19-11105333-T-C

Position:

• chr19-11105333-T-C

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.427T>C​(p.Cys143Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,608 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. C143F) has been classified as Pathogenic.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: LDLR NM_000527.5 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:7
• Conservation: PhyloP100: 7.91

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 15) in uniprot entity LDLR_HUMAN there are 28 pathogenic changes around while only 2 benign (93%) 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 chr19-11105334-G-T is described in Lovd as [Pathogenic].
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.995
• PP5: Variant 19-11105333-T-C is Pathogenic according to our data. Variant chr19-11105333-T-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 251219.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr19-11105333-T-C is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
LDLR	NM_000527.5	c.427T>C	p.Cys143Arg	missense_variant	4/18	ENST00000558518.6	NP_000518.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
LDLR	ENST00000558518.6	c.427T>C	p.Cys143Arg	missense_variant	4/18	1	NM_000527.5	ENSP00000454071	P3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461608 Hom.: 0 Cov.: 33 AF XY: 0.00000138 AC XY: 1 AN XY: 727136

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: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:7

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hypercholesterolemia, familial, 1 Pathogenic:5

Pathogenic, criteria provided, single submitter	clinical testing	Fulgent Genetics, Fulgent Genetics	Oct 31, 2018	- -
Pathogenic, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Nov 08, 2022	- -
Likely pathogenic, criteria provided, single submitter	literature only	LDLR-LOVD, British Heart Foundation	Mar 25, 2016	- -
Likely pathogenic, criteria provided, single submitter	research	Cardiovascular Research Group, Instituto Nacional de Saude Doutor Ricardo Jorge	Mar 01, 2016	0/190 non-FH alleles -
Likely pathogenic, criteria provided, single submitter	clinical testing	Molecular Genetics Laboratory, Centre for Cardiovascular Surgery and Transplantation	Nov 05, 2016	Disrupt disulfide bridge between Cys128 and Cys143. -

Familial hypercholesterolemia Pathogenic:2

Likely pathogenic, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Mar 12, 2019	This missense variant (also known as p.Cys122Arg in the mature protein) is located in the third LDLR type A repeat of the ligand binding domain of the LDLR protein. Although functional studies have not been performed, this variant changes one of the functionally critical cysteine residues that form intra-repeat disulfide bonds in the ligand binding domain (PMID: 15952897) and is expected to have deleterious impact on the LDLR protein folding and stability. Computational splicing tools suggest that this variant may not impact RNA splicing. This variant has been reported in multiple individuals affected with familial hypercholesterolemia (PMID: 11462246, 20828696, 21310417, 22698793, 24627126). This variant has been reported in three affected individuals from a Portuguese family (PMID: 24627126) and has also been detected in two affected siblings tested at Color (internal data). This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). Based on available evidence, this variant is classified as Likely Pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Jan 11, 2023	This variant is not present in population databases (gnomAD no frequency). This sequence change replaces cysteine, which is neutral and slightly polar, with arginine, which is basic and polar, at codon 143 of the LDLR protein (p.Cys143Arg). This missense change has been observed in individuals with familial hypercholesterolemia (PMID: 11462246, 20828696, 22698793; Invitae). For these reasons, this variant has been classified as Pathogenic. This variant disrupts the p.Cys143 amino acid residue in LDLR. Other variant(s) that disrupt this residue have been observed in individuals with LDLR-related conditions (PMID: 11462246, 30270055, 30592178), which suggests that this may be a clinically significant amino acid residue. 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). 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: 251219). This variant is also known as C122R. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.97
BayesDel_addAF	Pathogenic	0.58	D
BayesDel_noAF	Pathogenic	0.59
CADD	Uncertain	25
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.98	D;.;.;.
Eigen	Pathogenic	0.84
Eigen_PC	Pathogenic	0.67
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Uncertain	0.91	D;D;D;D
M_CAP	Pathogenic	0.79	D
MetaRNN	Pathogenic	1.0	D;D;D;D
MetaSVM	Pathogenic	0.90	D
MutationAssessor	Pathogenic	4.5	H;.;.;H
MutationTaster	Benign	1.0	D;D;D;D;D;D;D
PrimateAI	Uncertain	0.67	T
PROVEAN	Pathogenic	-11	D;D;D;D
REVEL	Pathogenic	0.96
Sift	Pathogenic	0.0	D;D;D;D
Sift4G	Pathogenic	0.0	D;D;D;D
Polyphen		1.0	D;.;.;.
Vest4		0.96
MutPred		0.92		Loss of catalytic residue at V145 (P = 0.0541);Loss of catalytic residue at V145 (P = 0.0541);.;Loss of catalytic residue at V145 (P = 0.0541);
MVP		1.0
MPC		1.1
ClinPred		1.0	D
GERP RS		5.6
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.8
Varity_R		0.96
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: rs875989901; hg19: chr19-11216009;