- Email: [email protected]
Applicability of the low-density lipoprotein cholesterol gene score in a South European population
Abstracts / Atherosclerosis 263 (2017) e29ee110
Inherited dyslipidemias III SAG193. IDENTIFICATION OF A NOVEL LMF1 NONSENSE MUTATION RESPONSIBLE FOR SEVERE HYPERTRIGLYCERIDEMIA BY TARGETED NEXT-GENERATION SEQUENCING Rossella Spina, Angelo B. Cefalu', Davide Noto, Valeria Ingrassia, Antonina Giammanco, Francesca Fayer, Gabriella Misiano, Chiara Scrimali, Grazia I. Altieri, Antonina Ganci, Carlo M. Barbagallo, Maurizio Averna. University of Palermo, Palermo, Italy Aim: Severe hypertriglyceridemia (HTG) may result from mutations in genes affecting the intravascular lipolysis of triglyceride rich lipoproteins. The aim of this study was to investigate monogenic causes of severe HTG. Methods: We used a targeted Next Generation Sequencing (NGS) approach to capture the coding exons and intron/exon boundaries of 18 genes affecting the main pathways of triglyceride synthesis and metabolism. Results: The targeted resequencing of candidate genes of severe HTG led to the discovery of a novel homozygous nonsense mutation in one patient with severe hypertriglyceridemia. The mutation causes a C>G substitution in exon 9 (c.1380C>G), leading to a premature stop codon (W460X). The clinical and molecular familial cascade screening allowed the identification of two additional affected siblings and seven heterozygous carriers of the mutation. Homozygosity for the c.1380C>G mutation resulted in a severe HTG phenotype in the proband (II-2) while two other siblings (II-1 and II-4) showed mild to moderate HTG suggesting a different and variable pattern of penetrance among carriers of the same mutation of the LMF1 gene. None of them have suffered of acute pancreatitis or recurrent abdominal pain. Conclusions: We describe the third novel nonsense mutation of LMF1 gene (c.1380C>G -p.Y460X) identified by a customized NGS panel for targeted gene sequencing of 18 genes involved in hypertriglyceridemia. More studies are needed to understand the reasons of the phenotypic variability of the same molecular defect in the same family.
SAG194. MUTATIONAL ANALYSIS OF CHILDREN AND ADOLESCENTS WITH FAMILIAL HYPERCHOLESTEROLEMIA ASCERTAINED BY CHILD-PARENT SCREENING Ilenia Minicocci1, Simone Pozzessere1, Cristina Prisco1, Anna Alessia Di Costanzo1, Eliana Martino2, Francesco Montali1, Martino2, Marcello Arca1. 1 Departments of Internal Medicine and Allied Sciences, Sapienza, University of Rome, Rome, Italy; 2 Departments of Pediatrics, Sapienza, University of Rome, Rome, Italy Aim: The diagnosis of familial hypercholesterolemia (FH) in childhood is not straightforward. The European Atherosclerosis Society (EAS) proposed diagnostic criteria based on child-parent assessment, but their effectiveness in predicting FH-causative mutations in unselected hypercholesterolemic children has not been extensively evaluated. Methods: LDLR, APOB and PCSK9 genes were sequenced in 78 children and adolescent (mean age 8.4 ± 3.7 years) with clinically diagnosed FH. The presence of polygenic hypercholesterolemia was further searched by genotyping 6 low-density lipoprotein cholesterol (LDL-C)-raising singlenucleotide polymorphisms (SNPs). Results: Thirty-nine children (50.0%) were found to carrying LDLR, but none APOB or PCSK9 mutant alleles. Overall, 27 different LDLR mutations were identified and two were novel. Children carrying mutations showed higher LDL-C (215.2 ± 52.7 mg/dl vs. 181.0 ± 44.6 mg/dl, P<0.001) and apolipoprotein B (ApoB) levels (131.6 ± 38.3 mg/dl vs. 100.3 ± 30.0 mg/dl, P<0.004), as compared to non-carriers. A LDL-C of ~190 mg/dl was the optimal value to discriminate children with and without LDLR mutations. When different diagnostic criteria were compared, those proposed by EAS showed a reasonable balance between sensitivity and specificity in the identification of LDLR mutations. In children without mutation, the FH phenotype was not caused by the aggregation of LDL-C raising SNPs.
