19-11106640-G-C

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM1 PM2 PM5 PP3_Moderate

The NM_000527.5(LDLR):c.770G>C(p.Arg257Pro) variant causes a missense change involving the alteration of a non-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 Uncertain significance (★★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R257H) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: LDLR NM_000527.5 missense
• Clinical Significance: Uncertain significance reviewed by expert panel P:1 U:1
• Conservation: PhyloP100: -0.274

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 Likely_pathogenic. Variant got 8 ACMG points.

• PM1: In a hotspot region, there are 9 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 7 uncertain 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 chr19-11106639-C-T is described in Lovd as [Likely_pathogenic].
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.873

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
LDLR	NM_000527.5	c.770G>C	p.Arg257Pro	missense_variant	5/18	ENST00000558518.6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
LDLR	ENST00000558518.6	c.770G>C	p.Arg257Pro	missense_variant	5/18	1	NM_000527.5	P3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Pathogenic:1 Uncertain:1

Revision: reviewed by expert panel

Submissions by phenotype

Hypercholesterolemia, familial, 1 Pathogenic:1 Uncertain:1

Uncertain significance, reviewed by expert panel	curation	ClinGen Familial Hypercholesterolemia Variant Curation Expert Panel	Aug 29, 2022	The NM_000527.5(LDLR):c.770G>C (p.Arg257Pro) variant is classified as Uncertain significance - insufficient evidence for Familial Hypercholesterolemia by applying evidence code PM2 as defined by the ClinGen Familial Hypercholesterolemia Expert Panel LDLR-specific variant curation guidelines (https://doi.org/10.1016/j.gim.2021.09.012). The supporting evidence is as follows: PM2 - This variant was not identified in gnomAD (gnomAD v2.1.1). -
Pathogenic, no assertion criteria provided	research	Laboratorium voor Moleculaire Diagnostiek Experimentele Vasculaire Geneeskunde, Academisch Medisch Centrum	-	- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.71
BayesDel_addAF	Pathogenic	0.20	D
BayesDel_noAF	Uncertain	0.040
Cadd	Benign	16
Dann	Uncertain	0.98
DEOGEN2	Pathogenic	0.84	D;.;.;.;.
Eigen	Benign	-0.59
Eigen_PC	Benign	-0.82
FATHMM_MKL	Uncertain	0.87	D
LIST_S2	Uncertain	0.96	D;D;D;D;D
M_CAP	Pathogenic	0.64	D
MetaRNN	Pathogenic	0.87	D;D;D;D;D
MetaSVM	Uncertain	0.60	D
MutationAssessor	Benign	1.7	L;.;.;.;L
MutationTaster	Benign	1.0	N;N;N;N;N;N;N
PrimateAI	Benign	0.21	T
PROVEAN	Uncertain	-2.6	D;N;D;N;D
Sift	Uncertain	0.029	D;D;D;T;D
Sift4G	Benign	0.12	T;T;T;D;T
Polyphen		0.80	P;.;.;.;.
Vest4		0.62
MutPred		0.62		Gain of ubiquitination at K262 (P = 0.0659);Gain of ubiquitination at K262 (P = 0.0659);.;.;Gain of ubiquitination at K262 (P = 0.0659);
MVP		1.0
MPC		0.86
ClinPred		0.65	D
GERP RS		-2.9
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.98
gMVP		0.90

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: rs757808215; hg19: chr19-11217316;