19-11102741-G-T

Variant names:

• chr19-11102741-G-T
• rs749038326
• NM_000527.5:c.268G>T

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM2 PP3 PP4 PM5_Strong

This summary comes from the ClinGen Evidence Repository: The NM_000527.5(LDLR):c.268G>T (p.Asp90Tyr) variant is classified as Likely pathogenic for Familial Hypercholesterolemia by applying evidence codes (PM5_Strong, PM2, PP3 and PP4) as defined by the ClinGen Familial Hypercholesterolemia Expert Panel LDLR-specific variant curation guidelines (https://doi.org/10.1101/2021.03.17.21252755).The supporting evidence is as follows: PM5_Strong - Four more missense variants described in same codon: --- 3 variants classified as Pathogenic, so PM5_Strong is Met.PM2 - No population data was found for this variant in gnomAD (gnomAD v2.1.1).PM5 - Four more missense variants described in same codon, 3 variants classified as Pathogenic, so PM5 is Met.PP3 - REVEL = 0.958. It is above 0.75, so PP3 is Met.PP4 - Variant meets PM2. Identified in 1 index case who fulfills Simon-Broome criteria from Center of molecular biology and gene therapy. LINK:https://erepo.genome.network/evrepo/ui/classification/CA10584820/MONDO:0007750/013

• Frequency: Genomes: not found (cov: 31)
• Consequence: LDLR NM_000527.5 missense
• Clinical Significance: Likely pathogenic reviewed by expert panel P:7
• Conservation: PhyloP100: 9.95

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.

• PM2: For more information check the summary or visit ClinGen Evidence Repository.
• PM5: For more information check the summary or visit ClinGen Evidence Repository.
• PP3: For more information check the summary or visit ClinGen Evidence Repository.
• PP4: For more information check the summary or visit ClinGen Evidence Repository.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
LDLR	NM_000527.5	c.268G>T	p.Asp90Tyr	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.268G>T	p.Asp90Tyr	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: Likely pathogenic

Submissions summary: Pathogenic:7

Revision: reviewed by expert panel

Submissions by phenotype

Hypercholesterolemia, familial, 1 Pathogenic:5

Jun 08, 2023

All of Us Research Program, National Institutes of Health

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This missense variant (also known as p.Asp69Tyr in the mature protein) replaces aspartic acid with tyrosine at codon 90 in the second LDLR type A of the ligand binding domain of the LDLR protein. Computational prediction suggests that this variant may have a 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 been reported in an individual affected with familial hypercholesterolemia (PMID: 34456200). This variant has also been reported in compound heterozygous state in individuals affected with homozygous familial hypercholesterolemia (PMID: 8347689). This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). Different variants occurring at the same codon (p.Asp90Asn, p.Asp90Gly, p.Asp90Glu, p.Asp90Ala), are well documented pathogenic mutations (ClinVar variation IDs: 215505, 226313, 251107, 440555), indicating that aspartic acid at this position is important for LDLR protein function. Based on the available evidence, this variant is classified as Likely Pathogenic. -

Nov 05, 2016

Molecular Genetics Laboratory, Centre for Cardiovascular Surgery and Transplantation

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Jun 07, 2021

ClinGen Familial Hypercholesterolemia Variant Curation Expert Panel

Significance: Likely pathogenic

Review Status: reviewed by expert panel

Collection Method: curation

The NM_000527.5(LDLR):c.268G>T (p.Asp90Tyr) variant is classified as Likely pathogenic for Familial Hypercholesterolemia by applying evidence codes (PM5_Strong, PM2, PP3 and PP4) as defined by the ClinGen Familial Hypercholesterolemia Expert Panel LDLR-specific variant curation guidelines (https://doi.org/10.1101/2021.03.17.21252755). The supporting evidence is as follows: PM5_Strong - Four more missense variants described in same codon: --- 3 variants classified as Pathogenic, so PM5_Strong is Met. PM2 - No population data was found for this variant in gnomAD (gnomAD v2.1.1). PM5 - Four more missense variants described in same codon, 3 variants classified as Pathogenic, so PM5 is Met. PP3 - REVEL = 0.958. It is above 0.75, so PP3 is Met. PP4 - Variant meets PM2. Identified in 1 index case who fulfills Simon-Broome criteria from Center of molecular biology and gene therapy. -

