rs577934998
Variant summary
Our verdict is Likely pathogenic. Variant got 9 ACMG points: 9P and 0B. PM2PM1PM3PS4_SupportingPP4PP3
This summary comes from the ClinGen Evidence Repository: The NM_000527.5(LDLR):c.664T>C (p.Cys222Arg) variant is classified as a Likely pathogenic variant for Familial Hypercholesterolemia by applying evidence codes PM2, PM1, PM3, PS4_supporting, 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: PM2: PopMax MAF = 0.0001098 (0.01%) in East Asian exomes (gnomAD v2.1.1)PM1: Variant meets PM2 and alters Cys222, one of the cysteine residues listed.PM3: Variant meets PM2 and is identified in two index cases with homozygous FH phenotype (LDL mmol/L = 17.9 and 14.09 respectively), PMID:15823276PS4_supporting: Variant meets PM2 and is identified in at least 5 index cases who fulfill SB possible/definite FH or DLCN>=6 criteria for FH from GeneDx Inc., Ambry Genetics, and the Cardiovascular Genetics Laboratory (PathWest Laboratory Medicine WA)PP3 : REVEL = 0.966.PP4: Variant meets PM2 and identified in at least 2 FH case from GeneDx Inc, 1 FH case from Cardiovascular Genetics Laboratory (PathWest Laboratory Medicine WA), and 1 FH case from Ambry Genetics, all of them fulfilling SB criteria for possible/definite FH or DLCN > 6. LINK:https://erepo.genome.network/evrepo/ui/classification/CA044260/MONDO:0007750/013
Frequency
Consequence
NM_000527.5 missense
Scores
Clinical Significance
Conservation
Genome browser will be placed here
ACMG classification
Verdict is Likely_pathogenic. Variant got 9 ACMG points.
Transcripts
RefSeq
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
---|---|---|---|---|---|---|---|---|
LDLR | NM_000527.5 | c.664T>C | p.Cys222Arg | missense_variant | Exon 4 of 18 | ENST00000558518.6 | NP_000518.1 |
Ensembl
Frequencies
GnomAD3 genomes AF: 0.00000658 AC: 1AN: 151930Hom.: 0 Cov.: 33
GnomAD3 exomes AF: 0.00000801 AC: 2AN: 249776Hom.: 0 AF XY: 0.00000738 AC XY: 1AN XY: 135540
GnomAD4 exome AF: 6.86e-7 AC: 1AN: 1458458Hom.: 0 Cov.: 33 AF XY: 0.00000138 AC XY: 1AN XY: 724944
GnomAD4 genome AF: 0.00000658 AC: 1AN: 152046Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0AN XY: 74314
ClinVar
Submissions by phenotype
Hypercholesterolemia, familial, 1 Pathogenic:10Uncertain:1
- -
- -
- -
subject mutated among 2600 FH index cases screened = 1 , family member = 1 /FH-France / Software predictions: Damaging -
The NM_000527.5(LDLR):c.664T>C (p.Cys222Arg) variant is classified as a Likely pathogenic variant for Familial Hypercholesterolemia by applying evidence codes PM2, PM1, PM3, PS4_supporting, 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: PM2: PopMax MAF = 0.0001098 (0.01%) in East Asian exomes (gnomAD v2.1.1) PM1: Variant meets PM2 and alters Cys222, one of the cysteine residues listed. PM3: Variant meets PM2 and is identified in two index cases with homozygous FH phenotype (LDL mmol/L = 17.9 and 14.09 respectively), PMID: 15823276 PS4_supporting: Variant meets PM2 and is identified in at least 5 index cases who fulfill SB possible/definite FH or DLCN>=6 criteria for FH from GeneDx Inc., Ambry Genetics, and the Cardiovascular Genetics Laboratory (PathWest Laboratory Medicine WA) PP3 : REVEL = 0.966. PP4: Variant meets PM2 and identified in at least 2 FH case from GeneDx Inc, 1 FH case from Cardiovascular Genetics Laboratory (PathWest Laboratory Medicine WA), and 1 FH case from Ambry Genetics, all of them fulfilling SB criteria for possible/definite FH or DLCN > 6. -
- -
The patient was admitted to the Interventional Cardiology department, Nhan Dan Gia Dinh hospital, Vietnam and was diagnosed with stable angina CCS III (confirmed by Coronary MSCT), Triple vessel disease, and Hypertension. Furthermore, she had hyperlipidemia with a sign of Arcus Senilis in both eyes. Before that, her older sister was also diagnosed with hyperlipidemia. Her genetic testing showed a heterogeneous variant of LDLR gene, c.664T>C (p.Cys222Arg). This variant affects the p.Cys222 amino acid residue in LDLR. Despite its “Conflicting interpretations of pathogenicity” in ClinVar (only 4 over 10 submissions recorded with pathogenic status), her clinical features strongly suggest the diagnosis of Familial Hypercholesterolemia. This mutation record is expected to contribute to the clinical significance of the variant. The Interventional Cardiology department, Nhan Dan Gia Dinh hospital, Ho Chi Minh City, Vietnam played a main role in diagnosing this case. -
