19-11105307-G-T

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PM1 PM2 PM5 PP3_Strong PP5_Very_Strong

The NM_000527.5(LDLR):c.401G>T(p.Cys134Phe) 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 Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. C134G) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 33)
• Consequence: LDLR NM_000527.5 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:5
• Conservation: PhyloP100: 9.88

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 18 ACMG points.

• PM1: In a hotspot region, there are 11 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 8 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 chr19-11105306-T-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 226322.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.996
• PP5: Variant 19-11105307-G-T is Pathogenic according to our data. Variant chr19-11105307-G-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 251204.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr19-11105307-G-T is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
LDLR	NM_000527.5	c.401G>T	p.Cys134Phe	missense_variant	4/18	ENST00000558518.6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
LDLR	ENST00000558518.6	c.401G>T	p.Cys134Phe	missense_variant	4/18	1	NM_000527.5	P3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:5

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hypercholesterolemia, familial, 1 Pathogenic:2

Likely pathogenic, criteria provided, single submitter	research	Iberoamerican FH Network	Mar 01, 2016	- -
Likely pathogenic, criteria provided, single submitter	literature only	LDLR-LOVD, British Heart Foundation	Mar 25, 2016	- -

Familial hypercholesterolemia Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Invitae	May 29, 2020	This variant is not present in population databases (ExAC no frequency). This sequence change replaces cysteine with phenylalanine at codon 134 of the LDLR protein (p.Cys134Phe). The cysteine residue is highly conserved and there is a large physicochemical difference between cysteine and phenylalanine. This variant has been observed in individual(s) with familial hypercholesterolemia (PMID: 10978268, 11462246, 18718593). This variant is also known as C113F in the literature. ClinVar contains an entry for this variant (Variation ID: 251204). 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 disruptive, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. For these reasons, this variant has been classified as Pathogenic. This variant disrupts the p.Cys134 amino acid residue in LDLR. Other variant(s) that disrupt this residue have been observed in individuals with LDLR-related conditions (PMID: 23375686, 11462246, 25921077, 10735632), which suggests that this may be a clinically significant amino acid residue. This variant affects a cysteine residue located within an LDLRA or epidermal-growth-factor (EGF)-like domains of the LDLR protein. Cysteine residues in these domains have been shown to be involved in the formation of disulfide bridges, which are critical for protein structure and stability (PMID: 7548065, 7603991, 7979249). In addition, missense substitutions within the LDLRA and EGF-like domains affecting cysteine residues are overrepresented among patients with hypercholesterolemia (PMID: 18325082). -
Likely pathogenic, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Mar 12, 2019	This missense variant (also known as p.Cys113Phe in the mature protein and as FH Alessandria) is located in the third LDLR type A repeat of the ligand binding domain 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 the RNA splicing. Although functional assays have not been performed for this variant, it changes one of the functionally critical cysteine residues that form intra-repeat disulfide bonds in the ligand binding domain (PMID: 15952897) and is expected to have deleterious impact on the LDLR protein folding and stability. This variant has been reported in three individuals with hypercholesterolemia in Italy, Germany, and Japan (PMID: 10978268 11462246 18718593, 23375686). This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). Based on available evidence this variant is classified as Likely Pathogenic. -

not provided Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

GeneDx

Sep 11, 2023

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Also known as p.(C113F); This variant is associated with the following publications: (PMID: 30583242, 34906454, 2988123, 12459547, 23375686, 31491741, 32331935, 34037665, 11462246, 10978268, 18718593) -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.58	D
BayesDel_noAF	Pathogenic	0.59
Cadd	Pathogenic	27
Dann	Uncertain	0.99
DEOGEN2	Pathogenic	0.98	D;.;.;.
Eigen	Pathogenic	0.95
Eigen_PC	Pathogenic	0.77
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Pathogenic	0.99	D;D;D;D
M_CAP	Pathogenic	0.81	D
MetaRNN	Pathogenic	1.0	D;D;D;D
MetaSVM	Pathogenic	0.91	D
MutationAssessor	Pathogenic	4.6	H;.;.;H
MutationTaster	Benign	1.0	D;D;D;D;D;D;D
PrimateAI	Uncertain	0.67	T
PROVEAN	Pathogenic	-10	D;D;D;D
Sift	Pathogenic	0.0	D;D;D;D
Sift4G	Pathogenic	0.0	D;D;D;D
Polyphen		1.0	D;.;.;.
Vest4		0.99
MutPred		0.95		Loss of catalytic residue at L135 (P = 0.0436);Loss of catalytic residue at L135 (P = 0.0436);.;Loss of catalytic residue at L135 (P = 0.0436);
MVP		1.0
MPC		1.0
ClinPred		1.0	D
GERP RS		5.4
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.2
Varity_R		0.99
gMVP		1.0

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs879254514; hg19: chr19-11215983;