Segregación familiar de mutaciones en los genes LPL, LMF1 Y APOA5 en sujetos con Hipertrigliceridemias primarias

La gran mayoría las de hipertrigliceridemias graves primarias (HTG), con un rango de triglicéridos entre 500 y 2000 mg/dl, se diagnostican en adultos, y sus bases moleculares no se han dilucidado completamente. Con objeto de conocer la prevalencia de variantes genéticas asociadas con hipertrigliceridemia en la población general, hemos secuenciado los promotores, los exones, y las regiones exón-intrón de los genes LPL, APOA5 y LMF1 en 112 pacientes con HTG severa primaria. Trece pacientes (11,6%) resultaron portadores de 11 variantes raras asociadas a HTG en los analizados, 1 de las cuales se describe por primera vez en este trabajo. Hemos identificado polimorfismos que se asocian con la HTG ya que se encuentran en una frecuencia alélica diferente de la que se observa en población general: c.281T>G, p.Asn36Asn, p.Val135Val, c.430-6C>T, p.Pro234Leu, p.Thr379Ile y p.Ser474X en LPL; c.194-28 T>G y c.729+18C>G en LMF1; y c.-3A>G, p.Ser19Trp, p.Asp37Glu, c.162-43A >G y c.*158 T>C en APOA5. Además, llevamos a cabo un análisis bioinformático de todas las variantes encontradas, observando los siguientes cambios como potencialmente dañinos y causales de HTG: c.-241G>C, c.1018+2G>A, p.Gln16GlufsX39, p.Asp36Asn, p.Gln133X, p.Pro234Leu, p.Gly215Glu, c.430-6C>T y p.Asn318Ser de LPL, p.Arg364Gln, P.Arg451Trp, p.Pro562Arg y p.Leu85Leu de LMF1, p.Pro253Leu y p.Ser19Trp de APOA5. Nuestros resultados confirman que la HTG primaria es altamente heterogénea en su etiología y se asocia con la acumulación de variantes comunes y raras en los genes involucrados en el metabolismo de los TG. En conclusión, nuestros resultados sugieren que la HTG primaria del adulto con TG alrededor de 500-1000 mg/dl presenta mayor cantidad de variantes genéticas respecto a la población general, con una combinación de mutaciones de efecto entre moderado y agresivo, y polimorfismos clásicamente asociados con la enfermedad

Mutaciones en el gen de ApoA5 en sujetos con hipertrigliceridemia grave. Estudio de la prevalencia en una zona sanitaria de Aragón.

Las hipertrigliceridemias (HTG) son una dislipemia común que se ha asociado con el desarrollo de enfermedad cardiovascular. La HTG grave, definida con triglicéridos > 500 mg/dl, suele estar causada por mutaciones en genes del catabolismo de los triglicéridos y se asocia con predisposición a pancreatitis aguda. Mutaciones en APOA5 que causan baja concentración de Apo AV se asocian con la HTG grave. El objetivo de este estudio fue identificar las variantes génicas, comunes y no comunes en el gen candidato APOA5 en sujetos con HTG grave de causa primaria y analizar su asociación con la enfermedad. Para llevar a cabo este trabajo, se seleccionaron 66 pacientes procedentes de Centro de Salud de la Almozara de Zaragoza en los que se extrajo el DNA y se amplificaron mediante PCR y se secuenciaron el promotor, exones y nexos de unión exón-intrón del gen APOA5. Las frecuencias de las variantes encontradas se compararon con la población europea analizada en el proyecto 1000 Genomas y se analizaron con herramientas bioinformáticas para predecir su efecto. El 4,55% de los pacientes resultaron portadores de 2 variantes raras: p.Gln97*, previamente descrita como causal de HTG y p.Leu173Pro, identificada por primera vez en este trabajo. El análisis bioinformático de la mutación p.Leu173Pro mostró controversia. Además, las variantes comunes c.-3A>G, p.Ser19Trp, p.Iso44Iso y c.162-43A>G presentaron una frecuencia significativamente superior en los sujetos con HTG frente a la población de los 1000 Genomas. A partir de este trabajo podemos concluir que variantes comunes y no comunes en el gen APOA5 pueden estar implicadas en la patogenicidad de la HTG grave

Assessment of plasma chitotriosidase activity, CCL18/PARC concentration and NP-C suspicion index in the diagnosis of Niemann-Pick disease type C: a prospective observational study

Additional file 1. Patient questionnaire

A genetic variant in the LDLR promoter is responsible for part of the LDL-cholesterol variability in primary hypercholesterolemia