This missense variant replaces cysteine with arginine at codon 222 in the LDLR type A repeat 5 of the LDLR protein. This variant is also known as p.Cys201Arg in the mature 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 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 over 10 individuals affected with familial hypercholesterolemia (PMID: 10532689, 15823276, 15823288, 22883975, 25043216, 30293936, 31345425, 32829317, 33740630, 33994402). This variant has been identified in 2/249776 chromosomes in the general population by the Genome Aggregation Database (gnomAD). Multiple different variants affecting the same codon are considered to be disease-causing (ClinVar variation ID: 183093, 251362, 251365, 251361), suggesting that cysteine at this position is important for LDLR protein function. Based on the available evidence, this variant is classified as Likely Pathogenic. -
- -
- -
- -
not provided Pathogenic:2
The best available variant frequency is uninformative because it is below the disease allele frequency. Statistically enriched in patients compared to ethnically matched controls. Predicted to have a damaging effect on the protein. -
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; Also known as p.(C201R), c.541 T>C; This variant is associated with the following publications: (PMID: 12553167, 15823288, 22883975, 25043216, 34426522, 32041611, 33740630, 34037665, 2988123, 12459547, 15823276, 33994402, 36685950, 38138952) -
Familial hypercholesterolemia Pathogenic:2
This sequence change replaces cysteine, which is neutral and slightly polar, with arginine, which is basic and polar, at codon 222 of the LDLR protein (p.Cys222Arg). This variant is present in population databases (rs577934998, gnomAD 0.01%). This missense change has been observed in individuals with hypercholesterolemia (PMID: 15823276, 22883975, 25043216; internal data). 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 C201R and c.541T>C. ClinVar contains an entry for this variant (Variation ID: 226332). 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 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). This variant disrupts the p.Cys222 amino acid residue in LDLR. Other variant(s) that disrupt this residue have been observed in individuals with LDLR-related conditions (PMID: 7573037, 24671153), which suggests that this may be a clinically significant amino acid residue. For these reasons, this variant has been classified as Pathogenic. -
Variant summary: LDLR c.664T>C (p.Cys222Arg) results in a non-conservative amino acid change in the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 8e-06 in 249776 control chromosomes (gnomAD). c.664T>C has been reported in the literature in multiple individuals affected with Familial Hypercholesterolemia (examples: Hooper_2012, Martn-Campos_2018, and Leren_2021). These data indicate that the variant is very likely to be associated with disease. Other variants located at the same codon have been reported in association with Hypercholesterolaemia (C222G, C222F, C222W, C222Y; HGMD). Eight submitters have provided clinical-significance assessments for this variant to ClinVar after 2014 and classified the variant as pathogenic/likely pathogenic (n=7) and VUS (n=1). Based on the evidence outlined above, the variant was classified as pathogenic. -
Cardiovascular phenotype Pathogenic:1
The p.C222R variant (also known as c.664T>C), located in coding exon 4 of the LDLR gene, results from a T to C substitution at nucleotide position 664. The cysteine at codon 222 is replaced by arginine, an amino acid with highly dissimilar properties. This alteration, also referred to as p.C201R, has been reported in multiple patients with familial hypercholesterolemia (Damgaard D et al. Atherosclerosis. 2005;180:155-60; Sözen MM et al. Atherosclerosis. 2005;180:63-71; Hooper AJ et al. Atherosclerosis. 2012;224:430-4; Zhao X et al. Int J Cardiol. 2014;176:e15-9). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Furthermore, internal structural analysis predicts this alteration to disrupt a cysteine-cysteine bridge in a conserved motif in a region of known function (Fass D et al. Nature. 1997;388(6643):691-3). Alterations at the same amino acid position, p.C222G (Taylor A et al. Clin Genet. 2010;77:572-80), C222F (Fouchier SW et al. Hum Genet. 2001;109:602-15), p.C222W (Medeiros AM et al. Genet Med. 2016;18:316-24) and p.C222Y (Koivisto UM et al. Am J Hum Genet. 1995;57:789-97), have also been reported in individuals with hypercholesterolemia. Based on the majority of available evidence to date, this variant is likely to be pathogenic. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at