rs875989905

Positions:

• chr19-11105562-GC-G

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.660del​(p.Asp221ThrfsTer44) 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 Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 33)
• Consequence: LDLR NM_000527.5 frameshift
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:8
• Conservation: PhyloP100: -1.25

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]

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 19-11105562-GC-G is Pathogenic according to our data. Variant chr19-11105562-GC-G is described in ClinVar as [Pathogenic]. Clinvar id is 226330.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr19-11105562-GC-G is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
LDLR	NM_000527.5	c.660del	p.Asp221ThrfsTer44	frameshift_variant	4/18	ENST00000558518.6	NP_000518.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
LDLR	ENST00000558518.6	c.660del	p.Asp221ThrfsTer44	frameshift_variant	4/18	1	NM_000527.5	ENSP00000454071	P3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:8

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hypercholesterolemia, familial, 1 Pathogenic:4

Pathogenic, no assertion criteria provided	research	Laboratorium voor Moleculaire Diagnostiek Experimentele Vasculaire Geneeskunde, Academisch Medisch Centrum	-	- -
Pathogenic, criteria provided, single submitter	research	Brunham Lab, Centre for Heart and Lung Innovation, University of British Columbia	May 11, 2019	- -
Pathogenic, no assertion criteria provided	clinical testing	Cardiovascular Genetics Laboratory, PathWest Laboratory Medicine WA - Fiona Stanley Hospital	May 05, 2014	- -
Pathogenic, criteria provided, single submitter	literature only	LDLR-LOVD, British Heart Foundation	Mar 25, 2016	- -

Familial hypercholesterolemia Pathogenic:2

Pathogenic, no assertion criteria provided	clinical testing	Natera, Inc.	Dec 07, 2020	- -
Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Feb 10, 2021	For these reasons, this variant has been classified as Pathogenic. This variant has been observed in several individuals affected with familial hypercholesterolemia (PMID: 9678702, 11139254, 22883975, 11462246, 15556094). This variant is also known as P199fsX243, 657delC. ClinVar contains an entry for this variant (Variation ID: 226330). This variant is not present in population databases (ExAC no frequency). This sequence change creates a premature translational stop signal (p.Asp221Thrfs*44) 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). -

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

GeneDx

Dec 14, 2022

Frameshift variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss of function is a known mechanism of disease; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 34037665, 9678702) -

Cardiovascular phenotype Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Dec 13, 2023

The c.660delC (p.D221Tfs*44) alteration, located in exon 4 (coding exon 4) of the LDLR gene, consists of a deletion of one nucleotide at position 660, causing a translational frameshift with a predicted alternate stop codon after 44 amino acids. Frameshift alterations are typically deleterious in nature (Richards, 2015). This variant was not reported in population-based cohorts in the Genome Aggregation Database (gnomAD). This mutation (also described as c.657delC) has been reported in numerous familial hypercholesterolemia (FH) cohorts from a variety of ethnic backgrounds (Lee, 1998; Bochmann, 2001; Laurie, 2004; Bamimore, 2015; Hu, 2016). Based on the available evidence, this alteration is classified as pathogenic. -

Computational scores

Source: dbNSFP v4.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs875989905; hg19: chr19-11216238;