19-11107469-G-A

Position:

• chr19-11107469-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PS3_Supporting PM2 PP4 PS4_Supporting

This summary comes from the ClinGen Evidence Repository: The NM_000527.5 (LDLR): c.895G>A (p.Ala299Thr) variant is classified as Uncertain significance - insufficient evidence for Familial Hypercholesterolemia by applying evidence codes (PM2, PP4, PS4_Supporting, PS3_Supporting) 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 Met: PopMAX MAF = 0.00005 in East Asian population in gnomAD (gnomAD v2.1.1).PP4 Met: This variant meets PM2 and is identified in > 1 index cases who met clinical criteria for FH after alternative causes for high cholesterol were excluded. PS4_Supporting Met: Variant meets PM2 and is identified in 2 unrelated index cases who fulfil DLCN criteria for FH (1 case from Unidad de Biof´ısica , Centro Mixto CSIC-UPV/EHU and Departamento de Bioqu´ımica, Universidad del Pa´ıs Vasco, Bilbao, Spain, PMID 21990180; 1 case from Lipid Clinic, Fundación Jiménez Díaz, Madrid, Spain, PMID 19318025).PS3_Supporting Met: Heterozygous patient lymphocytes FACS assays (level 3 functional assay) showed normal cell surface localization, but 50% LDL-LDLR uptake and binding (Etxebarria et al, Unidad de Biof´ısica, Centro Mixto CSIC-UPV/EHU and Departamento de Bioqu´ımica, Universidad del Pa´ıs Vasco, Bilbao, Spain, PMID 21990180).PP3 not met: REVEL score = 0.543, which is below the threshold of 0.75. This variant does not creating de novo acceptor or donor site and is not predicted to alter splicing.PM5 not met: There is one other variant in the same codon: LDLR: NM_000527:c.895G>T (p.Ala299Ser) is classified as Uncertain significance - insufficient evidence by these guidelines. Therefore PM5 is not met. LINK:https://erepo.genome.network/evrepo/ui/classification/CA10585179/MONDO:0007750/013

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: LDLR NM_000527.5 missense
• Clinical Significance: Uncertain significance reviewed by expert panel P:2 U:2
• Conservation: PhyloP100: 0.794

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 Uncertain_significance. Variant got 5 ACMG points.

• PS3: For more information check the summary or visit ClinGen Evidence Repository.
• PS4: For more information check the summary or visit ClinGen Evidence Repository.
• PM2: For more information check the summary or visit ClinGen Evidence Repository.
• PP4: For more information check the summary or visit ClinGen Evidence Repository.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
LDLR	NM_000527.5	c.895G>A	p.Ala299Thr	missense_variant	6/18	ENST00000558518.6	NP_000518.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
LDLR	ENST00000558518.6	c.895G>A	p.Ala299Thr	missense_variant	6/18	1	NM_000527.5	ENSP00000454071	P3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251388 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135880

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.0000544

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: 6.86e-7 AC: 1 AN: 1458380 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 725492

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000253

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.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Pathogenic:2 Uncertain:2

Revision: reviewed by expert panel

Submissions by phenotype

Hypercholesterolemia, familial, 1 Pathogenic:2 Uncertain:1

Uncertain significance, reviewed by expert panel	curation	ClinGen Familial Hypercholesterolemia Variant Curation Expert Panel	Feb 10, 2022	The NM_000527.5 (LDLR): c.895G>A (p.Ala299Thr) variant is classified as Uncertain significance - insufficient evidence for Familial Hypercholesterolemia by applying evidence codes (PM2, PP4, PS4_Supporting, PS3_Supporting) 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 Met: PopMAX MAF = 0.00005 in East Asian population in gnomAD (gnomAD v2.1.1). PP4 Met: This variant meets PM2 and is identified in > 1 index cases who met clinical criteria for FH after alternative causes for high cholesterol were excluded. PS4_Supporting Met: Variant meets PM2 and is identified in 2 unrelated index cases who fulfil DLCN criteria for FH (1 case from Unidad de Biof´ısica , Centro Mixto CSIC-UPV/EHU and Departamento de Bioqu´ımica, Universidad del Pa´ıs Vasco, Bilbao, Spain, PMID 21990180; 1 case from Lipid Clinic, Fundación Jiménez Díaz, Madrid, Spain, PMID 19318025). PS3_Supporting Met: Heterozygous patient lymphocytes FACS assays (level 3 functional assay) showed normal cell surface localization, but 50% LDL-LDLR uptake and binding (Etxebarria et al, Unidad de Biof´ısica, Centro Mixto CSIC-UPV/EHU and Departamento de Bioqu´ımica, Universidad del Pa´ıs Vasco, Bilbao, Spain, PMID 21990180). PP3 not met: REVEL score = 0.543, which is below the threshold of 0.75. This variant does not creating de novo acceptor or donor site and is not predicted to alter splicing. PM5 not met: There is one other variant in the same codon: LDLR: NM_000527:c.895G>T (p.Ala299Ser) is classified as Uncertain significance - insufficient evidence by these guidelines. Therefore PM5 is not met. -
Likely pathogenic, criteria provided, single submitter	research	Fundacion Hipercolesterolemia Familiar	Mar 01, 2016	- -
Likely pathogenic, criteria provided, single submitter	literature only	LDLR-LOVD, British Heart Foundation	Mar 25, 2016	- -

Familial hypercholesterolemia Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

May 30, 2021

This variant is not present in population databases (ExAC no frequency). This sequence change replaces alanine with threonine at codon 299 of the LDLR protein (p.Ala299Thr). The alanine residue is moderately conserved and there is a small physicochemical difference between alanine and threonine. This variant has been observed in individual(s) with familial hypercholesterolemia (PMID: 21990180, 19318025). ClinVar contains an entry for this variant (Variation ID: 251507). In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. Experimental studies have shown that this variant affects LDLR protein function (PMID: 21990180). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.073
BayesDel_addAF	Uncertain	0.13	D
BayesDel_noAF	Uncertain	0.12
CADD	Benign	5.3
DANN	Benign	0.74
DEOGEN2	Uncertain	0.49	T;.;.;.;.;.
Eigen	Benign	-0.85
Eigen_PC	Benign	-0.77
FATHMM_MKL	Benign	0.29	N
LIST_S2	Benign	0.65	T;T;T;T;T;T
M_CAP	Pathogenic	0.34	D
MetaRNN	Benign	0.39	T;T;T;T;T;T
MetaSVM	Uncertain	-0.27	T
MutationAssessor	Benign	-0.10	N;.;.;.;.;N
MutationTaster	Benign	1.0	N;N;N;N;N;N;N
PrimateAI	Benign	0.25	T
PROVEAN	Benign	-0.65	N;N;N;N;N;N
REVEL	Uncertain	0.54
Sift	Benign	0.40	T;T;T;T;T;T
Sift4G	Benign	0.57	T;T;T;T;T;T
Polyphen		0.034	B;.;.;.;.;.
Vest4		0.22
MutPred		0.52		Gain of disorder (P = 0.0438);Gain of disorder (P = 0.0438);.;.;.;Gain of disorder (P = 0.0438);
MVP		1.0
MPC		0.21
ClinPred		0.54	D
GERP RS		4.3
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.15
gMVP		0.76

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: rs879254711; hg19: chr19-11218145;