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Conclusions: In unselected hypercholesterolemic children, LDL-C levels >190 mg/dl and a positive family history of hypercholesterolemia appeared to be most reliable criteria for detecting FH. As 50% of suspected FH children did not carry FH-causing mutations, our results underlined the importance of genetic testing for FH during childhood.
SAG195. ELEVATED LIPOPROTEIN(A) AND FAMILIAL HYPERCHOLESTEROLAEMIA PHENOTYPES IN PATIENTS ADMITTED TO A CORONARY CARE UNIT WITH CORONARY ARTERY DISEASE Katrina Ellis1, Jing Pang1, Damon Bell1, 2, John Burnett1, 2, 3, Carl Schultz1, 2, Graham Hillis1, 2, Gerald Watts1, 2. 1 University of Western Australia- School of Medicine and Pharmacology, Perth, Australia; 2 Royal Perth Hospital- Department of Cardiology, Perth, Australia; 3 Royal Perth Hospital and Fiona Stanley Hospital Network- PathWest Laboratory Medicine, Perth, Australia Aim: Elevated lipoprotein(a) [Lp(a)] and familial hypercholesterolaemia (FH) are not routinely screened for in patients presenting to the coronary care unit (CCU). We audited the frequency of these disorders in patients admitted to the CCU at Royal Perth Hospital. Methods: Plasma Lp(a) levels were measured in all CCU patients admitted between the 25th of January and 11th of August 2016. Elevated Lp(a) was defined as levels >¼50mg/dL. Patients with LDL-cholesterol >¼5.0mmol/L were deemed to exhibit phenotypic FH. Premature CAD was diagnosed in patients <60 yrs. Regression analyses adjusted for established CAD risk factors. Results: During a 6.5 month audit, 345 patients were screened for elevated Lp(a) and phenotypic FH; 69.6% were male and the average age was 61.8 years. A total of 169 patients (49%) had premature CAD. Elevated Lp(a) was present in a greater proportion of premature CAD patients (32% versus 22%) and conferred a 1.8-fold increase in CAD risk when compared with those without premature CAD (P<¼0.04). Similarly, an FH phenotype was significantly more common in individuals with premature CAD (20.2% versus 10.8%), and was associated with a 3.1-fold increased risk of a premature event (P<¼0.02). Twice as many patients with premature CAD met the criteria for both elevated Lp(a) and phenotypic FH (10.7% vs 5.1%; P¼0.05) compared with non-premature CAD patients. The combination of elevated Lp(a) and FH conferred a 4-fold increased risk of premature CAD (P¼0.004). Conclusions: Elevated Lp(a) and phenotypic FH were commonly encountered in patients admitted to the CCU and were more frequent among those with premature CAD.
SAG196. APPLICABILITY OF THE LOW-DENSITY LIPOPROTEIN CHOLESTEROL GENE SCORE IN A SOUTH EUROPEAN POPULATION Cibelle Mariano1, 2, Marta Futema3, Steve E. Humphries3, Mafalda Bourbon1, 2. 1 Instituto Nacional de Saúde Doutor Ricardo Jorge - DPS, Lisboa, Portugal; 2 Biosystems & Integrative Sciences Institute (BioISI), Faculdade de Ci^ encias, Universidade de Lisboa, Lisboa, Portugal; 3 Institute of Cardiovascular Science - Centre for Cardiovascular Genetics, University College London, London, United Kingdom Aim: Previous studies have demonstrated that the co-inheritance of LDLC-raising alleles from 6 SNPs is associated with the Familial Hypercholesterolaemia (FH) phenotype. Here we investigate the applicability of the LDL-C genetic risk score in the Portuguese FH population. Methods: Overall, 1320 DNA samples from a population study (eCOR) and 254 from the Portuguese FH study (103 mutation positive (FH+), 151 mutation negative (FH-)) were genotyped for the 6 LDL-C genetic risk score SNPs. The LDL-C weighted score was calculated as previously described. The eCOR cohort was used to determine the score values for the healthy Portuguese population. Polygenic hypercholesterolaemia was defined as a score above the top quartile. Results: FH- (0.68±0.21) and FH+ (0.72±0.19) patients had significantly higher score values than eCOR (0.62±0.22) (P<<0.001), a large proportion being in the top quartile (FH-:38%, FH+:31%). FH- patients had higher score
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Abstracts / Atherosclerosis 263 (2017) e29ee110
values than FH+, although not significantly (P¼0.09). Also, less FH- patients were in the bottom quartile than FH+ (11% vs 20%, P¼0.035). Comparison of the UK control “Whitehall” sample and eCOR mean score values showed no significant differences (0.632±0.22 vs 0.62±0.22). Conclusions: The LDL-C genetic risk score was validated in the Portuguese population, and revealed that almost half of the FH- patients could have polygenic hypercholesterolaemia, while a small part might have unknown variants in a FH associated gene or in a new gene and should be investigated by exome sequencing.
