Ignite Creation Date:
2024-05-06 @ 1:17 PM
Last Modification Date:
2024-10-26 @ 1:12 PM
Study NCT ID:
NCT03984149
Status:
UNKNOWN
Last Update Posted:
2022-07-29
First Post:
2019-05-21
Brief Title:
Lipa Gene Mutation in PED-LIPIGEN Pediatric FH Subjects
Sponsor:
Fondazione SISA Societa Italiana per lo Studio della Arteriosclerosi
Organization:
Fondazione SISA Societa Italiana per lo Studio della Arteriosclerosi
Study Overview
Official Title:
Prevalence and Mutation Rate of Lipa Gene in LIPIGEN Subjects With Clinical Diagnosis of FH
Status:
UNKNOWN
Status Verified Date:
2022-07
Last Known Status:
RECRUITING
Delayed Posting:
No
If Stopped, Why?:
Not Stopped
Has Expanded Access:
False
If Expanded Access, NCT#:
N/A
Has Expanded Access, NCT# Status:
N/A
Acronym:
None
Brief Summary:
Familial Hypercholesterolemia FH is a monogenic autosomal dominant disease also known as Autosomal Dominant Hypercholesterolemia - ADH that leads to dramatically increased levels of Low Density Lipoprotein LDL and total cholesterol associated to tendon xanthomas xanthelasma corneal arcus premature atherosclerosis and to an increased risk of coronary artery disease CAD and myocardial infarction
FH is mainly caused by mutations in genes encoding for proteins affecting hepatic LDL cholesterol uptake including the LDL receptor LDLR gene or the gene encoding the only apolipoprotein of LDL the apolipoprotein B APOB or the gene encoding a protease regulating LDLR levels on the cell membrane Lysosomal Acid Lipase A LIPA gene encode for Lysosomal acid lipase LAL enzyme responsible for hydrolyzing cholesterol esters and triglycerides that are delivered to lysosomes Mutations in LIPA that completely inactivate LAL are the molecular cause of Wolman disease a rapidly lethal disease of infancy while mutations in LIPA that result in residual enzymatic activity of LAL are responsible of a disorder characterized by a less severe phenotype known as cholesterol ester storage disease CESD Patients with CESD usually show a phenotype characterized by hepatic disease and mixed hyperlipidemia with elevated levels of LDL-C and triglycerides TG and decreased HDL-C levels
A broader phenotypic presentation for loss of function mutations in LIPA suggests that LIPA mutations may be considered in patients with apparently monogenic FH in whom mutations in the known candidate genes are not detectable
The project is aimed to evaluate the prevalence and the mutation rate of LIPA gene in subjects with a clinical diagnosis of FH and already genetically characterized in whom pathogenic mutations in the known candidate genes have not been identified The analysis will be performed in about 250 FH pediatric subjects and putative causal mutations will be also tested for co-segregation in available families in affected and unaffected members
FH is mainly caused by mutations in genes encoding for proteins affecting hepatic LDL cholesterol uptake including the LDL receptor LDLR gene or the gene encoding the only apolipoprotein of LDL the apolipoprotein B APOB or the gene encoding a protease regulating LDLR levels on the cell membrane Lysosomal Acid Lipase A LIPA gene encode for Lysosomal acid lipase LAL enzyme responsible for hydrolyzing cholesterol esters and triglycerides that are delivered to lysosomes Mutations in LIPA that completely inactivate LAL are the molecular cause of Wolman disease a rapidly lethal disease of infancy while mutations in LIPA that result in residual enzymatic activity of LAL are responsible of a disorder characterized by a less severe phenotype known as cholesterol ester storage disease CESD Patients with CESD usually show a phenotype characterized by hepatic disease and mixed hyperlipidemia with elevated levels of LDL-C and triglycerides TG and decreased HDL-C levels
A broader phenotypic presentation for loss of function mutations in LIPA suggests that LIPA mutations may be considered in patients with apparently monogenic FH in whom mutations in the known candidate genes are not detectable
The project is aimed to evaluate the prevalence and the mutation rate of LIPA gene in subjects with a clinical diagnosis of FH and already genetically characterized in whom pathogenic mutations in the known candidate genes have not been identified The analysis will be performed in about 250 FH pediatric subjects and putative causal mutations will be also tested for co-segregation in available families in affected and unaffected members
Detailed Description:
Lysosomal acid lipase LAL is encoded by LIPA gene located on chromosome 10q233-q23 and consists of 10 exons LIPA mRNA messenger RiboNucleic Acid GenBank accession number NM_000235 is 2782 bp long and encodes a mature protein of 375 residues GenBank accession number NP_000226 The sequencing of all 10 exons of LIPA gene will consist of 10 PCR Polymerase Chain Reaction amplification reactions for the 10 exons and the proximal promoter followed by 20 sequence reactions forward and reverse sequencing with appropriate primers designed to include the intron-exon boundaries This analysis will be performed in about 250 FH pediatric subjects as specified in project description
The sequencing work will be performed taking advantage of 2 automated 8 capillaries automated DNA Sequencer 3500 Genetic Analyzer Thermo Fisher Scientific Monza Italy currently available in the laboratory of the Units involved in the project
In case of identification of unreported sequence variants the presence of these mutations will be assessed in a sample of at least 100 normolipidemic subjects of the population in order to define whether the nucleotide changes are rare sequence variations with a putative functional effect or represent common polymorphisms In case of finding of rare variants in the coding regions an in silico analysis will be performed by using two different softwares Polyphen httpgeneticsbwhharvardedupph and Panther httpwwwpantherdborg to predict the putative damaging role of the mutations on the protein In case of intronic variants the specifically designed software Automated Splice Site Analysis will be applied httpswwwspliceuwoca
Putative causal mutations will be also tested for co-segregation in available families in affected and unaffected members
In order to test the effect of variants on enzyme activity LAL-activity will be assayed with dried blood spot DBS technique using the inhibitors Lalistat 2 in carriers and non carriers of these mutations belonging to available kindred
The sequencing work will be performed taking advantage of 2 automated 8 capillaries automated DNA Sequencer 3500 Genetic Analyzer Thermo Fisher Scientific Monza Italy currently available in the laboratory of the Units involved in the project
In case of identification of unreported sequence variants the presence of these mutations will be assessed in a sample of at least 100 normolipidemic subjects of the population in order to define whether the nucleotide changes are rare sequence variations with a putative functional effect or represent common polymorphisms In case of finding of rare variants in the coding regions an in silico analysis will be performed by using two different softwares Polyphen httpgeneticsbwhharvardedupph and Panther httpwwwpantherdborg to predict the putative damaging role of the mutations on the protein In case of intronic variants the specifically designed software Automated Splice Site Analysis will be applied httpswwwspliceuwoca
Putative causal mutations will be also tested for co-segregation in available families in affected and unaffected members
In order to test the effect of variants on enzyme activity LAL-activity will be assayed with dried blood spot DBS technique using the inhibitors Lalistat 2 in carriers and non carriers of these mutations belonging to available kindred
Study Oversight
Has Oversight DMC:
None
Is a FDA Regulated Drug?:
False
Is a FDA Regulated Device?:
False
Is an Unapproved Device?:
None
Is a PPSD?:
None
Is a US Export?:
None
Is an FDA AA801 Violation?:
None