rs879254849

Variant names:

• chr19-11113359-T-C
• rs879254849
• NM_000527.5:c.1268T>C

Variant summary

Our verdict is Pathogenic. The variant received 17 ACMG points: 17P and 0B. PM1 PM2 PM5 PP2 PP3_Moderate PP5_Very_Strong

The NM_000527.5(LDLR):​c.1268T>C​(p.Ile423Thr) variant causes a missense change. The variant allele was found at a frequency of 0.00000274 in 1,461,698 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 (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. I423M) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 29)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: LDLR NM_000527.5 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:7
• Conservation: PhyloP100: 6.19
• Publications: 10 publications found

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]

MIR6886 (HGNC:50121): (microRNA 6886) microRNAs (miRNAs) are short (20-24 nt) non-coding RNAs that are involved in post-transcriptional regulation of gene expression in multicellular organisms by affecting both the stability and translation of mRNAs. miRNAs are transcribed by RNA polymerase II as part of capped and polyadenylated primary transcripts (pri-miRNAs) that can be either protein-coding or non-coding. The primary transcript is cleaved by the Drosha ribonuclease III enzyme to produce an approximately 70-nt stem-loop precursor miRNA (pre-miRNA), which is further cleaved by the cytoplasmic Dicer ribonuclease to generate the mature miRNA and antisense miRNA star (miRNA*) products. The mature miRNA is incorporated into a RNA-induced silencing complex (RISC), which recognizes target mRNAs through imperfect base pairing with the miRNA and most commonly results in translational inhibition or destabilization of the target mRNA. The RefSeq represents the predicted microRNA stem-loop. [provided by RefSeq, Sep 2009]

ACMG classification

Our verdict: Pathogenic. The variant received 17 ACMG points.

• PM1: In a hotspot region, there are 22 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 13 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 chr19-11113360-C-G is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 431525.
• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 678 curated pathogenic missense variants (we use a threshold of 10). The gene has 92 curated benign missense variants. Gene score misZ: 0.12407 (below the threshold of 3.09). Trascript score misZ: 0.59338 (below the threshold of 3.09). GenCC associations: The gene is linked to hypercholesterolemia, familial, 1, homozygous familial hypercholesterolemia.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.935
• PP5: Variant 19-11113359-T-C is Pathogenic according to our data. Variant chr19-11113359-T-C is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 251760.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
LDLR	NM_000527.5	c.1268T>C	p.Ile423Thr	missense_variant	Exon 9 of 18	ENST00000558518.6	NP_000518.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
LDLR	ENST00000558518.6	c.1268T>C	p.Ile423Thr	missense_variant	Exon 9 of 18	1	NM_000527.5	ENSP00000454071.1

Frequencies

GnomAD3 genomes Cov.: 29

GnomAD4 exome AF: 0.00000274 AC: 4 AN: 1461698 Hom.: 0 Cov.: 33 AF XY: 0.00000413 AC XY: 3 AN XY: 727164

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.0000188 AC: 1 AN: 53246

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5766

European-Non Finnish (NFE) AF: 0.00000180 AC: 2 AN: 1111996

Other (OTH) AF: 0.0000166 AC: 1 AN: 60392

GnomAD4 genome Cov.: 29

Alfa AF: 0.00 Hom.: 0

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:7

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hypercholesterolemia, familial, 1 Pathogenic:5

Dec 16, 2016

Centre de Génétique Moléculaire et Chromosomique, Unité de génétique de l'Obésité et des Dyslipidémies, APHP, GH Hôpitaux Universitaires Pitié-Salpêtrière / Charles-Foix

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

subjects mutated among 2600 FH index cases screened = 15 , family members = 6 with co-segregation / variant systematically associated with c.798T>A, p.Asp266Glu / Software predictions: Conflicting -

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Laboratorium voor Moleculaire Diagnostiek Experimentele Vasculaire Geneeskunde, Academisch Medisch Centrum

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: research

- -

Mar 25, 2016

LDLR-LOVD, British Heart Foundation

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: literature only

- -

Mar 01, 2016

Cardiovascular Research Group, Instituto Nacional de Saude Doutor Ricardo Jorge

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: curation;literature only

- -

-

Juno Genomics, Hangzhou Juno Genomics, Inc

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

PM2_Supporting+PS3+PS4_Moderate+PP4+PM3 -

Cardiovascular phenotype Pathogenic:1

Mar 25, 2025

Ambry Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.1268T>C (p.I423T) alteration is located in exon 9 (coding exon 9) of the LDLR gene. This alteration results from a T to C substitution at nucleotide position 1268, causing the isoleucine (I) at amino acid position 423 to be replaced by a threonine (T). This variant was not reported in population-based cohorts in the Genome Aggregation Database (gnomAD). This variant (also referred to as p.I402T) was identified in one or more individuals with features consistent with familial hypercholesterolemia and segregated with disease in at least one family (Ekström, 2000; Khoo, 2000; Amsellem, 2002; Wu, 2014; Ambry internal data). In an assay testing LDLR function, this variant showed a functionally abnormal result (Ekström, 2000). This amino acid position is not well conserved in available vertebrate species. This alteration is predicted to be deleterious by in silico analysis. Based on the available evidence, this alteration is classified as pathogenic. -

Familial hypercholesterolemia Pathogenic:1

Mar 04, 2020

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces isoleucine with threonine at codon 423 of the LDLR protein (p.Ile423Thr). The isoleucine residue is highly conserved and there is a moderate physicochemical difference between isoleucine and threonine. This variant is not present in population databases (ExAC no frequency). This variant has been observed in individual(s) with familial hypercholesterolemia (PMID: 7635461, 24722143, 11005141, 10884919, Invitae). It has also been observed to segregate with disease in related individuals. This variant is also known as p.I402T in the literature. ClinVar contains an entry for this variant (Variation ID: 251760, 430765). This variant has been reported to affect LDLR protein function (PMID: 10884919). For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.78
BayesDel_addAF	Pathogenic	0.35	D
BayesDel_noAF	Pathogenic	0.27
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.84	D;.;.;.;.;.
Eigen	Uncertain	0.55
Eigen_PC	Uncertain	0.55
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.95	D;D;D;D;D;D
M_CAP	Pathogenic	0.70	D
MetaRNN	Pathogenic	0.93	D;D;D;D;D;D
MetaSVM	Uncertain	0.77	D
MutationAssessor	Benign	1.2	L;.;.;.;.;L
PhyloP100		6.2
PrimateAI	Uncertain	0.63	T
PROVEAN	Uncertain	-3.9	D;D;D;D;D;D
REVEL	Pathogenic	0.90
Sift	Uncertain	0.0010	D;D;D;D;D;D
Sift4G	Uncertain	0.013	D;D;D;D;D;D
Polyphen		0.80	P;.;.;.;.;.
Vest4		0.53
MutPred		0.84		Gain of disorder (P = 0.0151);Gain of disorder (P = 0.0151);.;.;.;Gain of disorder (P = 0.0151);
MVP		1.0
MPC		0.84
ClinPred		0.99	D
GERP RS		4.9
Varity_R		0.69
gMVP		0.99
Mutation Taster		=1/99	disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs879254849; hg19: chr19-11224035;