SAG197. NATURAL HISTORY AND GENE EXPRESSION SIGNATURE OF PLATELET COUNT IN LIPOPROTEIN LIPASE DEFICIENCY e de Montr eal Karine Tremblay, Diane Brisson, Daniel Gaudet. Universit Community Genomic Medicine Centre and ECOGENE-21, Saguenay, Canada Aim: Platelet physiology is affected by the post-prandial status. Lipoprotein lipase deficiency (LPLD) is a rare post-prandial disease associated with severe hypertriglyceridemia, chylomicronemia and increased risk of pancreatitis and metabolic complications. Important fluctuations of the platelet count (PLT) in LPLD have been reported. The aim of this study is to describe the natural history and gene expression signature of PLT in LPLD. Methods: The historical PLT values of 42 LPLD adults have been reviewed. The gene expression profile of subjects with history of low (PLT <130 x 103m/L) vs normal PLT was compared using whole blood RNA samples hybridized on Affymetrix Human Gene 2.0 ST Array. Results: Over a 15 years period, 24/42 (57.1%) of LPLD patients presented PLT <130 x 103m/L at least once. Thrombocytopenia was severe (PLT <50 x 103m/L) in 4.8% of cases. No bleeding, petechia or bruising were noticed. Conversely, 14.3% of cases presented thrombocytosis (PLT >450 x103m/L) at least once. The gene expression profile of ten of these LPLD patients identified ten down-regulated (MMP9, CEACAM8, SRGAP2-AS1, SLC38A5, KCNJ15, DEFA3, LTF, RNF144B, CTSE, MMP8) and three up-regulated (MIR374A, SCARNA15 and MIR4774) annotated probes in low PLT group (n¼5) compared to normal PLT group (n¼5) (p-values <0.01; jfold changej >2). Conclusions: These results illustrate that LPLD is associated with important asymptomatic fluctuations of the PLT over time. The gene expression signature of low PLT in LPLD may contribute to understand the effect of post-prandial metabolism on platelets physiology. Fasting and postprandial analyses of platelet structure and functions in LPLD are ongoing.
SAG198. FATTY ACID-BINDING PROTEIN 5 AS A RESIDUAL RISK FOR ATHEROSCLEROTIC CARDIOVASCULAR DISEASE IN PATIENTS WITH FAMILIAL HYPERCHOLESTEROLEMIA Masatsune Ogura1, Masato Furuhashi2, Megumu Morimoto1, Megumi Matsumoto2, Tetsuji Miura2, Mariko Harada-Shiba1. 1 National Cerebral and Cardiovascular Center Research Institute, Suita, Japan; 2 Sapporo Medical University School of Medicine, Sapporo, Japan Aim: Aim: Fatty acid-binding protein (FABP) 4 and FABP5 play important roles in the development of atherosclerosis and that their impacts differentially involve macrophages. We hypothesized FABPs may partly explain residual atherosclerotic cardiovascular disease (ASCVD) risk in statintreated familial hypercholesterolemia (FH) patients. We investigated associations of plasma FABP4 and FABP5 levels with the presence of ASCVD and clinical features in these patients. Methods: Methods: Two hundred and nineteen heterozygous FH patients treated with statin were enrolled in this cross-sectional study. Plasma FABPs levels were measured using enzyme-linked immunosorbent assay kits. Additionally, we assessed Achilles tendon thickness and carotid intima-media thickness. Results: Results: Eighty-five patients (38.8%) were known to have ASCVD. In univariate analyses, both plasma FABP4 and FABP5 levels were higher in patients with ASCVD compared with those without ASCVD. However, only
increased FABP5 level was associated with the presence of ASCVD after adjustment for traditional risk factors (OR per 1-SD increase, 1.27; 95% CI, 1.03e1.57; P¼0.0233). Additionally, increased FABP5 level was also related to increased maximum carotid intima-media thickness (IMT) as well. Although these FABPs levels were related to mean carotid IMT as well as Achilles tendon thickness in univariate analyses, these correlations were attenuated after multiple linear regression analyses. Conclusions: Conclusions: Plasma FABP5 level was independently associated with the presence of ASCVD and asymptomatic atherosclerosis in heterozygous FH. In view of residual risks after treatment with statins, FABP5 might be a novel biomarker and a therapeutic target for preventing atherosclerosis in patients with FH.
