rs1131692222

Variant names:

• chr19-11123260-A-ACCCGAC
• rs1131692222
• NM_000527.5:c.2229_2234dupCCGACC

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PM2 PM4 PP5

The NM_000527.5(LDLR):​c.2229_2234dupCCGACC​(p.Pro745_Val746insArgPro) variant causes a disruptive inframe insertion change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency: Genomes: not found (cov: 30)
• Consequence: LDLR NM_000527.5 disruptive_inframe_insertion
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:2
• Conservation: PhyloP100: -0.486
• Publications: 0 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: Uncertain_significance. The variant received 5 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM4: Nonframeshift variant in NON repetitive region in NM_000527.5.
• PP5: Variant 19-11123260-A-ACCCGAC is Pathogenic according to our data. Variant chr19-11123260-A-ACCCGAC is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 430796.We mark this variant Likely_pathogenic, oryginal submission is: [Conflicting_classifications_of_pathogenicity].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
LDLR	NM_000527.5	c.2229_2234dupCCGACC	p.Pro745_Val746insArgPro	disruptive_inframe_insertion	Exon 15 of 18	ENST00000558518.6	NP_000518.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
LDLR	ENST00000558518.6	c.2229_2234dupCCGACC	p.Pro745_Val746insArgPro	disruptive_inframe_insertion	Exon 15 of 18	1	NM_000527.5	ENSP00000454071.1

Frequencies

GnomAD3 genomes Cov.: 30

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 30

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:2

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Hypercholesterolemia, familial, 1 Pathogenic:1 Uncertain:1

Mar 30, 2017

U4M - Lille University & CHRU Lille, Université de Lille - CHRU de Lille

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Feb 05, 2024

All of Us Research Program, National Institutes of Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant causes an in-frame duplication of two amino acids of the O-linked oligo-saccharide domain in the LDLR protein. To our knowledge, functional studies have not been reported for this variant. This variant has been reported in at least two individuals affected with familial hypercholesterolemia (PMID: 26802169). This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -

not specified Uncertain:1

Apr 26, 2022

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: LDLR c.2229_2234dupCCGACC (p.Arg744_Pro745dup) results in an in-frame duplication that is predicted to duplicate two amino acids into the encoded protein. The variant was absent in 251278 control chromosomes. c.2229_2234dupCCGACC has been reported in the literature in a mother and her daughter with definite Autosomal Dominant Hypercholesterolemia and in a second family with possible Autosomal Dominant Hypercholesterolemia (Wintjens_2016). These data indicate that the variant may be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. One clinical diagnostic laboratory has submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. One laboratory classified the variant as likely pathogenic. Based on the evidence outlined above, the variant was classified as VUS-possibly pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
PhyloP100		-0.49
Mutation Taster		=43/57	disease causing (ClinVar)

Splicing

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

Other links and lift over

dbSNP: rs1131692222; hg19: chr19-11233936;