19-11102675-T-G

Variant names:

• chr19-11102675-T-G
• rs1057519652
• NM_000527.5:c.202T>G

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM1 PM2 PP3_Strong

The NM_000527.5(LDLR):​c.202T>G​(p.Cys68Gly) 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 Uncertain significance (★★).

• Frequency: Genomes: not found (cov: 31)
• Consequence: LDLR NM_000527.5 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 7.57

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 Likely_pathogenic. Variant got 8 ACMG points.

• PM1: In a disulfide_bond (size 14) in uniprot entity LDLR_HUMAN there are 12 pathogenic changes around while only 1 benign (92%) in NM_000527.5
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.987

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
LDLR	NM_000527.5	c.202T>G	p.Cys68Gly	missense_variant	Exon 3 of 18	ENST00000558518.6	NP_000518.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
LDLR	ENST00000558518.6	c.202T>G	p.Cys68Gly	missense_variant	Exon 3 of 18	1	NM_000527.5	ENSP00000454071.1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 31

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Familial hypercholesterolemia Uncertain:2

Dec 28, 2019

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces cysteine with glycine at codon 68 of the LDLR protein (p.Cys68Gly). The cysteine residue is highly conserved and there is a large physicochemical difference between cysteine and glycine. This variant is not present in population databases (ExAC no frequency). 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). In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). This variant has not been reported in the literature in individuals with LDLR-related conditions. -

Dec 05, 2022

Color Diagnostics, LLC DBA Color Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This missense variant (also known as p.Cys47Gly in the mature protein) replaces cysteine with glycine at codon 68 of the LDLR protein. This variant alters a conserved cysteine residue that is critical for proper protein folding and function (PMID: 2088165, 6091915, 15952897). Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with LDLR-related disorders in the literature. This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -

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	Pathogenic	27
DANN	Uncertain	0.98
DEOGEN2	Pathogenic	0.97	D;.;.;.;.
Eigen	Pathogenic	0.97
Eigen_PC	Pathogenic	0.83
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Benign	0.82	T;T;T;T;T
M_CAP	Pathogenic	0.97	D
MetaRNN	Pathogenic	0.99	D;D;D;D;D
MetaSVM	Pathogenic	0.94	D
MutationAssessor	Pathogenic	4.3	H;.;H;H;H
PrimateAI	Uncertain	0.57	T
PROVEAN	Pathogenic	-11	D;D;D;D;D
REVEL	Pathogenic	0.97
Sift	Pathogenic	0.0	D;D;D;D;D
Sift4G	Uncertain	0.0050	D;D;D;D;D
Polyphen		1.0	D;.;.;.;.
Vest4		0.92
MutPred		0.79		Loss of stability (P = 0.0036);Loss of stability (P = 0.0036);Loss of stability (P = 0.0036);Loss of stability (P = 0.0036);Loss of stability (P = 0.0036);
MVP		1.0
MPC		0.91
ClinPred		1.0	D
GERP RS		5.6
Varity_R		1.0
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: rs1057519652; hg19: chr19-11213351;