rs879254437

Positions:

• chr19-11102677-C-A

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.204C>A​(p.Cys68Ter) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,468 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: LDLR NM_000527.5 stop_gained
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 1.93

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 19-11102677-C-A is Pathogenic according to our data. Variant chr19-11102677-C-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 251077.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr19-11102677-C-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
LDLR	NM_000527.5	c.204C>A	p.Cys68Ter	stop_gained	3/18	ENST00000558518.6	NP_000518.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
LDLR	ENST00000558518.6	c.204C>A	p.Cys68Ter	stop_gained	3/18	1	NM_000527.5	ENSP00000454071	P3

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461468 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727048

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 31

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Homozygous familial hypercholesterolemia Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Apr 02, 2019

The p.Cys68X variant in LDLR (also reported as p.Cys47X in the literature) has been reported in the heterozygous state in 1 individual with familial hypercholesterolemia (FH; Tosi 2007) and has also been reported in ClinVar (Variation ID: 251077). It was absent from large population studies. This nonsense variant leads to a premature termination codon at position 68, which is predicted to lead to a truncated or absent protein. Loss of function of the LDLR gene is an established disease mechanism in autosomal dominant FH. In summary, this variant meets criteria to be classified as likely pathogenic for autosomal dominant FH. ACMG/AMP Criteria applied: PVS1, PM2. -

Hypercholesterolemia, familial, 1 Pathogenic:1

Pathogenic, criteria provided, single submitter

literature only

LDLR-LOVD, British Heart Foundation

Mar 25, 2016

- -

Familial hypercholesterolemia Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Aug 30, 2023

This sequence change creates a premature translational stop signal (p.Cys68*) 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 not present in population databases (gnomAD no frequency). This premature translational stop signal has been observed in individuals with familial hypercholesterolemia (PMID: 17094996, 23680767). This variant is also known as C47X. ClinVar contains an entry for this variant (Variation ID: 251077). For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.53
CADD	Pathogenic	34
DANN	Uncertain	0.99
Eigen	Uncertain	0.49
Eigen_PC	Uncertain	0.30
FATHMM_MKL	Uncertain	0.96	D
MutationTaster	Benign	1.0	A;A;A;A;A;D;D
Vest4		0.92
GERP RS		3.5

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: rs879254437; hg19: chr19-11213353;