ABSTRACT
Mutations in the LRRK2 gene, predominantly G2019S, have been reported in individuals with autosomal dominant inheritance and sporadic Parkinson’s disease (PD). The G2019S mutation has an age-dependent penetrance and evidence shows common ancestry. The clinical manifestations are indistinguishable from idiopathic PD. Its prevalence varies according to the population studied ranging from less than 0.1% in Asians to 41% in North African Arabs. This study aimed to identify G2019S mutation in Brazilian idiopathic PD patients. Method: We sampled 100 PD patients and 100 age- and gender-matched controls. Genetical analysis was accomplished by polymerase chain reaction (PCR). Results: No G2019S mutations were found in both patients with sporadic PD and controls. Conclusions: Our results may be explained by the relatively small sample size. .
Mutação no gene LRRK2, predominantemente G2019S, foi descrita em indivíduos com doença de Parkinson (DP) esporádica ou herança autossômica dominante. A penetrância da mutação varia com a idade e há evidências de ancestral comum. As manifestações clínicas são indistinguíveis da DP idiopática. Sua prevalência depende da população estudada e varia de 0,1% em asiáticos a 41% em árabes do norte africano. O objetivo desse estudo foi identificar a mutação G2019S em brasileiros com DP esporádica. Método: Foram testados 100 pacientes com DP e 100 controles pareados por idade e sexo. A análise genética foi realizada pela reação em cadeia por polimerização (PCR). Resultados: Não foi encontrada a mutação G2019S nem nos pacientes com DP nem nos controles. Conclusão: É possível que nossos resultados sejam devidos ao pequeno número de pacientes incluídos. .
Subject(s)
Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Mutation Rate , Parkinson Disease/genetics , Protein Serine-Threonine Kinases/genetics , Age Factors , Age of Onset , Brazil , Case-Control Studies , Polymerase Chain Reaction , Parkinson Disease/ethnologyABSTRACT
BACKGROUND: Rett syndrome (RS) is a severe neurodevelopmental X-linked dominant disorder caused by mutations in the MECP2 gene. PURPOSE: To search for point mutations on the MECP2 gene and to establish a correlation between the main point mutations found and the phenotype. METHOD: Clinical evaluation of 105 patients, following a standard protocol. Detection of point mutations on the MECP2 gene was performed on peripheral blood DNA by sequencing the coding region of the gene. RESULTS: Classical RS was seen in 68 percent of the patients. Pathogenic point mutations were found in 64.1 percent of all patients and in 70.42 percent of those with the classical phenotype. Four new sequence variations were found, and their nature suggests patogenicity. Genotype-phenotype correlations were performed. CONCLUSION: Detailed clinical descriptions and identification of the underlying genetic alterations of this Brazilian RS population add to our knowledge of genotype/phenotype correlations, guiding the implementation of mutation searching programs.
INTRODUÇÃO: A síndrome de Rett é uma grave doença do neurodesenvolvimento ligada ao X dominante, causada por mutações no gene MECP2. OBJETIVOS: Identificar mutações de ponto no gene MECP2 e estabelecer uma correlação entre as principais mutações encontradas e o fenótipo. MÉTODO: Avaliação clínica de 105 pacientes, seguindo um protocolo estabelecido. A identificação de mutações de ponto foi realizada em DNA de sangue periférico por sequenciamento da região codificante do gene amplificada por PCR. RESULTADOS: Em 68 por cento dos pacientes observou-se o quadro clássico da síndrome. Mutações de ponto patogênicas foram encontradas em 64,1 por cento dos pacientes e em 70,42 por cento das pacientes com o quadro clássico. Quatro novas variações de seqüência foram identificadas e sua natureza sugere patogenicidade. Correlações genótipo-fenótipo foram estabelecidas. CONCLUSÃO: Descrições clínicas detalhadas desta população brasileira de pacientes acrescenta conhecimento às correlações genótipo-fenótipo nesta grave condição, que podem auxiliar na implantação de programas de triagem de mutações.