BACKGROUND: GWAS have consistently revealed that LDLR locus variability influences LDL-cholesterol in general population. Severe LDLR mutations are responsible for familial hypercholesterolemia (FH). However, most primary hypercholesterolemias are polygenic diseases. Although Cis-regulatory regions might be the cause of LDL-cholesterol variability; an extensive analysis of the LDLR distal promoter has not yet been performed. We hypothesized that genetic variants in this region are responsible for the LDLR association with LDL-cholesterol found in GWAS. METHODS: Four-hundred seventy-seven unrelated subjects with polygenic hypercholesterolemia (PH) and without causative FH-mutations and 525 normolipemic subjects were selected. A 3103 pb from LDLR (-625 to +2468) was sequenced in 125 subjects with PH. All subjects were genotyped for 4 SNPs (rs17242346, rs17242739, rs17248720 and rs17249120) predicted to be potentially involved in transcription regulation by in silico analysis. EMSA and luciferase assays were carried out for the rs17248720 variant. Multivariable linear regression analysis using LDL-cholesterol levels as the dependent variable were done in order to find out the variables that were independently associated with LDL-cholesterol. RESULTS: The sequencing of the 125 PH subjects did not show variants with minor allele frequency ≥ 10%. The T-allele from g.3131C > T (rs17248720) had frequencies of 9% (PH) and 16.4% (normolipemic), p < 0.00001. Studies of this variant with EMSA and luciferase assays showed a higher affinity for transcription factors and an increase of 2.5 times in LDLR transcriptional activity (T-allele vs C-allele). At multivariate analysis, this polymorphism with the lipoprotein(a) and age explained ≈ 10% of LDL-cholesterol variability. CONCLUSION: Our results suggest that the T-allele at the g.3131 T > C SNP is associated with LDL-cholesterol levels, and explains part of the LDL-cholesterol variability. As a plausible cause, the T-allele produces an increase in LDLR transcriptional activity and lower LDL-cholesterol levels

Genetic Variants of <i>LDLR</i> and <i>PCSK9</i> Associated with Variations in Response to Antihypercholesterolemic Effects of Armolipid Plus with Berberine

<div><p>Background</p><p>Armolipid Plus (AP) is a nutraceutical that contains policosanol, fermented rice with red yeast, berberine, coenzyme Q10, folic acid, and astaxanthin. It has been shown to be effective in reducing plasma LDL cholesterol (LDLc) levels. In the multicenter randomized trial NCT01562080, there was large interindividual variability in the plasma LDLc response to AP supplementation. We hypothesized that the variability in LDLc response to AP supplementation may be linked to <i>LDLR</i> and <i>PCSK9</i> polymorphisms.</p><p>Material and Methods</p><p>We sequenced the <i>LDLR</i> 3′ and 5′ untranslated regions (UTR) and the <i>PCSK9</i> 5′ UTR of 102 participants with moderate hypercholesterolemia in trial NCT01562080. In this trial, 50 individuals were treated with AP supplementation and the rest with placebo.</p><p>Results</p><p>Multiple linear regression analysis, using the response of LDLc levels to AP as the dependent variable, revealed that polymorphisms rs2149041 (c.-3383C>G) in the <i>PCSK9</i> 5′ UTR and rs14158 (c.*52G>A) in the <i>LDLR</i> 3′ UTR explained 14.1% and 6.4%, respectively, of the variability after adjusting for gender, age, and BMI of individuals. Combining polymorphisms rs2149041 and rs14158 explained 20.5% of this variability (<i>p</i> < 0.004).</p><p>Conclusions</p><p>Three polymorphisms in the 3′ UTR region of <i>LDLR</i>, c.*52G>A, c.*504G>A, and c.*773A>G, and two at the 5′ UTR region of <i>PCSK9</i>, c.−3383C>G and c.−2063A>G, were associated with response to AP. These results could explain the variability observed in the response to berberine among people with moderate hypercholesterolemia, and they may be useful in identifying patients who could potentially benefit from supplementation with AP.</p></div

LDL cholesterol response to Armolipid Plus® in study subjects classified according to be carriers of the minor allele of the <i>PCSK9</i> and <i>LDLR</i> Variants.

<p>LDL cholesterol response to Armolipid Plus® in study subjects classified according to be carriers of the minor allele of the <i>PCSK9</i> and <i>LDLR</i> Variants.</p

Study subjects classified according to status as carriers of c.−3383C>G <i>PCSK9</i> and c.*52G>A <i>LDLR</i> variants and response of LDL cholesterol levels to Armolipid Plus.

<p>Study subjects classified according to status as carriers of c.−3383C>G <i>PCSK9</i> and c.*52G>A <i>LDLR</i> variants and response of LDL cholesterol levels to Armolipid Plus.</p