rs752191968
Variant summary
Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong
The NM_000527.5(LDLR):c.337dupG(p.Glu113GlyfsTer17) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,198 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.
Frequency
Consequence
NM_000527.5 frameshift
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Pathogenic. Variant got 18 ACMG points.
Transcripts
RefSeq
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
---|---|---|---|---|---|---|---|---|
LDLR | NM_000527.5 | c.337dupG | p.Glu113GlyfsTer17 | frameshift_variant | Exon 4 of 18 | ENST00000558518.6 | NP_000518.1 |
Ensembl
Frequencies
GnomAD3 genomes Cov.: 33
GnomAD3 exomes AF: 0.00000399 AC: 1AN: 250566Hom.: 0 AF XY: 0.00 AC XY: 0AN XY: 135724
GnomAD4 exome AF: 0.00000137 AC: 2AN: 1461198Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0AN XY: 726934
GnomAD4 genome Cov.: 33
ClinVar
Submissions by phenotype
Hypercholesterolemia Pathogenic:1
The p.E113fs variant segregates with elevated level of LDL-C in a family of 5 individuals. The allele frequency of this variant in the population is 0.00001 as reported by the ExAC database. -
Hypercholesterolemia, familial, 1 Pathogenic:1
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not provided Pathogenic:1
p.Glu113Glyfs*17 (c.337dupG; also known as 338insG) in exon 4 of the LDLR gene (NM_000527.4) Given that this is a loss-of-function variant in a gene in which truncation is a known mechanism of disease, moderate case data and its rarity in the general population, we consider this variant disease-causing and we do feel it is suitable for assessing risk in healthy relatives ("predictive genetic testing"). This variant causes a shift in the reading frame of the LDLR gene, producing a truncated protein. Loss-of-function (truncated proteins) variants are a known mechanism of LDLR-associated familial hypercholesterolemia. The variant has been seen in at least 4 unrelated cases of familial hypercholesterolemia (not including this patient's family). There is moderate case data. This variant was present in 4 of 46 unrelated patients with familial hypercholesterolemia (Robles-Osorio et al, 2006), and was a "common" variant identified amongst 123 unrelated Mexican patients (per an abstract by Vazques Cardenas et al, 2015). This variant is not present in ClinVar; however another truncating variant at this codon (c.337G>T; p.Glu113Ter) is classified as pathogenic by four laboratories. The variant was reported online in 1 of 122,762 individuals in the Genome Aggregation Consortium Dataset (gnomAD; http://gnomad.broadinstitute.org/), which currently includes variant calls on >140,000 unrelated individuals of African, Asian, European, Ashkenazi, Latino descent. Specifically, the variant was observed in 1 of 16,789 individuals of Latino descent (MAF=0.003%). The phenotype of those individuals is not publicly available. The dataset is comprised of multiple cohorts, some of which were recruited from the general population, others were enriched for common cardiovascular disease. Note that other variants with strong evidence for pathogenicity have been seen at similar frequencies in datasets like this so this does not necessarily rule out pathogenicity (Pan et al 2012). -
Cardiovascular phenotype Pathogenic:1
The c.337dupG pathogenic mutation, located in coding exon 4 of the LDLR gene, results from a duplication of G at nucleotide position 337, causing a translational frameshift with a predicted alternate stop codon (p.E113Gfs*17). This alteration (referred to as 338insG) has been detected in a cohort of individuals reported to have familial hypercholesterolemia (Robles-Osorio L et al. Arch. Med. Res., 2006 Jan;37:102-8). This alteration was also detected in a Mexican family with familial hypercholesterolemia. In this family, two homozygous children were reported, and both had higher LDL-C and total cholesterol levels than their heterozygous parents and sibling (Wong KHY et al. Mol Genet Genomic Med, 2019 12;7:e1007). In addition to the clinical data presented in the literature, this alteration is expected to result in loss of function by premature protein truncation or nonsense-mediated mRNA decay. As such, this alteration is interpreted as a disease-causing mutation. -
Familial hypercholesterolemia Pathogenic:1
This sequence change creates a premature translational stop signal (p.Glu113Glyfs*17) in the LDLR gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in LDLR are known to be pathogenic (PMID: 20809525, 28645073). This variant is present in population databases (rs752191968, gnomAD 0.003%). This premature translational stop signal has been observed in individuals with familial hypercholesterolemia (PMID: 16314194). 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 338insG. ClinVar contains an entry for this variant (Variation ID: 440560). 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