rs875989903

Variant names:

• chr19-11105553-G-GT
• rs875989903
• NM_000527.5:c.648dupT

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_000527.5(LDLR):​c.648dupT​(p.Asp217fs) variant causes a frameshift, stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,460,952 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. D217D) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: LDLR NM_000527.5 frameshift, stop_gained
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:8
• Conservation: PhyloP100: -1.05
• Publications: 3 publications found

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 Gene-Disease associations (from GenCC):

• hypercholesterolemia, familial, 1

  Inheritance: AD, SD Classification: DEFINITIVE, STRONG Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae), Laboratory for Molecular Medicine, ClinGen
• homozygous familial hypercholesterolemia

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Pathogenic. The variant received 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 19-11105553-G-GT is Pathogenic according to our data. Variant chr19-11105553-G-GT is described in ClinVar as [Likely_pathogenic]. Clinvar id is 226328.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
LDLR	NM_000527.5	c.648dupT	p.Asp217fs	frameshift_variant, stop_gained	Exon 4 of 18	ENST00000558518.6	NP_000518.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
LDLR	ENST00000558518.6	c.648dupT	p.Asp217fs	frameshift_variant, stop_gained	Exon 4 of 18	1	NM_000527.5	ENSP00000454071.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1460952 Hom.: 0 Cov.: 33 AF XY: 0.00000138 AC XY: 1 AN XY: 726692

African (AFR) AF: 0.00 AC: 0 AN: 33474

American (AMR) AF: 0.00 AC: 0 AN: 44718

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26132

East Asian (EAS) AF: 0.00 AC: 0 AN: 39680

South Asian (SAS) AF: 0.00 AC: 0 AN: 86242

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53018

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5712

European-Non Finnish (NFE) AF: 9.00e-7 AC: 1 AN: 1111624

Other (OTH) AF: 0.00 AC: 0 AN: 60352

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:8

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hypercholesterolemia, familial, 1 Pathogenic:5

Mar 25, 2016

LDLR-LOVD, British Heart Foundation

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: literature only

- -

May 24, 2021

Laboratory of molecular diagnosis of dyslipidemias, Università egli studi di Napoli Federico II

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Aug 14, 2014

Cardiovascular Genetics Laboratory, PathWest Laboratory Medicine WA - Fiona Stanley Hospital

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Mar 30, 2017

U4M - Lille University & CHRU Lille, Université de Lille - CHRU de Lille

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

-

Robarts Research Institute, Western University

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

not provided Pathogenic:1

Feb 26, 2019

Molecular Diagnostic Laboratory for Inherited Cardiovascular Disease, Montreal Heart Institute

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Cardiovascular phenotype Pathogenic:1

Oct 05, 2024

Ambry Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.648dupT pathogenic mutation, located in coding exon 4 of the LDLR gene, results from a duplication of T at nucleotide position 648, causing a translational frameshift with a predicted alternate stop codon (p.D217*). This variant has been reported in association with familial hypercholesterolemia (FH) (Defesche JC et al. J Clin Lipidol, 2017 Sep;11:1338-1346.e7; Guardamagna O et al. J Pediatr, 2009 Aug;155:199-204.e2; Di Taranto MD et al. Clin Genet, 2021 Nov;100:529-541). 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. -

Familial hypercholesterolemia Pathogenic:1

Jul 14, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This premature translational stop signal has been observed in individual(s) with hypercholesterolemia (PMID: 19446849). This variant is not present in population databases (gnomAD no frequency). This sequence change creates a premature translational stop signal (p.Asp217*) 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). ClinVar contains an entry for this variant (Variation ID: 226328). For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
PhyloP100		-1.0
Mutation Taster		=0/200	disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs875989903; hg19: chr19-11216229;