SAG199. CARDIOVASCULAR RISK IN CHILDREN: THE CLINICAL RELEVANCE OF EARLY AND TIMELY STRATIFICATION ^s Gomes1, Catarina Branda ~o1, Mafalda Bourbon2, Fa tima Pinto1. 1 Centro Ine Hospitalar Lisboa Central, Lisbon, Portugal; 2 Instituto Nacional de Saúde, Lisbon, Portugal Aim: The increasing prevalence of cardiovascular risk factors in children needs a structured approach with early identification and treatment. We aimed at characterizing the methodology and the results in a Paediatric Cardiology centre with a specialized outpatient clinic in this field. Methods: Retrospective study was performed from chart review, and classic risk factors, anthropometry, and insulin-resistance index (HOMAIR) were analysed. Every patient is evaluated clinically. ECG, ecochardiogram and peripheral arterial tonometry (PAT) are routinelly obtained. Results: We studied 301 patients, 60% females, mean age 13.9 years (range 6-19) and mean BMI 29.7 (50 patients had BMI > 30). In the studied population, 2 or more classical cardiovascular risk factors were prevalent in 42% of patients. The lipid mean values were: total cholesterol (TC): 171,4±38,4 mg/dL; HDLc: 49,2 ± 15,9 mg/dL; LDLc 109,6±35,6 mg/dL and triglycerides: 93,5±62,1 mg/dL. Of these, 32 patients had high TC ( mean 233 mg/dL), with high atherogenicity index in 11. Heterozygotic Familial Hypercholesterolemia (FH) was confirmed in 6 patients, with various pathogenic mutations of LDLR gene. AMBP performed in 73 patients showed high blood pressure in 58 with 19 patients exclusively non-dipper. We found endothelial dysfunction in 38 patients with renal failure and dyslipidemia. Conclusions: A structured evaluation of cardiovascular risk factors in pediatric age in a selected population combining several indexes, TAP and AMBP was accurate to evaluate and follow these patients. This methodology also allowed selective testing for FH, allowing identification of 4 cases of heterozygotic FH in 2 families.
SAG200. MOLECULAR ANALYSIS OF 15 HOMOZYGOUS LAL-D PATIENTS FROM GREECE USING DBS SCREENING Elena Kamenet1, Vasiliki Mollaki2, John Hamilton3, Ekaterina Zakharova1, Euridiki Drogari2. 1 FSBI, Research Centre for Medical Genetics, Moscow, Russia; 2 Metabolic Unit, 1st Department of Pediatrics, National and Kapodistrian University of Athens, Athens, Greece; 3 Biochemistry Department, NHS Greater Glasgow & Clyde, Glasgow, United Kingdom Aim: Lysosomal acid lipase (LAL), encoded by the LIPA gene, catalyzes hydrolysis of cholesteryl esters and triglycerides. Mild splicing-junction mutation c.894G>A is considered as the most frequent mutation (about 60% of all defects in European populations). The aim of this study was to define the spectrum of LIPA mutations in Greek population. Methods: In 15 patients (6 male and 9 female, age from 4 to 27 years) from 13 unrelated Greek families LAL activity was determined using DBS by fluorometric analysis. In all these patients, their 26 parents and their 8 healthy siblings molecular analysis of LIPA gene was carried out. Coding sequence of LIPA was analyzed by direct sequencing (ABI3500).
