chr19-11105553-G-A

Position:

• chr19-11105553-G-A

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.647G>A​(p.Cys216Tyr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,460,952 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. C216F) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: LDLR NM_000527.5 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:6
• Conservation: PhyloP100: 9.88

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 56 pathogenic changes around while only 2 benign (97%) 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 chr19-11105553-G-T is described in Lovd as [Likely_pathogenic].
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.997
• PP5: Variant 19-11105553-G-A is Pathogenic according to our data. Variant chr19-11105553-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 251346.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr19-11105553-G-A is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
LDLR	NM_000527.5	c.647G>A	p.Cys216Tyr	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.647G>A	p.Cys216Tyr	missense_variant	4/18	1	NM_000527.5	ENSP00000454071.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1460952 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 726692

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: 0.00

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:6

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hypercholesterolemia, familial, 1 Pathogenic:4

Likely pathogenic, 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	- -
Pathogenic, no assertion criteria provided	research	Rajaie Cardiovascular, Medical and Research Center, Iran University of Medical Sciences	-	- -
Likely pathogenic, criteria provided, single submitter	clinical testing	Centre de Génétique Moléculaire et Chromosomique, Unité de génétique de l'Obésité et des Dyslipidémies, APHP, GH Hôpitaux Universitaires Pitié-Salpêtrière / Charles-Foix	Dec 16, 2016	subject mutated among 2600 FH index cases screened = 1 , family member = 6 / Software predictions: Damaging -

Cardiovascular phenotype Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Oct 15, 2018

The p.C216Y variant (also known as c.647G>A), located in coding exon 4 of the LDLR gene, results from a G to A substitution at nucleotide position 647. The cysteine at codon 216, located in LDLR class A repeat 5, is replaced by tyrosine, 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 a proband with hypercholesterolemia, and in the proband's reportedly affected child (Dedoussis GV et al. Hum Mutat. 2004;23:285-6). Internal structural analysis indicates this alteration eliminates a disulfide bond critical for the structural integrity of the LDLR class A repeat 5 (Ambry internal data). Another alteration affecting this codon (p.C216R, c.646T>C) has also been reported in an FH cohort (Mozas P et al. Hum Mutat. 2004;24:187). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the majority of available evidence to date, this variant is likely to be pathogenic. -

Familial hypercholesterolemia Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Dec 01, 2023

This sequence change replaces cysteine, which is neutral and slightly polar, with tyrosine, which is neutral and polar, at codon 216 of the LDLR protein (p.Cys216Tyr). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individuals with hypercholesterolemia (PMID: 14974088, 33732287; Invitae). ClinVar contains an entry for this variant (Variation ID: 251346). 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 with a positive predictive value of 95%. 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.Cys216 amino acid residue in LDLR. Other variant(s) that disrupt this residue have been observed in individuals with LDLR-related conditions (PMID: 15241806, 18096825), which suggests that this may be a clinically significant amino acid residue. For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.58	D
BayesDel_noAF	Pathogenic	0.60
CADD	Uncertain	26
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.97	D;.;.;.
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.88
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Pathogenic	1.0	D;D;D;D
M_CAP	Pathogenic	0.93	D
MetaRNN	Pathogenic	1.0	D;D;D;D
MetaSVM	Pathogenic	0.91	D
MutationAssessor	Pathogenic	4.9	H;.;.;H
PrimateAI	Uncertain	0.65	T
PROVEAN	Pathogenic	-10	D;D;D;D
REVEL	Pathogenic	0.93
Sift	Pathogenic	0.0	D;D;D;D
Sift4G	Pathogenic	0.0	D;D;D;D
Polyphen		1.0	D;.;.;.
Vest4		0.98
MutPred		0.94		Gain of relative solvent accessibility (P = 0.0522);Gain of relative solvent accessibility (P = 0.0522);.;Gain of relative solvent accessibility (P = 0.0522);
MVP		1.0
MPC		1.1
ClinPred		1.0	D
GERP RS		5.6
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.99
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: rs879254611; hg19: chr19-11216229;