19-11102705-CG-C

Position:

• chr19-11102705-CG-C

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_000527.5(LDLR):​c.233delG​(p.Arg78fs) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Likely pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 31)
• Consequence: LDLR NM_000527.5 frameshift
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:6
• Conservation: PhyloP100: 1.51

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 (HGNC:):

ACMG classification

Verdict is Pathogenic. Variant got 18 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 19-11102705-CG-C is Pathogenic according to our data. Variant chr19-11102705-CG-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 369866.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
LDLR	NM_000527.5	c.233delG	p.Arg78fs	frameshift_variant	3/18	ENST00000558518.6	NP_000518.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
LDLR	ENST00000558518.6	c.233delG	p.Arg78fs	frameshift_variant	3/18	1	NM_000527.5	ENSP00000454071.1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 31

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:6

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hypercholesterolemia, familial, 1 Pathogenic:2

Likely pathogenic, criteria provided, single submitter	clinical testing	Robarts Research Institute, Western University	-	- -
Pathogenic, criteria provided, single submitter	clinical testing	Laboratory of molecular diagnosis of dyslipidemias, Università egli studi di Napoli Federico II	May 24, 2021	- -

Familial hypercholesterolemia Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Jul 30, 2024	Variant summary: LDLR c.233delG (p.Arg78LeufsX128) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. The variant was absent in 251492 control chromosomes. c.233delG has been reported in the literature in at-least one individual affected with Familial Hypercholesterolemia (example: Wang_2016). The following publication has been ascertained in the context of this evaluation (PMID: 27765764). ClinVar contains an entry for this variant (Variation ID: 369866). Based on the evidence outlined above, the variant was classified as pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Mar 13, 2022	For these reasons, this variant has been classified as Pathogenic. ClinVar contains an entry for this variant (Variation ID: 369866). This variant has not been reported in the literature in individuals affected with LDLR-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change creates a premature translational stop signal (p.Arg78Leufs*128) 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). -

Homozygous familial hypercholesterolemia Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Jun 14, 2016

This p.Arg78Leufs variant in LDLR has not been previously reported in individuals with familial hypercholesterolemia or in large population studies. This variant is predicted to cause a frameshift, which alters the protein's amino acid sequence beginning at position 78 and leads to a premature termination codon 128 amino acids downstream. This alteration is then predicted to lead to a truncated or absent protein. Heterozygous loss of LDLR function is an established disease mechanism in familial hypercholesterolemia. In summary, this variant meets our criteria to be classified as pathogenic for familial hypercholesterolemia based on predicted impact to the protein and absence from the general population. -

Cardiovascular phenotype Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Mar 25, 2024

The c.233delG pathogenic mutation, located in coding exon 3 of the LDLR gene, results from a deletion of one nucleotide at nucleotide position 233, causing a translational frameshift with a predicted alternate stop codon (p.R78Lfs*128). This variant has been reported in a whole exome sequencing cohort and a familial hypercholesterolemia (FH) cohort (Di Taranto MD et al. Clin Genet, 2021 Nov;100:529-541; Dewey FE et al. Science, 2016 Dec;354:). This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). 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. -

Computational scores

Source: dbNSFP v4.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

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

Publications

LitVar

Other links and lift over

dbSNP: rs1057516129; hg19: chr19-11213381;