Jul 22, 2023

Neuberg Centre For Genomic Medicine, NCGM

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The missense c.268G>T p.Asp90Tyr variant in the LDLR gene has been observed in individuals with familial hypercholesterolemia Rubinsztein, D C et al., 1993. Other variants that disrupt this residue have been determined to be pathogenic Han, Soo Min et al., 2015. The variant is absent in gnomAD Exomes. It is submitted to ClinVar as Likely Pathogenic reviewed by expert panel. The amino acid Aspartic acid at position 90 is changed to a Tyrosine changing protein sequence and it might alter its composition and physico-chemical properties. Multiple lines of computational evidence Polyphen - Damaging, SIFT – Damaging and MutationTaster - Disease causing predict a damaging effect on protein structure and function for this variant. The amino acid Aspartic acid in LDLR is predicted as conserved by GERP++ and PhyloP across 100 vertebrates. For these reasons, this variant has been classified as Likely Pathogenic. -

Mar 25, 2016

LDLR-LOVD, British Heart Foundation

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: literature only

- -

Cardiovascular phenotype Pathogenic:1

Jul 22, 2024

Ambry Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.D90Y pathogenic mutation (also known as c.268G>T), located in coding exon 3 of the LDLR gene, results from a G to T substitution at nucleotide position 268. The aspartic acid at codon 90 is replaced by tyrosine, an amino acid with highly dissimilar properties. This alteration, which is also known as p.D69Y, has been reported in individuals with concerns for familial hypercholesterolemia (FH), including being identified in trans with another alteration in LDLR in an individual with homozygous FH (Rubinsztein DC et al. Biochim Biophys Acta, 1993 Aug;1182:75-82; Kim H et al. J Atheroscler Thromb, 2022 Aug;29:1176-1187; Ambry internal data). Another variant at the same codon, p.D90N (c.268G>A), has been detected in multiple individuals with FH and in FH cohorts from a variety of ethnic backgrounds (Day IN et al. Hum. Mutat., 1997;10:116-27; Mak YT et al. Arterioscler. Thromb. Vasc. Biol., 1998 Oct;18:1600-5; Khoo KL et al. Clin. Genet., 2000 Aug;58:98-105; Chang JH et al. J. Lipid Res., 2003 Oct;44:1850-8; Fouchier SW et al. Hum. Mutat., 2005 Dec;26:550-6; Norsworthy PJ et al. BMC Med. Genet., 2014 Jun;15:70). This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the supporting evidence, this variant is interpreted as a disease-causing mutation. -

Familial hypercholesterolemia Pathogenic:1

Mar 21, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces aspartic acid, which is acidic and polar, with tyrosine, which is neutral and polar, at codon 90 of the LDLR protein (p.Asp90Tyr). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with familial hypercholesterolemia (PMID: 8347689). This variant is also known as FH Durban-1 and asp69tyr. ClinVar contains an entry for this variant (Variation ID: 251106). 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 disrupts the p.Asp90 amino acid residue in LDLR. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 12837857, 16343504, 21376320, 25962062). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely 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	Pathogenic	28
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.98	D;.;.;.;.
Eigen	Pathogenic	0.92
Eigen_PC	Pathogenic	0.74
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.99	D;D;D;D;D
M_CAP	Pathogenic	0.88	D
MetaRNN	Pathogenic	1.0	D;D;D;D;D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	4.6	H;.;H;H;H
PrimateAI	Benign	0.48	T
PROVEAN	Pathogenic	-8.2	D;D;D;D;D
REVEL	Pathogenic	0.96
Sift	Pathogenic	0.0	D;D;D;D;D
Sift4G	Pathogenic	0.0010	D;D;D;D;D
Polyphen		1.0	D;.;.;.;.
Vest4		0.93
MutPred		0.92		Loss of disorder (P = 0.0236);Loss of disorder (P = 0.0236);Loss of disorder (P = 0.0236);Loss of disorder (P = 0.0236);Loss of disorder (P = 0.0236);
MVP		0.98
MPC		0.90
ClinPred		1.0	D
GERP RS		5.7
RBP_binding_hub_radar		0.97
RBP_regulation_power_radar		2.7
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: rs749038326; hg19: chr19-11213417;