19-11123324-T-G

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_000527.5(LDLR):c.2291T>G(p.Ile764Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,830 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. I764T) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: LDLR NM_000527.5 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: -1.72

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 Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.20375493).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
LDLR	NM_000527.5	c.2291T>G	p.Ile764Arg	missense_variant	15/18	ENST00000558518.6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
LDLR	ENST00000558518.6	c.2291T>G	p.Ile764Arg	missense_variant	15/18	1	NM_000527.5	P3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461830 Hom.: 0 Cov.: 34 AF XY: 0.00000138 AC XY: 1 AN XY: 727212

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: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Familial hypercholesterolemia Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Nov 05, 2019	This missense variant (also known as p.Ile743Arg in the mature protein) replaces isoleucine with arginine at codon 764 of the LDLR protein. Computational prediction tool suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold ≤0.5, PMID: 27666373). Splice site prediction tools suggest that this variant may not impact RNA splicing. To our knowledge, functional studies have not been performed for this variant. This variant has not 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). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -
Uncertain significance, criteria provided, single submitter	clinical testing	Invitae	Apr 16, 2021	In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. This variant has not been reported in the literature in individuals with LDLR-related conditions. ClinVar contains an entry for this variant (Variation ID: 920005). This variant is not present in population databases (ExAC no frequency). This sequence change replaces isoleucine with arginine at codon 764 of the LDLR protein (p.Ile764Arg). The isoleucine residue is weakly conserved and there is a moderate physicochemical difference between isoleucine and arginine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.12
BayesDel_addAF	Uncertain	0.021	T
BayesDel_noAF	Benign	-0.21
Cadd	Benign	0.028
Dann	Benign	0.24
DEOGEN2	Benign	0.40	T;.;.;.;.;.
Eigen	Benign	-1.5
Eigen_PC	Benign	-1.6
FATHMM_MKL	Benign	0.19	N
LIST_S2	Benign	0.59	T;T;T;T;T;T
M_CAP	Pathogenic	0.33	D
MetaRNN	Benign	0.20	T;T;T;T;T;T
MetaSVM	Benign	-0.64	T
MutationAssessor	Benign	1.2	L;.;.;.;.;L
MutationTaster	Benign	1.0	N;N;N;N;N;N;N
PrimateAI	Benign	0.26	T
PROVEAN	Benign	-0.31	N;N;N;N;N;N
Sift	Benign	0.65	T;T;T;T;T;T
Sift4G	Benign	0.52	T;T;T;T;T;T
Polyphen		0.024	B;.;.;.;.;.
Vest4		0.17
MutPred		0.50		Gain of disorder (P = 0.0066);Gain of disorder (P = 0.0066);.;.;.;Gain of disorder (P = 0.0066);
MVP		0.84
MPC		0.38
ClinPred		0.061	T
GERP RS		-3.1
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.046
gMVP		0.84

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: rs759440817; hg19: chr19-11234000;