Inherited dyslipidemias III SAG193. IDENTIFICATION OF A NOVEL LMF1 NONSENSE MUTATION RESPONSIBLE FOR SEVERE HYPERTRIGLYCERIDEMIA BY TARGETED NEXT-GENERATION SEQUENCING Rossella Spina, Angelo B. Cefalu', Davide Noto, Valeria Ingrassia, Antonina Giammanco, Francesca Fayer, Gabriella Misiano, Chiara Scrimali, Grazia I. Altieri, Antonina Ganci, Carlo M. Barbagallo, Maurizio Averna. University of Palermo, Palermo, Italy Aim: Severe hypertriglyceridemia (HTG) may result from mutations in genes affecting the intravascular lipolysis of triglyceride rich lipoproteins. The aim of this study was to investigate monogenic causes of severe HTG. Methods: We used a targeted Next Generation Sequencing (NGS) approach to capture the coding exons and intron/exon boundaries of 18 genes affecting the main pathways of triglyceride synthesis and metabolism. Results: The targeted resequencing of candidate genes of severe HTG led to the discovery of a novel homozygous nonsense mutation in one patient with severe hypertriglyceridemia. The mutation causes a C>G substitution in exon 9 (c.1380C>G), leading to a premature stop codon (W460X). The clinical and molecular familial cascade screening allowed the identification of two additional affected siblings and seven heterozygous carriers of the mutation. Homozygosity for the c.1380C>G mutation resulted in a severe HTG phenotype in the proband (II-2) while two other siblings (II-1 and II-4) showed mild to moderate HTG suggesting a different and variable pattern of penetrance among carriers of the same mutation of the LMF1 gene. None of them have suffered of acute pancreatitis or recurrent abdominal pain. Conclusions: We describe the third novel nonsense mutation of LMF1 gene (c.1380C>G -p.Y460X) identified by a customized NGS panel for targeted gene sequencing of 18 genes involved in hypertriglyceridemia. More studies are needed to understand the reasons of the phenotypic variability of the same molecular defect in the same family.
SAG194. MUTATIONAL ANALYSIS OF CHILDREN AND ADOLESCENTS WITH FAMILIAL HYPERCHOLESTEROLEMIA ASCERTAINED BY CHILD-PARENT SCREENING Ilenia Minicocci1, Simone Pozzessere1, Cristina Prisco1, Anna Alessia Di Costanzo1, Eliana Martino2, Francesco Montali1, Martino2, Marcello Arca1. 1 Departments of Internal Medicine and Allied Sciences, Sapienza, University of Rome, Rome, Italy; 2 Departments of Pediatrics, Sapienza, University of Rome, Rome, Italy Aim: The diagnosis of familial hypercholesterolemia (FH) in childhood is not straightforward. The European Atherosclerosis Society (EAS) proposed diagnostic criteria based on child-parent assessment, but their effectiveness in predicting FH-causative mutations in unselected hypercholesterolemic children has not been extensively evaluated. Methods: LDLR, APOB and PCSK9 genes were sequenced in 78 children and adolescent (mean age 8.4 ± 3.7 years) with clinically diagnosed FH. The presence of polygenic hypercholesterolemia was further searched by genotyping 6 low-density lipoprotein cholesterol (LDL-C)-raising singlenucleotide polymorphisms (SNPs). Results: Thirty-nine children (50.0%) were found to carrying LDLR, but none APOB or PCSK9 mutant alleles. Overall, 27 different LDLR mutations were identified and two were novel. Children carrying mutations showed higher LDL-C (215.2 ± 52.7 mg/dl vs. 181.0 ± 44.6 mg/dl, P<0.001) and apolipoprotein B (ApoB) levels (131.6 ± 38.3 mg/dl vs. 100.3 ± 30.0 mg/dl, P<0.004), as compared to non-carriers. A LDL-C of ~190 mg/dl was the optimal value to discriminate children with and without LDLR mutations. When different diagnostic criteria were compared, those proposed by EAS showed a reasonable balance between sensitivity and specificity in the identification of LDLR mutations. In children without mutation, the FH phenotype was not caused by the aggregation of LDL-C raising SNPs.
e99
Conclusions: In unselected hypercholesterolemic children, LDL-C levels >190 mg/dl and a positive family history of hypercholesterolemia appeared to be most reliable criteria for detecting FH. As 50% of suspected FH children did not carry FH-causing mutations, our results underlined the importance of genetic testing for FH during childhood.
