chr19-11102662-A-G

Variant names:

• chr19-11102662-A-G
• rs544203837
• NM_000527.5:c.191-2A>G

Variant summary

Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PVS1_Moderate PM2 PP5_Very_Strong

The NM_000527.5(LDLR):​c.191-2A>G variant causes a splice acceptor, intron change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000186 in 1,613,236 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★).

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 31)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: LDLR NM_000527.5 splice_acceptor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:9
• Conservation: PhyloP100: 8.68
• Publications: 4 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]

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

ACMG classification

Our verdict: Pathogenic. The variant received 12 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.04761905 fraction of the gene. Cryptic splice site detected, with MaxEntScore 5.3, offset of -45, new splice context is: gccactgtgctcggcctcAGtgg. Cryptic site results in inframe change. If cryptic site found is not functional and variant results in exon loss, it results in inframe change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 19-11102662-A-G is Pathogenic according to our data. Variant chr19-11102662-A-G is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 226306.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.191-2A>G		splice_acceptor_variant, intron_variant	Intron 2 of 17	ENST00000558518.6	NP_000518.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
LDLR	ENST00000558518.6	c.191-2A>G		splice_acceptor_variant, intron_variant	Intron 2 of 17	1	NM_000527.5	ENSP00000454071.1

Frequencies

GnomAD3 genomes AF: 0.00000658 AC: 1 AN: 152024 Hom.: 0 Cov.: 31

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: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00316

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461094 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 726852

African (AFR) AF: 0.00 AC: 0 AN: 33454

American (AMR) AF: 0.00 AC: 0 AN: 44690

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26106

East Asian (EAS) AF: 0.00 AC: 0 AN: 39656

South Asian (SAS) AF: 0.00 AC: 0 AN: 86252

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53356

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5764

European-Non Finnish (NFE) AF: 0.00000180 AC: 2 AN: 1111488

Other (OTH) AF: 0.00 AC: 0 AN: 60328

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152142 Hom.: 0 Cov.: 31 AF XY: 0.0000134 AC XY: 1 AN XY: 74366

African (AFR) AF: 0.00 AC: 0 AN: 41528

American (AMR) AF: 0.00 AC: 0 AN: 15260

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3468

East Asian (EAS) AF: 0.00 AC: 0 AN: 5166

South Asian (SAS) AF: 0.00 AC: 0 AN: 4822

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10592

Middle Eastern (MID) AF: 0.00340 AC: 1 AN: 294

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 67990

Other (OTH) AF: 0.00 AC: 0 AN: 2110

Alfa AF: 0.00 Hom.: 0

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:9

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hypercholesterolemia, familial, 1 Pathogenic:6

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

Diagnostic Laboratory, Department of Genetics, University Medical Center Groningen

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

Mar 22, 2012

Cardiovascular Genetics Laboratory, PathWest Laboratory Medicine WA - Fiona Stanley Hospital

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

Mar 01, 2016

Fundacion Hipercolesterolemia Familiar

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: research

Robarts Research Institute, Western University

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

not provided Pathogenic:1

Clinical Genetics, Academic Medical Center

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

Cardiovascular phenotype Pathogenic:1

Feb 09, 2022

Ambry Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.191-2A>G intronic pathogenic mutation results from an A to G substitution two nucleotides upstream from coding exon 3 in the LDLR gene. Alterations that disrupt the canonical splice site are expected to result in aberrant splicing. In silico splice site analysis predicts that this alteration will weaken the native splice acceptor site and will result in the creation or strengthening of a novel splice acceptor site. The resulting transcript is predicted to be in-frame and is not expected to trigger nonsense-mediated mRNA decay; however, direct evidence is unavailable. The exact functional effect of the altered amino acid sequence is unknown; however, the impacted region is critical for protein function (Ambry internal data). This mutation has been reported in several familial hypercholesterolemia (FH) cohorts (Day IN et al. Hum Mutat, 1997;10:116-27; Lombardi MP et al. Clin Genet, 2000 Feb;57:116-24; Wang J et al. Arterioscler Thromb Vasc Biol, 2016 12;36:2439-2445; Dron JS et al. BMC Med Genomics, 2020 02;13:23; Sturm AC et al. JAMA Cardiol, 2021 08;6:902-909). Additionally, a functional study showed the expression of an alternate transcript (Holla ØL et al. Mol Genet Metab, 2009 Apr;96:245-52). This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). Based on the supporting evidence, this alteration is interpreted as a disease-causing mutation.

Familial hypercholesterolemia Pathogenic:1

May 01, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

For these reasons, this variant has been classified as Pathogenic. Studies have shown that disruption of this splice site results in skipping of exon 3, but is expected to preserve the integrity of the reading-frame (PMID: 19208450). ClinVar contains an entry for this variant (Variation ID: 226306). This variant is also known as In 2 A-2G and IVS2-2A>G. Disruption of this splice site has been observed in individuals with familial hypercholesterolemia (PMID: 9259195, 10735632, 21475731, 22390909, 27765764; Invitae). This variant is not present in population databases (gnomAD no frequency). This sequence change affects an acceptor splice site in intron 2 of the LDLR gene. RNA analysis indicates that disruption of this splice site induces altered splicing and likely results in a shortened protein product.

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Uncertain	-0.070
CADD	Pathogenic	34
DANN	Uncertain	0.98
DEOGEN2	Benign	0.0	.;.;.;.;.
Eigen	Pathogenic	0.91
Eigen_PC	Pathogenic	0.69
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Benign	0.0	.;.;.;.;.
MetaRNN	Benign	0.0	.;.;.;.;.
MutationAssessor	Benign	0.0	.;.;.;.;.
PhyloP100		8.7
PROVEAN	Benign	0.0	.;.;.;.;.
REVEL	Benign	0.0
Sift	Pathogenic	0.0	.;.;.;.;.
Sift4G	Pathogenic	0.0	.;.;.;.;.
Vest4		0.0
GERP RS		5.6
Mutation Taster		=0/100	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.92
SpliceAI score (max)		1.0		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.83		Position offset: 33
DS_AL_spliceai		1.0		Position offset: 2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs544203837; hg19: chr19-11213338;