rs773064328

Positions:

• chr19-11111582-T-C
• chr19-11111582-T-G

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PM1 PM2 PM5 PP3_Strong PP5_Very_Strong

The NM_000527.5(LDLR):​c.1129T>C​(p.Cys377Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. C377G) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 31)
• Consequence: LDLR NM_000527.5 missense
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 7.83

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 Pathogenic. Variant got 18 ACMG points.

• PM1: In a disulfide_bond (size 13) in uniprot entity LDLR_HUMAN there are 23 pathogenic changes around while only 2 benign (92%) in NM_000527.5
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr19-11111582-T-G is described in Lovd as [Likely_pathogenic].
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.996
• PP5: Variant 19-11111582-T-C is Pathogenic according to our data. Variant chr19-11111582-T-C is described in ClinVar as [Pathogenic]. Clinvar id is 1727785.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr19-11111582-T-C is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
LDLR	NM_000527.5	c.1129T>C	p.Cys377Arg	missense_variant	8/18	ENST00000558518.6	NP_000518.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
LDLR	ENST00000558518.6	c.1129T>C	p.Cys377Arg	missense_variant	8/18	1	NM_000527.5	ENSP00000454071	P3

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251338 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135878

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000880

Gnomad OTH exome AF: 0.00

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 31

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Cardiovascular phenotype Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Apr 24, 2020

The p.C377R pathogenic mutation (also known as c.1129T>C), located in coding exon 8 of the LDLR gene, results from a T to C substitution at nucleotide position 1129. The cysteine at codon 377, located in the EGF-like 2 domain, is replaced by arginine, an amino acid with highly dissimilar properties. Pathogenic LDLR mutations that result in the substitution or generation of cysteine residues within the cysteine-rich LDLR class A repeats and EGF-like domains are common in familial hypercholesterolemia (FH) (Villéger L. Hum Mutat. 2002;20(2):81-7). This particular cysteine alteration has been detected in probands from an FH cohort, and in a myocardial infarction cohort (Do R et al. Nature, 2015 Feb;518:102-6; Gabová D et al. Physiol Res, 2017 03;66:75-84). Internal structural analysis indicates this alteration eliminates a disulfide bond critical for the structural integrity of the EGF-like 2 domain (Ambry internal data). In addition, other variants affecting this codon (including but not limited to p.C377S, c.1130G>C and p.C377Y, c.1130G>A) have also been reported in association with FH (Bertolini S et al. Atherosclerosis, 2013 Apr;227:342-8; Gabová D et al. Physiol Res, 2017 03;66:75-84). Based on the supporting evidence, this alteration is interpreted as a disease-causing mutation. -

Familial hypercholesterolemia Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Aug 17, 2023

This sequence change replaces cysteine, which is neutral and slightly polar, with arginine, which is basic and polar, at codon 377 of the LDLR protein (p.Cys377Arg). This variant is present in population databases (rs773064328, gnomAD 0.0009%). This missense change has been observed in individuals with clinical features of LDLR-related conditions and/or familial hypercholesterolemia (PMID: 25487149, 27824480). ClinVar contains an entry for this variant (Variation ID: 1727785). 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. This variant affects a cysteine residue located within an LDLRA or epidermal-growth-factor (EGF)-like domains of the LDLR protein. Cysteine residues in these domains have been shown to be involved in the formation of disulfide bridges, which are critical for protein structure and stability (PMID: 7548065, 7603991, 7979249). In addition, missense substitutions within the LDLRA and EGF-like domains affecting cysteine residues are overrepresented among patients with hypercholesterolemia (PMID: 18325082). This variant disrupts the p.Cys377 amino acid residue in LDLR. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 9767373, 23680767, 24722143, 27824480, 29693183, 32770674). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.98
BayesDel_addAF	Pathogenic	0.58	D
BayesDel_noAF	Pathogenic	0.60
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.98	D;.;.;.;.;.
Eigen	Pathogenic	0.86
Eigen_PC	Pathogenic	0.70
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.99	D;D;D;D;D;D
M_CAP	Pathogenic	0.97	D
MetaRNN	Pathogenic	1.0	D;D;D;D;D;D
MetaSVM	Pathogenic	0.99	D
MutationAssessor	Pathogenic	4.9	H;.;.;.;.;H
MutationTaster	Benign	1.0	D;D;D;D;D;D;D
PrimateAI	Uncertain	0.65	T
PROVEAN	Pathogenic	-11	D;D;D;D;D;D
REVEL	Pathogenic	0.98
Sift	Pathogenic	0.0	D;D;D;D;D;D
Sift4G	Pathogenic	0.0	D;D;D;D;D;D
Polyphen		1.0	D;.;.;.;.;.
Vest4		0.97
MutPred		0.97		Loss of methylation at K376 (P = 0.0184);Loss of methylation at K376 (P = 0.0184);.;.;.;Loss of methylation at K376 (P = 0.0184);
MVP		1.0
MPC		1.1
ClinPred		1.0	D
GERP RS		4.5
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.98
gMVP		1.0

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: rs773064328; hg19: chr19-11222258;