Association of mitochondrial haplogroup J and mtDNA oxidative damage in two different North Spain elderly populations.

This work investigates the association between longevity, mitochondrial DNA (mtDNA) variants and oxidative DNA damage in an older than 85 years population. The participants, similar in genetic and cultural background as well as gender distribution, come from villages near to the Pyrenees Mountains (900-1,400 m altitude) (n = 69) and the Ebro's Valley (200-300 m altitude) (n = 69) in Spain. Our results show an accumulation of the haplogroup J in elderly individuals with an over-representation of J2 in Pyrenees group but not in the Ebro's Valley, the former associating with a diminished DNA damage. In conclusion, our results suggest that J mitochondrial variant, that induce lower mtDNA damage, could present a phenotypic survival advantage to environmental conditions and, thus, accumulate in elderly population.

[Polymorphisms in cystathionine beta-synthase and methylenetetrahydrofolate reductase genes as risk factors for cerebral vascular disease]. / Polimorfismos en los genes cistationina beta-sintasa y metilentetrahidrofolato reductasa como factores de riesgo de enfermedad vascular cerebral.

BACKGROUND AND OBJECTIVE: High plasma total homocysteine (tHcy), low dietary intake of folate and other B vitamins, and genetic polymorphisms related to the metabolism of homocysteine may interactively contribute to the risk of cerebral vascular disease (CVD). We explored interrelations between total homocysteine levels and mutations in genes for the two key enzymes in methionine-homocysteine metabolism. PATIENTS AND METHOD: We analyzed two polymorphisms, C677T in the MTHFR gene and 844ins68 in the CBS gene. We assessed their association with fasting homocysteine in 64 patients with CVD, and in 159 controls. RESULTS: No differences in CBS and MTHFR genotype frequencies between cases and controls were found (C677T p = 0.87 and 844ins68 p = 0.63), nor was a particular CBS and MTHFR genotype associated with an elevated risk of CVD. None of the genotypes defined by the CBS and MTHFR variants studied showed an association with elevated fasting homocysteine concentrations (C677T p = 0.07 and 844ins68 p = 0.47). CONCLUSIONS: We did not find any indication that genetic variation in the CBS and MTHFR genes are associated with homocysteine-related risk of CVD, hence needing further investigation. The contributions to total plasma homocysteine levels of the common mutations of genes coding for the enzymes controlling homocysteine metabolism are modest.

Polimorfismos en los genes cistationina â -sintasa y metilentetrahidrofolato reductasa como factores de riesgo de enfermedad vascular cerebral / Polymorphisms in cystathionine â -synthase and methylenetetrahydrofolate reductase genes as risk factors for cerebral vascular disease

FUNDAMENTO Y OBJETIVO: La interacción entre altas concentraciones de homocisteína plasmática, baja ingesta de folato y otras vitaminas B, y la presencia de polimorfismos en genes relacionados con el metabolismo de la homocisteína, puede aumentar el riesgo de padecer una enfermedad cerebrovascular (ECV). Se ha estudiado la interrelación entre la concentración de homocisteína y la presencia de mutaciones en dos genes relacionados con el metabolismo metionina homocisteína. PACIENTES Y MÉTODO: Se han analizado dos polimorfismos, C677T en el gen MTHFR y 844ins68 en el gen CBS, en 64 pacientes con ECV y 159 controles sanos, estableciendo su posible asociación con la homocisteína total. RESULTADOS: No se han encontrado diferencias en las frecuencias enotipificadas de los genes CBS y MTHFR entre casos y controles (C677T, p = 0,87, y 844ins68, p = 0,63). Ningún genotipo estuvo asociado con un mayor riesgo de ECV. Tampoco se pudo establecer su asociación con un aumento de la concentración de homocisteína total (C677T, p = 0,07, y 844ins68, p = 0,47). CONCLUSIONES: No se ha observado ningún indicio de asociación entre las variables genotipificadas en los genes CBS y MTHFR y la concentración de homocisteína que supongan un aumento del riesgo de ECV. La contribución de estas mutaciones al incremento de la concentración de homocisteína es modesto

BACKGROUND AND OBJECTIVE: High plasma total homocysteine (tHcy), low dietary intake of folate and other B vitamins, and genetic polymorphisms related to the metabolism of homocysteine may interactively contribute to the risk of cerebral vascular disease (CVD). We explored interrelations between total homocysteine levels and mutations in genes for the two key enzymes in methionine-homocysteine metabolism. PATIENTS AND METHOD: We analyzed two polymorphisms, C677T in the MTHFR gene and 844ins68 in the CBS gene. We assessed their association with fasting homocysteine in 64 patients with CVD, and in 159 controls. RESULTS: No differences in CBS and MTHFR genotype frequencies between cases and controls were found (C677T p = 0.87 and 844ins68 p = 0.63), nor was a particular CBS and MTHFR genotype associated with an elevated risk of CVD. None of the genotypes defined by the CBS and MTHFR variants studied showed an association with elevated fasting homocysteine concentrations (C677T p = 0.07 and 844ins68 p = 0.47).CONCLUSIONS: We did not find any indication that genetic variation in the CBS and MTHFR genes are associated with homocysteine related risk of CVD, hence needing further investigation. The contributions to total plasma homocysteine levels of the common mutations of genes coding for the enzymes controlling homocysteine metabolism are modest