97	D;D;D;D;D;D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	3.8	H;.;.;.;.;H
PrimateAI	Uncertain	0.54	T
PROVEAN	Pathogenic	-5.9	D;D;D;D;D;D
REVEL	Pathogenic	0.77
Sift	Uncertain	0.0070	D;D;D;D;D;D
Sift4G	Uncertain	0.0060	D;D;D;D;D;D
Polyphen		0.96	D;.;.;.;.;.
Vest4		0.65
MutPred		0.80		Gain of sheet (P = 0.1451);Gain of sheet (P = 0.1451);.;.;.;Gain of sheet (P = 0.1451);
MVP		1.0
MPC		0.79
ClinPred		0.98	D
GERP RS		5.4
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.73
gMVP		0.99

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: rs879255080; hg19: chr19-11230867;