rs775092314

Variant names:

• chr19-11120411-T-C
• rs775092314
• NM_000527.5:c.2029T>C

Variant summary

Our verdict is Pathogenic. The variant received 17 ACMG points: 17P and 0B. PM1 PM5 PP2 PP3_Strong PP5_Very_Strong

The NM_000527.5(LDLR):​c.2029T>C​(p.Cys677Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000372 in 1,614,082 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. C677Y) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000034 (0 hom.)
• Consequence: LDLR NM_000527.5 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:9
• Conservation: PhyloP100: 8.00
• Publications: 6 publications found

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]

LDLR Gene-Disease associations (from GenCC):

• hypercholesterolemia, familial, 1

  Inheritance: AD, SD Classification: DEFINITIVE, STRONG Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae), Laboratory for Molecular Medicine, ClinGen
• homozygous familial hypercholesterolemia

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Pathogenic. The variant received 17 ACMG points.

• PM1: In a hotspot region, there are 20 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 10 uncertain in NM_000527.5
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr19-11120412-G-A is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 252178.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 678 curated pathogenic missense variants (we use a threshold of 10). The gene has 92 curated benign missense variants. Gene score misZ: 0.12407 (below the threshold of 3.09). Trascript score misZ: 0.59338 (below the threshold of 3.09). GenCC associations: The gene is linked to hypercholesterolemia, familial, 1, homozygous familial hypercholesterolemia.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.996
• PP5: Variant 19-11120411-T-C is Pathogenic according to our data. Variant chr19-11120411-T-C is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 226384.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
LDLR	NM_000527.5	c.2029T>C	p.Cys677Arg	missense_variant	Exon 14 of 18	ENST00000558518.6	NP_000518.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
LDLR	ENST00000558518.6	c.2029T>C	p.Cys677Arg	missense_variant	Exon 14 of 18	1	NM_000527.5	ENSP00000454071.1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152234 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.00000398 AC: 1 AN: 251194 AF XY: 0.00

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000880

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000342 AC: 5 AN: 1461848 Hom.: 0 Cov.: 35 AF XY: 0.00 AC XY: 0 AN XY: 727230

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53374

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00000360 AC: 4 AN: 1112012

Other (OTH) AF: 0.0000166 AC: 1 AN: 60396

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152234 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74376

African (AFR) AF: 0.00 AC: 0 AN: 41466

American (AMR) AF: 0.00 AC: 0 AN: 15274

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5202

South Asian (SAS) AF: 0.00 AC: 0 AN: 4832

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10630

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 68038

Other (OTH) AF: 0.00 AC: 0 AN: 2092

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:9

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hypercholesterolemia, familial, 1 Pathogenic:4

Jun 05, 2008

Cardiovascular Genetics Laboratory, PathWest Laboratory Medicine WA - Fiona Stanley Hospital

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

-

Robarts Research Institute, Western University

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Apr 13, 2018

Human Genome Sequencing Center Clinical Lab, Baylor College of Medicine

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This c.2029T>C (p.Cys677Arg) variant in the LDLR gene has been reported in multiple individuals with familial hypercholesterolemia (PMID: 1301956, 10208479, 10559517) or myocardial infarction (PMID 25487149). Functional studies have indicated that the p.Cys677Arg variant in the LDLR protein has 5-15% receptor activity compared to wild-type LDLR protein (PMID: 1301956). The c.2029T>C variant is rare in the general population and cysteine at position 677 of the LDLR protein is highly evolutionarily conserved. The c.2029T>C (p.Cys677Arg) variant in the LDLR gene is 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

- -

not provided Pathogenic:2

Aug 17, 2021

AiLife Diagnostics, AiLife Diagnostics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Feb 18, 2022

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Also known as FH New York-1 and p.C656R; Located within the LDL-receptor EGF precursor domain 3, and participates in disulfide bonding with another cysteine residue which is critical for correct protein structure (Sudhof et al., 1985; Rudenko et al., 2002); Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 10559517, 25487149, 1301956, 16389549, 17142622, 22883975, 27680772, 27765764, 31447099, 32041611, 34037665, 33087929, 2988123, 12459547, 10208479, 19487412) -