SAG195. ELEVATED LIPOPROTEIN(A) AND FAMILIAL HYPERCHOLESTEROLAEMIA PHENOTYPES IN PATIENTS ADMITTED TO A CORONARY CARE UNIT WITH CORONARY ARTERY DISEASE Katrina Ellis1, Jing Pang1, Damon Bell1, 2, John Burnett1, 2, 3, Carl Schultz1, 2, Graham Hillis1, 2, Gerald Watts1, 2. 1 University of Western Australia- School of Medicine and Pharmacology, Perth, Australia; 2 Royal Perth Hospital- Department of Cardiology, Perth, Australia; 3 Royal Perth Hospital and Fiona Stanley Hospital Network- PathWest Laboratory Medicine, Perth, Australia Aim: Elevated lipoprotein(a) [Lp(a)] and familial hypercholesterolaemia (FH) are not routinely screened for in patients presenting to the coronary care unit (CCU). We audited the frequency of these disorders in patients admitted to the CCU at Royal Perth Hospital. Methods: Plasma Lp(a) levels were measured in all CCU patients admitted between the 25th of January and 11th of August 2016. Elevated Lp(a) was defined as levels >¼50mg/dL. Patients with LDL-cholesterol >¼5.0mmol/L were deemed to exhibit phenotypic FH. Premature CAD was diagnosed in patients <60 yrs. Regression analyses adjusted for established CAD risk factors. Results: During a 6.5 month audit, 345 patients were screened for elevated Lp(a) and phenotypic FH; 69.6% were male and the average age was 61.8 years. A total of 169 patients (49%) had premature CAD. Elevated Lp(a) was present in a greater proportion of premature CAD patients (32% versus 22%) and conferred a 1.8-fold increase in CAD risk when compared with those without premature CAD (P<¼0.04). Similarly, an FH phenotype was significantly more common in individuals with premature CAD (20.2% versus 10.8%), and was associated with a 3.1-fold increased risk of a premature event (P<¼0.02). Twice as many patients with premature CAD met the criteria for both elevated Lp(a) and phenotypic FH (10.7% vs 5.1%; P¼0.05) compared with non-premature CAD patients. The combination of elevated Lp(a) and FH conferred a 4-fold increased risk of premature CAD (P¼0.004). Conclusions: Elevated Lp(a) and phenotypic FH were commonly encountered in patients admitted to the CCU and were more frequent among those with premature CAD.
SAG196. APPLICABILITY OF THE LOW-DENSITY LIPOPROTEIN CHOLESTEROL GENE SCORE IN A SOUTH EUROPEAN POPULATION Cibelle Mariano1, 2, Marta Futema3, Steve E. Humphries3, Mafalda Bourbon1, 2. 1 Instituto Nacional de Saúde Doutor Ricardo Jorge - DPS, Lisboa, Portugal; 2 Biosystems & Integrative Sciences Institute (BioISI), Faculdade de Ci^ encias, Universidade de Lisboa, Lisboa, Portugal; 3 Institute of Cardiovascular Science - Centre for Cardiovascular Genetics, University College London, London, United Kingdom Aim: Previous studies have demonstrated that the co-inheritance of LDLC-raising alleles from 6 SNPs is associated with the Familial Hypercholesterolaemia (FH) phenotype. Here we investigate the applicability of the LDL-C genetic risk score in the Portuguese FH population. Methods: Overall, 1320 DNA samples from a population study (eCOR) and 254 from the Portuguese FH study (103 mutation positive (FH+), 151 mutation negative (FH-)) were genotyped for the 6 LDL-C genetic risk score SNPs. The LDL-C weighted score was calculated as previously described. The eCOR cohort was used to determine the score values for the healthy Portuguese population. Polygenic hypercholesterolaemia was defined as a score above the top quartile. Results: FH- (0.68±0.21) and FH+ (0.72±0.19) patients had significantly higher score values than eCOR (0.62±0.22) (P<<0.001), a large proportion being in the top quartile (FH-:38%, FH+:31%). FH- patients had higher score
e100
Abstracts / Atherosclerosis 263 (2017) e29ee110
values than FH+, although not significantly (P¼0.09). Also, less FH- patients were in the bottom quartile than FH+ (11% vs 20%, P¼0.035). Comparison of the UK control “Whitehall” sample and eCOR mean score values showed no significant differences (0.632±0.22 vs 0.62±0.22). Conclusions: The LDL-C genetic risk score was validated in the Portuguese population, and revealed that almost half of the FH- patients could have polygenic hypercholesterolaemia, while a small part might have unknown variants in a FH associated gene or in a new gene and should be investigated by exome sequencing.
