rs879255049
Variant summary
Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong
The NM_000527.5(LDLR):c.1845+1G>A variant causes a splice donor, intron change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★).
Frequency
Consequence
NM_000527.5 splice_donor, intron
Scores
Clinical Significance
Conservation
Genome browser will be placed here
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.1845+1G>A | splice_donor_variant, intron_variant | Intron 12 of 17 | ENST00000558518.6 | NP_000518.1 |
Ensembl
Frequencies
GnomAD3 genomes Cov.: 32
GnomAD4 exome Cov.: 34
GnomAD4 genome Cov.: 32
ClinVar
Submissions by phenotype
Hypercholesterolemia, familial, 1 Pathogenic:6
- -
- -
- -
- -
- -
- -
Familial hypercholesterolemia Pathogenic:3
Variant summary: LDLR c.1845+1G>A is located in a canonical splice-site and is predicted to affect mRNA splicing resulting in a significantly altered protein due to either exon skipping, shortening, or inclusion of intronic material. Several computational tools predict a significant impact on normal splicing: Three predict the variant abolishes a 5' splicing donor site. At least one publication reports experimental evidence that this variant affects mRNA splicing (Hobbs_1992). The variant was absent in 251452 control chromosomes (gnomAD). The variant c.1845+1G>A (also known as FH Tunis) has been reported in the literature in multiple homozygous-, compound heterozygous- and heterozygous individuals affected with Familial Hypercholesterolemia, where patients with biallelic variants had a more severe phenotype (e.g. Hobbs_1992, Jelassi_2010, Jelassi_2011, Slimani_2012, Du_2022). These data indicate that the variant is very likely to be associated with disease. Publications also reported experimental evidence evaluating an impact on protein function and demonstrated that this variant resulted in less than 2% LDL receptor activity in fibroblasts derived from homozygous patients (Hobbs_1992, Jelassi_2011). The following publications have been ascertained in the context of this evaluation (PMID: 1301956, 20144596, 21115573, 22417841, 36325061). ClinVar contains an entry for this variant (Variation ID: 252067). Based on the evidence outlined above, the variant was classified as pathogenic. -
This sequence change affects a donor splice site in intron 12 of the LDLR gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in LDLR are known to be pathogenic (PMID: 20809525, 28645073). This variant is not present in population databases (gnomAD no frequency). Disruption of this splice site has been observed in individuals with familial hypercholesterolemia (PMID: 15556094, 21115573). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 252067). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic. -
This variant causes a G to A nucleotide substitution at the + 1 canonical donor position of intron 12 of the LDLR gene. Splice site prediction tools suggest that this variant may have a significant impact on RNA splicing. Although this prediction has not been confirmed in published RNA studies, this variant is expected to result in an absent or disrupted protein product. Functional studies using cultured fibroblasts derived from individuals homozygous for this variant and clinically affected with familial hypercholesterolemia have shown that this variant causes a significant reduction in LDL receptor activity (PMID: 1301956, 21115573). This LDLR variant has been reported in at least seven heterozygous individuals affected with familial hypercholesterolemia (PMID: 1301956, 15556094, 21115573, 21310417, 22417841, 27765764, 28645073). This variant has also been observed in compound heterozygous state with a known pathogenic LDLR variant in one individual affected with severe homozygous familial hypercholesterolemia, a phenotype expected of having two deleterious LDLR variants (PMID: 36325061). It has been shown that this variant segregates with disease in multiple affected individuals across two families (PMID: 21115573). This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). Loss of LDLR function is a known mechanism of disease (clinicalgenome.org). Based on the available evidence, this variant is classified as Pathogenic. -
Cardiovascular phenotype Pathogenic:1
The c.1845+1G>A intronic pathogenic mutation results from a G to A substitution one nucleotide after coding exon 12 of the LDLR gene. This alteration, also known as FH Tunis, has been reported as heterozygous and homozygous in subjects with familial hypercholesterolemia (FH) (Jelassi A et al. Ann Clin Biochem, 2011 Jan;48:83-6; Laurie AD et al. Atheroscler Suppl, 2004 Dec;5:13-5; Dušková L et al. Atherosclerosis, 2011 May;216:139-45; Wang J et al. Arterioscler Thromb Vasc Biol, 2016 12;36:2439-2445). This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). In silico splice site analysis predicts that this alteration will weaken the native splice donor site and may result in the creation or strengthening of a novel splice donor site. In addition to the clinical data presented in the literature, alterations that disrupt the canonical splice site are expected to cause aberrant splicing, resulting in an abnormal protein or a transcript that is subject to nonsense-mediated mRNA decay. As such, this alteration is classified as a disease-causing mutation. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at