20 research outputs found
Polyunsaturated fatty acid status in treated isovaleric acidemia patients
Nutritional deficiencies are frequently observed when treating patients with inborn errors of metabolism due to an unbalanced diet. Thus far, patients with isovaleric acidemia (IVA) who adhere to a restricted protein diet have not been investigated in this respect. We hypothesize that these patients may have a polyunsaturated fatty acid (PUFA) deficiency, leading to potential clinical complications. We examined the nutritional status by reporting on potential deficiencies in PUFAs in treated IVA patients. A general clinical chemistry work-up as well as gas chromatography flame ionization detector analysis was performed to determine PUFAs in the plasma of 10 IVA patients. The general clinical chemistry tests did not indicate severe hematological abnormalities or nutritional insufficiencies. We identified a significant reduction in plasma PUFA levels, especially in omega-3 (all acids, P <0.001) and omega-6 (in particular 20:3n-6 P <0.0001 and 20:4n-6 P=0.0005) fatty acids. In addition, an elevation in omega-9 fatty acids, with the exception of 20:3n-9 and C22:1n-9, was not suggestive of complete essential fatty acid deficiency but rather indicative of isolated and/or combined omega-3 and omega-6 fatty acid depletion. This study emphasizes the potential nutritional insufficiencies that may occur because of therapeutic intervention in IV
Clinical variability of isovaleric acidemia in a genetically homogeneous population
Isovaleric acidemia (IVA) is one of the most common organic acidemias found in South Africa. Since 1983, a significant number of IVA cases have been identified in approximately 20,000 Caucasian patients screened for metabolic defects. IVA is caused by an autosomal recessive deficiency of isovaleryl-CoA dehydrogenase (IVD) resulting in the accumulation of isovaleryl-CoA and its metabolites. In total, 10 IVA patients and three carriers were available for phenotypic and genotypic investigation in this study. All patients were found to be homozygous for a single c.367 G > A (p.G123R) mutation. The amino acid substitution of a glycine to arginine resulted in a markedly reduced steady-state level of the IVD protein, which explains the nearly complete lack of IVD enzyme activity as assessed in fibroblast homogenates. Despite the genetic homogeneity of this South African IVA group, the clinical presentation varied widely, ranging from severe mental handicap and multiple episodes of metabolic derangement to an asymptomatic state. The variation may be due to poor dietary intervention, delayed diagnosis or even epigenetic and polygenetic factors of unknown origi
Evolutionary history of Phakopsora pachyrhizi (the Asian soybean rust) in Brazil based on nucleotide sequences of the internal transcribed spacer region of the nuclear ribosomal DNA
Phakopsora pachyrhizi has dispersed globally and brought severe economic losses to soybean growers. The fungus has been established in Brazil since 2002 and is found nationwide. To gather information on the temporal and spatial patterns of genetic variation in P. pachyrhizi , we sequenced the nuclear internal transcribed spacer regions (ITS1 and ITS2). Total genomic DNA was extracted using either lyophilized urediniospores or lesions removed from infected leaves sampled from 26 soybean fields in Brazil and one field in South Africa. Cloning prior to sequencing was necessary because direct sequencing of PCR amplicons gave partially unreadable electrophoretograms with peak displacements suggestive of multiple sequences with length polymorphism. Sequences were determined from four clones per field. ITS sequences from African or Asian isolates available from the GenBank were included in the analyses. Independent sequence alignments of the ITS1 and ITS2 datasets identified 27 and 19 ribotypes, respectively. Molecular phylogeographic analyses revealed that ribotypes of widespread distribution in Brazil displayed characteristics of ancestrality and were shared with Africa and Asia, while ribotypes of rare occurrence in Brazil were indigenous. The results suggest P. pachyrhizi found in Brazil as originating from multiple, independent long-distance dispersal events
Diversidade genética em cultivares locais e comerciais de feijão baseada em marcadores RAPD Genetic diversity in cultivars and landraces of common bean based on RAPD markers analysis
O objetivo deste trabalho foi caracterizar a diversidade genética dentro e entre cultivares locais e comerciais de feijão, por meio de marcadores RAPD, e avaliar a capacidade destes em agrupar genótipos de feijão de acordo com o centro de domesticação e coloração de semente. Foram avaliadas 35 cultivares, 13 comerciais e 22 locais, de diversas regiões do Rio Grande do Sul. As distâncias genéticas foram obtidas pelo complemento do coeficiente de similaridade de Sorensen-Dice e a representação simplificada destas distâncias realizada mediante um dendrograma. Marcadores RAPD foram eficientes ao agrupar cultivares de acordo com o centro de domesticação, mas não foram capazes de separar as cultivares de acordo com a coloração da semente. Cultivares locais e comerciais, mesoamericanas, foram agrupadas separadamente. Cultivares comerciais, em cultivo no Rio Grande do Sul apresentam alto grau de similaridade.<br>The objective of this work was to characterize the genetic diversity within and among cultivars and landraces of common bean from RAPD markers analysis, and to evaluate the capacity of this markers in clustering common bean genotypes according to domestication centers and seed color. Thirty five common bean genotypes including 13 commercial cultivars and 22 landraces, from State of Rio Grande do Sul, Brazil, were evaluated. Genetic distances were calculated using Sorensen-Dice's similarity coefficient, displayed in a dendrogram. RAPD markers were efficient in separating cultivars and landraces according to domestication centers, but not according to seed color. Mesoamerican commercial cultivars and landraces have been clustered in different groups. A high degree of similarity was observed among cultivars in use in Rio Grande do Sul
An overview of a cohort of South African patients with mitochondrial disorders
Mitochondrial disorders are frequently encountered
inherited diseases characterized by unexplained
multisystem involvement with a chronic, intermittent, or
progressive nature. The objective of this paper is to describe
the profile of patients with mitochondrial disorders in South
Africa. Patients with possible mitochondrial disorders were
accessed over 10 years. Analyses for respiratory chain and
pyruvate dehydrogenase complex enzymes were performed
on muscle. A diagnosis of a mitochondrial disorder was
accepted only if an enzyme activity was deficient. Sixtythree
patients were diagnosed with a mitochondrial disorder,
including 40 African, 20 Caucasian, one mixed ancestry, and
two Indian patients. The most important findings were the
difference between African patients and other ethnicities:
respiratory chain enzyme complexes CI+III or CII+III
deficiencies were found in 52.5% of African patients, being
of statistical significance (p value=0.0061). They also
presented predominantly with myopathy (p value=
0.0018); the male:female ratio was 1:1.2. Twenty-five
(62.5%) African patients presented with varying degrees
of a myopathy accompanied by a myopathic face, high
palate, and scoliosis. Fourteen of these 25 also had ptosis
and/or progressive external ophthalmoplegia. No patients of
other ethnicities presented with this specific myopathic
phenotype. Caucasian patients (16/20) presented predominantly
with central nervous system involvement. Of the
South African pediatric neurology patients, Africans are
more likely to present with myopathy and CII+III deficiency,
and Caucasian patients are more likely to present with
encephalopathy or encephalomyopath