SAG197. NATURAL HISTORY AND GENE EXPRESSION SIGNATURE OF PLATELET COUNT IN LIPOPROTEIN LIPASE DEFICIENCY e de Montr eal Karine Tremblay, Diane Brisson, Daniel Gaudet. Universit Community Genomic Medicine Centre and ECOGENE-21, Saguenay, Canada Aim: Platelet physiology is affected by the post-prandial status. Lipoprotein lipase deficiency (LPLD) is a rare post-prandial disease associated with severe hypertriglyceridemia, chylomicronemia and increased risk of pancreatitis and metabolic complications. Important fluctuations of the platelet count (PLT) in LPLD have been reported. The aim of this study is to describe the natural history and gene expression signature of PLT in LPLD. Methods: The historical PLT values of 42 LPLD adults have been reviewed. The gene expression profile of subjects with history of low (PLT <130 x 103m/L) vs normal PLT was compared using whole blood RNA samples hybridized on Affymetrix Human Gene 2.0 ST Array. Results: Over a 15 years period, 24/42 (57.1%) of LPLD patients presented PLT <130 x 103m/L at least once. Thrombocytopenia was severe (PLT <50 x 103m/L) in 4.8% of cases. No bleeding, petechia or bruising were noticed. Conversely, 14.3% of cases presented thrombocytosis (PLT >450 x103m/L) at least once. The gene expression profile of ten of these LPLD patients identified ten down-regulated (MMP9, CEACAM8, SRGAP2-AS1, SLC38A5, KCNJ15, DEFA3, LTF, RNF144B, CTSE, MMP8) and three up-regulated (MIR374A, SCARNA15 and MIR4774) annotated probes in low PLT group (n¼5) compared to normal PLT group (n¼5) (p-values <0.01; jfold changej >2). Conclusions: These results illustrate that LPLD is associated with important asymptomatic fluctuations of the PLT over time. The gene expression signature of low PLT in LPLD may contribute to understand the effect of post-prandial metabolism on platelets physiology. Fasting and postprandial analyses of platelet structure and functions in LPLD are ongoing.
SAG198. FATTY ACID-BINDING PROTEIN 5 AS A RESIDUAL RISK FOR ATHEROSCLEROTIC CARDIOVASCULAR DISEASE IN PATIENTS WITH FAMILIAL HYPERCHOLESTEROLEMIA Masatsune Ogura1, Masato Furuhashi2, Megumu Morimoto1, Megumi Matsumoto2, Tetsuji Miura2, Mariko Harada-Shiba1. 1 National Cerebral and Cardiovascular Center Research Institute, Suita, Japan; 2 Sapporo Medical University School of Medicine, Sapporo, Japan Aim: Aim: Fatty acid-binding protein (FABP) 4 and FABP5 play important roles in the development of atherosclerosis and that their impacts differentially involve macrophages. We hypothesized FABPs may partly explain residual atherosclerotic cardiovascular disease (ASCVD) risk in statintreated familial hypercholesterolemia (FH) patients. We investigated associations of plasma FABP4 and FABP5 levels with the presence of ASCVD and clinical features in these patients. Methods: Methods: Two hundred and nineteen heterozygous FH patients treated with statin were enrolled in this cross-sectional study. Plasma FABPs levels were measured using enzyme-linked immunosorbent assay kits. Additionally, we assessed Achilles tendon thickness and carotid intima-media thickness. Results: Results: Eighty-five patients (38.8%) were known to have ASCVD. In univariate analyses, both plasma FABP4 and FABP5 levels were higher in patients with ASCVD compared with those without ASCVD. However, only
increased FABP5 level was associated with the presence of ASCVD after adjustment for traditional risk factors (OR per 1-SD increase, 1.27; 95% CI, 1.03e1.57; P¼0.0233). Additionally, increased FABP5 level was also related to increased maximum carotid intima-media thickness (IMT) as well. Although these FABPs levels were related to mean carotid IMT as well as Achilles tendon thickness in univariate analyses, these correlations were attenuated after multiple linear regression analyses. Conclusions: Conclusions: Plasma FABP5 level was independently associated with the presence of ASCVD and asymptomatic atherosclerosis in heterozygous FH. In view of residual risks after treatment with statins, FABP5 might be a novel biomarker and a therapeutic target for preventing atherosclerosis in patients with FH.
