19-11120411-T-C
Variant summary
Our verdict is Pathogenic. The variant received 17 ACMG points: 17P and 0B. PM1PM5PP2PP3_StrongPP5_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
Consequence
NM_000527.5 missense
Scores
Clinical Significance
Conservation
Publications
- hypercholesterolemia, familial, 1Inheritance: AD, SD Classification: DEFINITIVE, STRONG Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae), Laboratory for Molecular Medicine, ClinGen
- homozygous familial hypercholesterolemiaInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
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ACMG classification
Our verdict: Pathogenic. The variant received 17 ACMG points.
Variant Effect in Transcripts
ACMG analysis was done for transcript: NM_000527.5. You can select a different transcript below to see updated ACMG assignments.
RefSeq Transcripts
| Selected | Gene | Transcript | Tags | HGVSc | HGVSp | Effect | Exon Rank | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|---|
| LDLR | NM_000527.5 | MANE Select | c.2029T>C | p.Cys677Arg | missense | Exon 14 of 18 | NP_000518.1 | ||
| LDLR | NM_001195798.2 | c.2029T>C | p.Cys677Arg | missense | Exon 14 of 18 | NP_001182727.1 | |||
| LDLR | NM_001195799.2 | c.1906T>C | p.Cys636Arg | missense | Exon 13 of 17 | NP_001182728.1 |
Ensembl Transcripts
| Selected | Gene | Transcript | Tags | HGVSc | HGVSp | Effect | Exon Rank | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|---|
| LDLR | ENST00000558518.6 | TSL:1 MANE Select | c.2029T>C | p.Cys677Arg | missense | Exon 14 of 18 | ENSP00000454071.1 | ||
| LDLR | ENST00000252444.10 | TSL:1 | c.2287T>C | p.Cys763Arg | missense | Exon 14 of 18 | ENSP00000252444.6 | ||
| LDLR | ENST00000558013.5 | TSL:1 | c.2029T>C | p.Cys677Arg | missense | Exon 14 of 18 | ENSP00000453346.1 |
Frequencies
GnomAD3 genomes AF: 0.00000657 AC: 1AN: 152234Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.00000398 AC: 1AN: 251194 AF XY: 0.00 show subpopulations
GnomAD4 exome AF: 0.00000342 AC: 5AN: 1461848Hom.: 0 Cov.: 35 AF XY: 0.00 AC XY: 0AN XY: 727230 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.00000657 AC: 1AN: 152234Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0AN XY: 74376 show subpopulations
ClinVar
Submissions by phenotype
Hypercholesterolemia, familial, 1 Pathogenic:4
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.
not provided Pathogenic:2
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
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
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. 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). Internal structural analysis indicates this variant eliminates a disulfide bond critical for the structural integrity of the EGF-like 3 domain (Ambry internal data). This variant was identified in one or more individuals with features consistent with familial hypercholesterolemia and segregated with disease in at least one family (Hobbs HH et al. Hum Mutat. 1992;1(6):445-66; Humphries SE et al. J Mol Med. 2006; 84(3):203-14; Tosi I et al. Atherosclerosis. 2007;194(1):102-11; Bima AI et al. Ann Clin Biochem. 2009;46(Pt 5):420-2). Other variant(s) at the same codon, p.C677Y (c.2030G>A), have been identified in individual(s) with features consistent with FH (Salazar LA et al. Hum Mutat. 2002;19(4):462-3). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). Based on the supporting evidence, this variant is interpreted as a disease-causing mutation.
Familial hypercholesterolemia Pathogenic:1
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:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at