Homozygous familial hypercholesterolemia Pathogenic:1

Oct 11, 2019

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.Cys677Arg variant in LDLR has been reported in at least 7 individuals with hypercholesterolemia and segregated with disease in 6 affected individuals from 1 family (Hobbs 1992, Heath 1999, Humphries 2006, Bima 2009, Hooper 2012, Martin 2016, Wang 2016). It has also been identified in 1/113610 of European chromosomes by gnomAD (http://gnomad.broadinstitute.org) and has been reported in ClinVar (Variation ID 226384). An in vitro functional study and computational prediction tools support an impact on protein function (Hobbs 1992). In summary, although additional studies are required to fully establish its clinical significance, this variant meets criteria to be classified as likely pathogenic for autosomal dominant familial . ACMG/AMP Criteria applied: PM2, PS4_Moderate, PP1_Moderate, PP3, PS3_Supporting. -

Cardiovascular phenotype Pathogenic:1

Dec 15, 2021

Ambry Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.C677R pathogenic mutation (also known as c.2029T>C), located in coding exon 14 of the LDLR gene, results from a T to C substitution at nucleotide position 2029. The cysteine at codon 677 is replaced by arginine, an amino acid with highly dissimilar properties. This alteration was detected in conjunction with another alteration in the LDLR gene in an individual whose protein activity was 5-15% of normal (Hobbs HH et al. Hum Mutat. 1992;1(6):445-66). Subsequent studies observed this alteration in several individuals diagnosed with familial hypercholesterolemia (FH) (Humphries SE et al. J Mol Med. 2006; 84(3):203-14; Tosi I et al. Atherosclerosis. 2007;194(1):102-11). In a case report, this alteration was described to co-segregate with FH in multiple individuals in one family (Bima AI et al. Ann Clin Biochem. 2009;46(Pt 5):420-2). Another alteration affecting the same codon (p.C677Y c.2030G>A) has also been described in patients with FH (Salazar LA et al. Hum Mutat. 2002;19(4):462-3). Based on the supporting evidence, p.C677R is interpreted as a disease-causing mutation. -

Familial hypercholesterolemia Pathogenic:1

Dec 10, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces cysteine, which is neutral and slightly polar, with arginine, which is basic and polar, at codon 677 of the LDLR protein (p.Cys677Arg). This variant is present in population databases (rs775092314, gnomAD 0.0009%). This missense change has been observed in individuals with hypercholesterolemia (PMID: 1301956, 10208479, 17142622, 19487412, 22883975, 27680772, 27765764). It has also been observed to segregate with disease in related individuals. Invitae Evidence Modeling of clinical and family history, age, sex, and reported ancestry of multiple individuals with this LDLR variant has been performed. This variant is expected to be pathogenic with a positive predictive value of at least 99%. This is a validated machine learning model that incorporates the clinical features of 363,995 individuals referred to our laboratory for LDLR testing. This variant is also known as p.Cys656Arg. ClinVar contains an entry for this variant (Variation ID: 226384). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt LDLR protein function with a positive predictive value of 95%. This variant disrupts the p.Cys677 amino acid residue in LDLR. Other variant(s) that disrupt this residue have been observed in individuals with LDLR-related conditions (PMID: 9763532, 16389549, 28235710), 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	1.0
BayesDel_addAF	Pathogenic	0.58	D
BayesDel_noAF	Pathogenic	0.60
CADD	Pathogenic	27
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.98	D;.;.;.;.
Eigen	Pathogenic	0.89
Eigen_PC	Pathogenic	0.72
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.99	D;D;D;D;D
M_CAP	Pathogenic	0.96	D
MetaRNN	Pathogenic	1.0	D;D;D;D;D
MetaSVM	Pathogenic	0.90	D
MutationAssessor	Pathogenic	4.8	H;.;.;.;H
PhyloP100		8.0
PrimateAI	Uncertain	0.54	T
PROVEAN	Pathogenic	-11	D;D;D;D;D
REVEL	Pathogenic	0.96
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		0.96		Gain of disorder (P = 0.1056);Gain of disorder (P = 0.1056);.;.;Gain of disorder (P = 0.1056);
MVP		1.0
MPC		1.1
ClinPred		1.0	D
GERP RS		5.3
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		1.0
gMVP		1.0
Mutation Taster		=0/100	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs775092314; hg19: chr19-11231087;