Genetic Variant LDLR:p.Cys340Phe (chr19-11110730-G-T) – ACMG Classification: Pathogenic (19 pts)

Variant summary

Our verdict is Pathogenic. The variant received 19 ACMG points: 19P and 0B. PM1PM2PM5PP2PP3_StrongPP5_Very_Strong

The NM_000527.5(LDLR):c.1019G>T(p.Cys340Phe) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000031 in 1,613,720 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. C340W) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000027 ( 0 hom. )

Consequence

LDLR
NM_000527.5 missense

Scores

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3

Conservation

PhyloP100: 9.65

Publications

6 publications found

Variant links:

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]

LDLR Gene-Disease associations (from GenCC):

hypercholesterolemia, familial, 1
Inheritance: AD, SD Classification: DEFINITIVE, STRONG Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae), Laboratory for Molecular Medicine, ClinGen
homozygous familial hypercholesterolemia
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

LDLR links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 19 ACMG points.

PM1

In a hotspot region, there are 20 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 3 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 chr19-11110731-C-G is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 251601.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

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, 0.997

PP5

Variant 19-11110730-G-T is Pathogenic according to our data. Variant chr19-11110730-G-T is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 977987.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000527.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein
LDLR	NM_000527.5	MANE Select	c.1019G>T	p.Cys340Phe	missense	Exon 7 of 18	NP_000518.1
LDLR	NM_001195798.2		c.1019G>T	p.Cys340Phe	missense	Exon 7 of 18	NP_001182727.1
LDLR	NM_001195799.2		c.896G>T	p.Cys299Phe	missense	Exon 6 of 17	NP_001182728.1

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein
LDLR	ENST00000558518.6	TSL:1 MANE Select	c.1019G>T	p.Cys340Phe	missense	Exon 7 of 18	ENSP00000454071.1
LDLR	ENST00000252444.10	TSL:1	c.1277G>T	p.Cys426Phe	missense	Exon 7 of 18	ENSP00000252444.6
LDLR	ENST00000558013.5	TSL:1	c.1019G>T	p.Cys340Phe	missense	Exon 7 of 18	ENSP00000453346.1

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152196

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.000207

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.00000797

AC:

AN:

251028

AF XY:

0.0000147

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000274

AC:

AN:

1461524

Hom.:

Cov.:

AF XY:

0.00000550

AC XY:

AN XY:

727064

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33478

American (AMR)

AF:

0.00

AC:

AN:

44722

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26134

East Asian (EAS)

AF:

0.00

AC:

AN:

39694

South Asian (SAS)

AF:

0.0000464

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53116

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

1111964

Other (OTH)

AF:

0.00

AC:

AN:

60390

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.438

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152196

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74336

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41462

American (AMR)

AF:

0.00

AC:

AN:

15266

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5192

South Asian (SAS)

AF:

0.000207

AC:

AN:

4830

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10618

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

68042

Other (OTH)

AF:

0.00

AC:

AN:

2088

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.675

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

Alfa

AF:

0.00

Hom.:

ExAC

AF:

0.00000824

AC:

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Hypercholesterolemia, familial, 1

Pathogenic:2

Dec 23, 2024

3billion

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The variant is observed at an extremely low frequency in the gnomAD v4.1.0 dataset (total allele frequency: <0.001%). Predicted Consequence/Location: The variant is located in a mutational hot spot and/or well-established functional domain in which established pathogenic variants have been reported (PMID: 34906454). In silico tool predictions suggest damaging effect of the variant on gene or gene product [REVEL: 0.92 (>=0.6, sensitivity 0.68 and specificity 0.92); 3Cnet: 0.99 (>=0.6, sensitivity 0.72 and precision 0.9)]. The same nucleotide change resulting in the same amino acid change has been previously reported as pathogenic/likely pathogenic with strong evidence (ClinVar ID: VCV000977987 /PMID: 27050191). Different missense changes at the same codon (p.Cys340Leu, p.Cys340Trp, p.Cys340Tyr) have been reported as pathogenic/likely pathogenic with strong evidence (ClinVar ID: VCV000251599, VCV000251600, VCV000251601 /PMID: 15241806, 20809525, 22881376). Therefore, this variant is classified as Pathogenic according to the recommendation of ACMG/AMP guideline.

Mar 10, 2019

Brunham Lab, Centre for Heart and Lung Innovation, University of British Columbia

Significance:Likely pathogenic

Review Status:criteria provided, single submitter

Collection Method:research

Familial hypercholesterolemia

Pathogenic:1

May 30, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Likely pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This variant disrupts the p.Cys340 amino acid residue in LDLR. Other variant(s) that disrupt this residue have been observed in individuals with LDLR-related conditions (PMID: 23535506, 20809525, 30592178), which suggests that this may be a clinically significant amino acid residue. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. 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). 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. This variant has been observed in individual(s) with familial hypercholesterolemia (PMID: 28964736, Invitae). ClinVar contains an entry for this variant (Variation ID: 977987). This variant is present in population databases (rs755757866, ExAC 0.006%). This sequence change replaces cysteine with phenylalanine at codon 340 of the LDLR protein (p.Cys340Phe). The cysteine residue is highly conserved and there is a large physicochemical difference between cysteine and phenylalanine.

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.98

BayesDel_addAF

Pathogenic

0.45

BayesDel_noAF

Pathogenic

0.60

CADD

Pathogenic

(source)

DANN

Uncertain

0.99

DEOGEN2

Pathogenic

0.98

Eigen

Pathogenic

0.98

Eigen_PC

Pathogenic

0.79

FATHMM_MKL

Pathogenic

1.0

LIST_S2

Pathogenic

1.0

M_CAP

Pathogenic

0.74

MetaRNN

Pathogenic

1.0

MetaSVM

Pathogenic

1.1

MutationAssessor

Pathogenic

4.5

PhyloP100

9.7

PrimateAI

Uncertain

0.64

PROVEAN

Pathogenic

-11

REVEL

Pathogenic

0.92

Sift

Uncertain

0.0010

Sift4G

Pathogenic

0.0

Polyphen

1.0

Vest4

0.99

MutPred

0.99

Gain of loop (P = 0.2045)

MVP

1.0

MPC

1.0

ClinPred

1.0

GERP RS

5.4

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.1

Varity_R

0.99

gMVP

1.0

Mutation Taster

=0/100

disease causing (ClinVar)

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over