rs777321035

chr19-11105410-C-Achr19-11105410-C-T

Variant summary

Our verdict is Pathogenic. Variant got 11 ACMG points: 11P and 0B. PM1 PM2 PM5 PP3_Strong PP5

The NM_000527.5(LDLR):c.504C>A(p.Asp168Glu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,722 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 Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. D168A) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: LDLR NM_000527.5 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:3 U:1
• Conservation: PhyloP100: -0.142

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 11 ACMG points.

• PM1: In a hotspot region, there are 13 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 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 chr19-11105409-A-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 375785.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.992
• PP5: Variant 19-11105410-C-A is Pathogenic according to our data. Variant chr19-11105410-C-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 251261.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=3, Uncertain_significance=1}. Variant chr19-11105410-C-A is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
LDLR	NM_000527.5	c.504C>A	p.Asp168Glu	missense_variant	4/18	ENST00000558518.6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
LDLR	ENST00000558518.6	c.504C>A	p.Asp168Glu	missense_variant	4/18	1	NM_000527.5	P3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.00000796 AC: 2 AN: 251292 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135868

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000578

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS 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: 0.00000137 AC: 2 AN: 1461722 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 727166

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000447

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

Alfa AF: 0.00209 Hom.: 0

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:3 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Hypercholesterolemia, familial, 1 Pathogenic:2 Uncertain:1

Likely pathogenic, criteria provided, single submitter	clinical testing	Robarts Research Institute, Western University	-	- -
Likely pathogenic, criteria provided, single submitter	literature only	LDLR-LOVD, British Heart Foundation	Mar 25, 2016	- -
Uncertain significance, criteria provided, single submitter	curation	Broad Center for Mendelian Genomics, Broad Institute of MIT and Harvard	Jan 22, 2020	The p.Asp168Glu variant in LDLR has been reported in one Turkish individual in the homozygous state and in one individual in the heterozygous state with Familial Hypercholesterolemia (PMID: 15823276, 27765764), and has been identified in 0.005782% (2/34592) of Latino chromosomes by the Genome Aggregation Database (gnomAD, http://gnomad.broadinstitute.org; dbSNP rs777321035). Please note that for diseases with clinical variability, or reduced penetrance, pathogenic variants may be present at a low frequency in the general population. This variant has also been reported likely pathogenic in ClinVar (Variation ID: 251261). Computational prediction tools and conservation analyses suggest that this variant may impact the protein, though this information is not predictive enough to determine pathogenicity. Two additional likely pathogenic variants, resulting in a different amino acid change at the same position, p.Asp168Asn and p.Asp168His, have been reported in association with disease in the literature, supporting that a change at this position may not be tolerated (PMID: 8462973, 28966723, 8882879, 28104544, 16250003, 20828696, 27784735, 25647241, 25545329, 16389549, 28379029, 16205024, 19007590, 15556094, 9259195, 22859806, 9678702 /Variation ID: 183136, 251258). The phenotype of a 5 year old Turkish individual homozygous for this variant is highly specific for Familial Hypercholesterolemia based on tendon xanthoma, arcus cornia, and cholesterol levels consistent with disease (PMID: 15823276). Homozygotes with pathogenic variants in this gene are known to have a more severe and earlier onset phenotype than heterozygotes. In summary, while there is some suspicion for a pathogenic role, the clinical significance of this variant is uncertain. ACMG/AMP Criteria applied: PM5, PP4, PS4_Supporting, PP3 (Richards 2015). -

Familial hypercholesterolemia Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Invitae

Aug 19, 2019

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 disrupts the p.Asp168 amino acid residue in LDLR. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 8462973, 28104544, 20828696, 16250003). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. 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 several individuals affected with familial hypercholesterolemia (PMID: 15823276, 27765764, Invitae). ClinVar contains an entry for this variant (Variation ID: 251261). This variant is also described as Asp147Glu (D147E) in the literature. This variant is present in population databases (rs777321035, ExAC 0.009%). This sequence change replaces aspartic acid with glutamic acid at codon 168 of the LDLR protein (p.Asp168Glu). The aspartic acid residue is highly conserved and there is a small physicochemical difference between aspartic acid and glutamic acid. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.38	D
BayesDel_noAF	Pathogenic	0.49
Cadd	Benign	15
Dann	Uncertain	1.0
DEOGEN2	Pathogenic	0.96	D;.;.;.
Eigen	Benign	0.11
Eigen_PC	Benign	-0.16
FATHMM_MKL	Uncertain	0.95	D
LIST_S2	Uncertain	0.92	D;D;D;D
M_CAP	Pathogenic	0.89	D
MetaRNN	Pathogenic	0.99	D;D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	4.1	H;.;.;H
MutationTaster	Benign	1.0	D;D;D;D;D;D;D
PrimateAI	Uncertain	0.59	T
PROVEAN	Uncertain	-3.6	D;D;D;D
Sift	Uncertain	0.0010	D;D;D;D
Sift4G	Uncertain	0.0020	D;D;D;D
Polyphen		1.0	D;.;.;.
Vest4		0.72
MutPred		0.98		Gain of catalytic residue at D168 (P = 0.1916);Gain of catalytic residue at D168 (P = 0.1916);.;Gain of catalytic residue at D168 (P = 0.1916);
MVP		1.0
MPC		0.78
ClinPred		1.0	D
GERP RS		0.075
Varity_R		0.98
gMVP		1.0

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: rs777321035; hg19: chr19-11216086;