19-11116153-G-C

Position:

• chr19-11116153-G-C

Variant summary

Our verdict is Pathogenic. Variant got 11 ACMG points: 11P and 0B. PM1 PM2 PM5 PP3_Strong PP5

The NM_000527.5(LDLR):​c.1646G>C​(p.Gly549Ala) variant causes a missense 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. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G549D) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: LDLR NM_000527.5 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:1
• Conservation: PhyloP100: 9.79

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 11 ACMG points.

• PM1: In a repeat LDL-receptor class B 4 (size 43) in uniprot entity LDLR_HUMAN there are 54 pathogenic changes around while only 5 benign (92%) in NM_000527.5
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chrnull-null-null-null is described in UniProt as null.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.995
• PP5: Variant 19-11116153-G-C is Pathogenic according to our data. Variant chr19-11116153-G-C is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 920279.We mark this variant Likely_pathogenic, oryginal submissions are: {Uncertain_significance=1, Likely_pathogenic=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
LDLR	NM_000527.5	c.1646G>C	p.Gly549Ala	missense_variant	11/18	ENST00000558518.6	NP_000518.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
LDLR	ENST00000558518.6	c.1646G>C	p.Gly549Ala	missense_variant	11/18	1	NM_000527.5	ENSP00000454071.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Familial hypercholesterolemia Pathogenic:1 Uncertain:1

Likely pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Nov 29, 2022	In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. This variant disrupts the p.Gly549 amino acid residue in LDLR. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 23375686, 25487149, 25647241). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt LDLR protein function. ClinVar contains an entry for this variant (Variation ID: 920279). 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 replaces glycine, which is neutral and non-polar, with alanine, which is neutral and non-polar, at codon 549 of the LDLR protein (p.Gly549Ala). -
Uncertain significance, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Apr 29, 2019	This missense variant (also known as p.Gly528Ala in the mature protein) replaces glycine with alanine at codon 549 of the LDLR protein. Computational prediction tools and conservation analyses suggest that this variant may have deleterious impact on the protein function. Computational splicing tools suggest that this variant may not impact RNA splicing. To our knowledge, functional assays have not been performed for this variant nor has this variant been reported in individuals affected with familial hypercholesterolemia in the literature. This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). A different missense variant at the same codon, p.Gly549Asp, is known to cause familial hypercholesterolemia (Clinvar variation ID: 3698), suggesting that glycine at this position is important for the LDLR function. Although there is a suspicion that this variant may be associated with disease, additional studies are necessary to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.79
BayesDel_addAF	Pathogenic	0.41	D
BayesDel_noAF	Pathogenic	0.34
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.97	D;.;.;.;.;.
Eigen	Uncertain	0.59
Eigen_PC	Uncertain	0.41
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.97	D;D;D;D;D;D
M_CAP	Pathogenic	0.94	D
MetaRNN	Pathogenic	1.0	D;D;D;D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	3.5	M;.;.;.;.;M
PrimateAI	Uncertain	0.54	T
PROVEAN	Pathogenic	-5.7	D;D;D;D;D;D
REVEL	Pathogenic	0.87
Sift	Pathogenic	0.0	D;D;D;D;D;D
Sift4G	Pathogenic	0.0	D;D;D;D;D;D
Polyphen		1.0	D;.;.;.;.;.
Vest4		0.88
MutPred		0.99		Loss of sheet (P = 0.0457);Loss of sheet (P = 0.0457);.;.;.;Loss of sheet (P = 0.0457);
MVP		1.0
MPC		0.84
ClinPred		1.0	D
GERP RS		4.8
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.94
gMVP		0.98

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: rs28941776; hg19: chr19-11226829;