rs1555803887

chr19-11107464-A-Cchr19-11107464-A-G

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.890A>C(p.Asn297Thr) 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 Uncertain significance (★★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. N297H) 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 U:2
• Conservation: PhyloP100: 9.21

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 12 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 10 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 chr19-11107463-A-C is described in Lovd as [Likely_pathogenic].
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.89

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
LDLR	NM_000527.5	c.890A>C	p.Asn297Thr	missense_variant	6/18	ENST00000558518.6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
LDLR	ENST00000558518.6	c.890A>C	p.Asn297Thr	missense_variant	6/18	1	NM_000527.5	P3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: reviewed by expert panel

Submissions by phenotype

Hypercholesterolemia, familial, 1 Uncertain:2

Uncertain significance, reviewed by expert panel	curation	ClinGen Familial Hypercholesterolemia Variant Curation Expert Panel	Feb 14, 2022	The NM_000527.5(LDLR):c.890A>C (p.Asn297Thr) variant is classified as Uncertain significance - insufficient evidence for Familial Hypercholesterolemia by applying evidence codes PM2, BS3, PP3 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 is absent from gnomAD (gnomAD v2.1.1), so PM2 is Met. BS3 - Level 1 assays: PMID 28645073: Heterologous cells (CHO-ldlA7), WB, FACS and CLSM assays - result - Normal (91%) expression, binding (97%) and uptake (100%) ---- functional study is consistent with no damaging effect (whole cycle is above 90%), so BS3 is Met. PP3 - REVEL = 0.785. It is above 0.75, so PP3 is Met. -
Uncertain significance, criteria provided, single submitter	research	Fundacion Hipercolesterolemia Familiar	Mar 01, 2016	- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.77
BayesDel_addAF	Pathogenic	0.25	D
BayesDel_noAF	Uncertain	0.12
Cadd	Uncertain	25
Dann	Uncertain	0.99
DEOGEN2	Pathogenic	0.87	D;.;.;.;.;.
Eigen	Pathogenic	0.74
Eigen_PC	Uncertain	0.62
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.90	D;D;D;D;D;D
M_CAP	Pathogenic	0.67	D
MetaRNN	Pathogenic	0.89	D;D;D;D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	3.6	H;.;.;.;.;H
MutationTaster	Benign	1.0	D;D;D;D;D;D;D
PrimateAI	Benign	0.34	T
PROVEAN	Uncertain	-3.9	D;D;D;D;D;D
Sift	Uncertain	0.0020	D;D;D;D;D;D
Sift4G	Uncertain	0.0050	D;D;D;D;D;D
Polyphen		0.85	P;.;.;.;.;.
Vest4		0.42
MutPred		0.75		Gain of phosphorylation at N297 (P = 0.0657);Gain of phosphorylation at N297 (P = 0.0657);.;.;.;Gain of phosphorylation at N297 (P = 0.0657);
MVP		1.0
MPC		0.67
ClinPred		0.99	D
GERP RS		5.3
Varity_R		0.95
gMVP		0.92

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: rs1555803887; hg19: chr19-11218140;