SAG199. CARDIOVASCULAR RISK IN CHILDREN: THE CLINICAL RELEVANCE OF EARLY AND TIMELY STRATIFICATION ^s Gomes1, Catarina Branda ~o1, Mafalda Bourbon2, Fa tima Pinto1. 1 Centro Ine Hospitalar Lisboa Central, Lisbon, Portugal; 2 Instituto Nacional de Saúde, Lisbon, Portugal Aim: The increasing prevalence of cardiovascular risk factors in children needs a structured approach with early identification and treatment. We aimed at characterizing the methodology and the results in a Paediatric Cardiology centre with a specialized outpatient clinic in this field. Methods: Retrospective study was performed from chart review, and classic risk factors, anthropometry, and insulin-resistance index (HOMAIR) were analysed. Every patient is evaluated clinically. ECG, ecochardiogram and peripheral arterial tonometry (PAT) are routinelly obtained. Results: We studied 301 patients, 60% females, mean age 13.9 years (range 6-19) and mean BMI 29.7 (50 patients had BMI > 30). In the studied population, 2 or more classical cardiovascular risk factors were prevalent in 42% of patients. The lipid mean values were: total cholesterol (TC): 171,4±38,4 mg/dL; HDLc: 49,2 ± 15,9 mg/dL; LDLc 109,6±35,6 mg/dL and triglycerides: 93,5±62,1 mg/dL. Of these, 32 patients had high TC ( mean 233 mg/dL), with high atherogenicity index in 11. Heterozygotic Familial Hypercholesterolemia (FH) was confirmed in 6 patients, with various pathogenic mutations of LDLR gene. AMBP performed in 73 patients showed high blood pressure in 58 with 19 patients exclusively non-dipper. We found endothelial dysfunction in 38 patients with renal failure and dyslipidemia. Conclusions: A structured evaluation of cardiovascular risk factors in pediatric age in a selected population combining several indexes, TAP and AMBP was accurate to evaluate and follow these patients. This methodology also allowed selective testing for FH, allowing identification of 4 cases of heterozygotic FH in 2 families.
SAG200. MOLECULAR ANALYSIS OF 15 HOMOZYGOUS LAL-D PATIENTS FROM GREECE USING DBS SCREENING Elena Kamenet1, Vasiliki Mollaki2, John Hamilton3, Ekaterina Zakharova1, Euridiki Drogari2. 1 FSBI, Research Centre for Medical Genetics, Moscow, Russia; 2 Metabolic Unit, 1st Department of Pediatrics, National and Kapodistrian University of Athens, Athens, Greece; 3 Biochemistry Department, NHS Greater Glasgow & Clyde, Glasgow, United Kingdom Aim: Lysosomal acid lipase (LAL), encoded by the LIPA gene, catalyzes hydrolysis of cholesteryl esters and triglycerides. Mild splicing-junction mutation c.894G>A is considered as the most frequent mutation (about 60% of all defects in European populations). The aim of this study was to define the spectrum of LIPA mutations in Greek population. Methods: In 15 patients (6 male and 9 female, age from 4 to 27 years) from 13 unrelated Greek families LAL activity was determined using DBS by fluorometric analysis. In all these patients, their 26 parents and their 8 healthy siblings molecular analysis of LIPA gene was carried out. Coding sequence of LIPA was analyzed by direct sequencing (ABI3500).