Subject(s)
Adolescent , Adult , Child , Child, Preschool , Female , Humans , Infant , Male , Young Adult , DNA , Genetic Association Studies , /genetics , Point Mutation/genetics , Rett Syndrome/genetics , Brazil , Polymerase Chain Reaction , Young AdultABSTRACT
Em 1999, as células-tronco foram eleitas "Scientific Breakthrough of the Year" (avanço científico do ano) pela revista Science¹. Naquele ano, foi demonstrado que células-tronco de tecidos adultos mantinham a capacidade de se diferenciar em outros tipos de tecidos. No ano anterior, as primeiras linhagens de células-tronco embrionárias humanas foram estabelecidas. Desde então, o número de artigos científicos sobre células-tronco vem crescendo exponencialmente, onde novos paradigmas são estabelecidos. Neste artigo, farei uma revisão da área de células-tronco com um foco especial em seu uso como agente terapêutico em doenças comuns como diabetes e cardiopatias. As células-tronco serão tratadas em dois grupos distintos: as embrionárias e as adultas. Enquanto o potencial de diferenciação das primeiras está bem caracterizado em camundongos e em humanos, seu uso em terapia celular e em pesquisa tem sido dificultado por questões de histocompatibilidade, segurança e ética. Em contraste, células-tronco adultas não apresentam estes empecilhos, apesar da extensão de sua plasticidade ainda estar sob investigação. Mesmo assim, diversos testes clínicos em humanos estão em andamento utilizando células-tronco adultas, principalmente derivadas da medula óssea. Discutirei ainda a importância de se trabalhar com as duas classes de células-tronco humanas de forma a se cumprir suas promessas terapêuticas.
Stem cells were elected 'Breakthrough of the Year' by Science¹ magazine in 1999, having shown that stem cells from adult tissues retained the ability to differentiate into other tissue types. During the previous year, the first human embryo stem cell lines were established. Since then, the number of scientific papers on stem cells has been increasing exponentially, establishing new paradigms that are rapidly challenged by subsequent experiments. This paper reviews the stem cell research field, divided into two groups: embryo and adult stem cells. While the differentiation potential of the former is well characterized in mice and humans, their use in cell therapy and research has been hampered by histocompatibility, safety and ethical issues. In contrast, adult stem cells do not present these problems. However, the extent of their plasticity is still under investigation. Nevertheless, numerous clinical trials in humans are under way, mainly with stem cells derived from bone marrow. This paper discusses discuss the importance of working with both classes of human stem cells in order to fulfill the promise of stem cell therapies.
Subject(s)
Humans , Stem Cells , Embryo Disposition , Public Health , Cell- and Tissue-Based TherapySubject(s)
Humans , Pregnancy , Infant, Newborn , Infant , Adult , Tay-Sachs Disease/diagnosis , Tay-Sachs Disease/etiology , Tay-Sachs Disease/prevention & control , Heredodegenerative Disorders, Nervous System , Jews , National Health Programs/statistics & numerical data , National Health Programs/trends , BrazilABSTRACT
CONTEXT: Tay-Sachs disease is an autosomal recessive disease characterized by progressive neurologic degeneration, fatal in early childhood. In the Ashkenazi Jewish population the disease incidence is about 1 in every 3,500 newborns and the carrier frequency is 1 in every 29 individuals. Carrier screening programs for Tay-Sachs disease have reduced disease incidence by 90 percent in high-risk populations in several countries. The Brazilian Jewish population is estimated at 90,000 individuals. Currently, there is no screening program for Tay-Sachs disease in this population. OBJECTIVE: To evaluate the importance of a Tay-Sachs disease carrier screening program in the Brazilian Jewish population by determining the frequency of heterozygotes and the acceptance of the program by the community. SETTING: Laboratory of Molecular Genetics - Institute of Biosciences - Universidade de Säo Paulo. PARTICIPANTS: 581 senior students from selected Jewish high schools. PROCEDURE: Molecular analysis of Tay-Sachs disease causing mutations by PCR amplification of genomic DNA, followed by restriction enzyme digestion. RESULTS: Among 581 students that attended educational classes, 404 (70 percent) elected to be tested for Tay-Sachs disease mutations. Of these, approximately 65 percent were of Ashkenazi Jewish origin. Eight carriers were detected corresponding to a carrier frequency of 1 in every 33 individuals in the Ashkenazi Jewish fraction of the sample. CONCLUSION: The frequency of Tay-Sachs disease carriers among the Ashkenazi Jewish population of Brazil is similar to that of other countries where carrier screening programs have led to a significant decrease in disease incidence. Therefore, it is justifiable to implement a Tay-Sachs disease carrier screening program for the Brazilian Jewish population