rs875989890

Positions:

• chr19-11102697-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 ENST00000558518.6(LDLR):​c.224G>A​(p.Cys75Tyr) 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 Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. C75S) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 31)
• Consequence: LDLR ENST00000558518.6 missense
• Clinical Significance: Likely pathogenic criteria provided, multiple submitters, no conflicts P:5
• Conservation: PhyloP100: 9.85

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 hotspot region, there are 5 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 11 uncertain in ENST00000558518.6
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr19-11102696-T-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 251079.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.993
• PP5: Variant 19-11102697-G-A is Pathogenic according to our data. Variant chr19-11102697-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 226308.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr19-11102697-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.224G>A	p.Cys75Tyr	missense_variant	3/18	ENST00000558518.6	NP_000518.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
LDLR	ENST00000558518.6	c.224G>A	p.Cys75Tyr	missense_variant	3/18	1	NM_000527.5	ENSP00000454071	P3

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 31

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:5

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hypercholesterolemia, familial, 1 Pathogenic:4

Likely pathogenic, criteria provided, single submitter	clinical testing	MGZ Medical Genetics Center	Aug 19, 2021	- -
Likely pathogenic, criteria provided, single submitter	literature only	LDLR-LOVD, British Heart Foundation	Mar 25, 2016	- -
Pathogenic, no assertion criteria provided	clinical testing	Cardiovascular Genetics Laboratory, PathWest Laboratory Medicine WA - Fiona Stanley Hospital	Jun 21, 2013	- -
Pathogenic, no assertion criteria provided	research	Laboratorium voor Moleculaire Diagnostiek Experimentele Vasculaire Geneeskunde, Academisch Medisch Centrum	-	- -

Cardiovascular phenotype Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Sep 22, 2022

The p.C75Y variant (also known as c.224G>A), located in coding exon 3 of the LDLR gene, results from a G to A substitution at nucleotide position 224. The cysteine at codon 75 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 alteration, which is also known as p.C54Y, has been reported in FH cohorts (Geisel J et al. Clin Chem Lab Med, 1998 May;36:279-82; Wang H et al. J Atheroscler Thromb, 2020 Dec;27:1288-1298). Internal structural analysis indicates this variant eliminates a disulfide bond critical for the structural integrity of the LDLR class A repeat 2 domain (Ambry internal data). Another alteration at the same codon, p.C75S (c.223T>A), has been described in a proband with a LDL-C level of 298mg/dL, in a Slovenian pediatric hypercholesterolemia cohort, and in additional probands referred for FH genetic testing (Emi M et al. Jpn Heart J. 1998;39(6):785-789; Klanar G et al. J. Am. Coll. Cardiol. 2015;66(11):1250-1257; Invitae pers.comm.). This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.59	D
BayesDel_noAF	Pathogenic	0.61
CADD	Pathogenic	31
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.98	D;.;.;.;.
Eigen	Pathogenic	1.2
Eigen_PC	Pathogenic	1.0
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.91	D;D;D;D;D
M_CAP	Pathogenic	0.88	D
MetaRNN	Pathogenic	0.99	D;D;D;D;D
MetaSVM	Pathogenic	0.92	D
MutationAssessor	Pathogenic	4.7	H;.;H;H;H
MutationTaster	Benign	1.0	D;D;D;D;D;D;D
PrimateAI	Uncertain	0.60	T
PROVEAN	Pathogenic	-10	D;D;D;D;D
REVEL	Pathogenic	0.97
Sift	Pathogenic	0.0	D;D;D;D;D
Sift4G	Pathogenic	0.0	D;D;D;D;D
Polyphen		1.0	D;.;.;.;.
Vest4		0.98
MutPred		0.92		Loss of disorder (P = 0.0478);Loss of disorder (P = 0.0478);Loss of disorder (P = 0.0478);Loss of disorder (P = 0.0478);Loss of disorder (P = 0.0478);
MVP		1.0
MPC		1.1
ClinPred		1.0	D
GERP RS		5.7
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
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: rs875989890; hg19: chr19-11213373;