RESUMO
Mastitis is the main disease entity affecting dairy farms in the Colombian High Plains of northern Antioquia, Colombia. However, no previous epidemiologic studies have determined the characteristics that increase the risk of infection in this region, where manual milking is still the prevailing system of milking. A 24-mo longitudinal study was designed to identify the predominant mastitis pathogens and important herd- and cow-level risk factors. Monthly visits were made to 37 commercial dairy farms to collect herd- and cow-level data and milk samples. Herd size varied from 6 to 136 cows (mean 37.0, median 29). Herd-level factors included type of milking system (manual or mechanical) and a range of management practices recommended by the National Mastitis Council (Madison, WI) to prevent mastitis. Individual cow-level risk factors included parity, stage of lactation, breed, udder hygiene, and lameness. A logistic regression analysis was used to investigate associations between herd- and cow-level risk factors with the presence of subclinical mastitis and infection caused by Streptococcus agalactiae at the quarter level. A quarter was considered to have subclinical mastitis if it had a positive California Mastitis Test and was subsequently confirmed to have a somatic cell count of ≥200,000 cells/mL. Any cow with one or more quarters with subclinical mastitis was considered to have subclinical mastitis at the cow level. Using 17,622 cow observations, the mean prevalence of subclinical mastitis at the cow level was 37.2% (95% confidence interval: 31.2, 43.3) for the first month and did not substantially change throughout the study. The predominant microorganisms isolated from quarters meeting the subclinical mastitis definition were contagious pathogens, including Strep. agalactiae (34.4%), Corynebacterium spp. (13.2%), and Staphylococcus aureus (8.0%). Significant variables associated with subclinical mastitis risk at the quarter level included being a purebred Holstein cow, higher parity, and increased months in milk. Variables that were protective for mastitis risk included being a crossbreed cow and adequate premilking udder hygiene. Significant variables associated with Strep. agalactiae infection were higher parity, increased months in milk, and manual milking. Variables that were protective were postmilking teat dipping and adequate cleaning of the udder. The results highlight the importance of hygiene practices in contagious mastitis control in manually milked herds.
Assuntos
Infecções Assintomáticas/epidemiologia , Bactérias/isolamento & purificação , Infecções Bacterianas/veterinária , Mastite Bovina/epidemiologia , Animais , Bactérias/classificação , Infecções Bacterianas/epidemiologia , Infecções Bacterianas/microbiologia , Bovinos , Colômbia/epidemiologia , Indústria de Laticínios , Feminino , Estudos Longitudinais , Mastite Bovina/microbiologia , Prevalência , Fatores de RiscoRESUMO
In previous studies of a genetic isolate, we identified significant linkage of attention deficit hyperactivity disorder (ADHD) to 4q, 5q, 8q, 11q and 17p. The existence of unique large size families linked to multiple regions, and the fact that these families came from an isolated population, we hypothesized that two-locus interaction contributions to ADHD were plausible. Several analytical models converged to show significant interaction between 4q and 11q (P<1 × 10(-8)) and 11q and 17p (P<1 × 10(-6)). As we have identified that common variants of the LPHN3 gene were responsible for the 4q linkage signal, we focused on 4q-11q interaction to determine that single-nucleotide polymorphisms (SNPs) harbored in the LPHN3 gene interact with SNPs spanning the 11q region that contains DRD2 and NCAM1 genes, to double the risk of developing ADHD. This interaction not only explains genetic effects much better than taking each of these loci effects by separated but also differences in brain metabolism as depicted by proton magnetic resonance spectroscopy data and pharmacogenetic response to stimulant medication. These findings not only add information about how high order genetic interactions might be implicated in conferring susceptibility to develop ADHD but also show that future studies of the effects of genetic interactions on ADHD clinical information will help to shape predictive models of individual outcome.
Assuntos
Transtorno do Deficit de Atenção com Hiperatividade/genética , Cromossomos Humanos Par 11/genética , Ligação Genética/genética , Predisposição Genética para Doença/genética , Receptores Acoplados a Proteínas G/genética , Receptores de Peptídeos/genética , Ácido Aspártico/análogos & derivados , Ácido Aspártico/metabolismo , Transtorno do Deficit de Atenção com Hiperatividade/tratamento farmacológico , Encéfalo/metabolismo , Estudos de Casos e Controles , Colina/metabolismo , Glutamina/metabolismo , Humanos , Inositol/metabolismo , Espectroscopia de Ressonância Magnética/métodos , Metilfenidato/uso terapêutico , Polimorfismo de Nucleotídeo Único/genética , PrótonsRESUMO
The Taenia solium larva causes cysticercosis in pigs, as well as economic losses for farmers and taeniosis in humans, constituting a public health problem. Infested pigs must therefore be identified before they enter the food chain. To this end, a dot blot assay was developed for the immunodiagnosis of porcine cysticercosis. A study was made of 44 pigs from different areas of Colombia that had all tested positive to cysticercosis, both by necropsy and the Western blot technique. Another group was formed comprising 44 pigs that had all tested negative to Western blot and necropsy. After analysing these 88 samples to validate the diagnostic assay, the result was a sensitivity of 86.4% and a specificity of 93.2%. The dot blot assay proved useful in diagnosing porcine cysticercosis. As the assay is easy to use in laboratories in endemic areas, as well as under field conditions, it is also appropriate for epidemiological studies.
Assuntos
Anticorpos Anti-Helmínticos/análise , Cisticercose/veterinária , Cysticercus/imunologia , Immunoblotting/veterinária , Doenças dos Suínos/diagnóstico , Animais , Cisticercose/diagnóstico , Cisticercose/epidemiologia , Prevalência , Sensibilidade e Especificidade , SuínosRESUMO
INTRODUCTION: The benign chorea hereditary (BCH, OMIM 118700) represents a childhood movement disorder characterized by its early onset, a slow progressive course (mostly stable) and the absence of mental compromise, which contrast with the clinical features exhibited by the Huntington Disease. CASE REPORTS: Here we describe a multigenerational, extended and inbreed family belonging to a genetic isolate, the Paisa community from Antioquia Colombia, with seven children exhibiting clinical features of BCH. Even though some patients with BCH are heterozygous for a dominant mutation in the thyroid transcription factor-1 gene (TITF1), the pattern in this family resembles a recessive mode of inheritance, which suggests that genetic heterogeneity may be playing a role. CONCLUSION: Currently, linkage analysis is underway to determine if TITF1 is the gene responsible for this movement disorder in this family.
Assuntos
Coreia/genética , Criança , Pré-Escolar , Coreia/diagnóstico , Colômbia , Consanguinidade , Diagnóstico Diferencial , Humanos , Doença de Huntington/diagnóstico , Masculino , LinhagemRESUMO
INTRODUCTION: Cysticercosis (CC) caused by Taenia solium in humans and in pigs is endemic in many rural communities in developing countries. The use of Western blot assays (WB) to determine T. solium antibodies has become the best serological tool available to date for identifying positive individuals in field conditions. AIMS: The aim of this study was to determine the prevalence of T. solium antibodies in humans and in pigs in two rural communities in Antioquia, Colombia. PATIENTS, MATERIALS AND METHODS: Serological identification of humans and pigs with T. solium antibodies was performed using WB assays in two communities in Ituango, Antioquia. During the study, demographic variables, housing and health conditions were taken into account. Contingency tables were drawn up using c2 to compare the proportion of seronegative individuals and seropositive individuals with headache, fainting or convulsions. RESULTS: The prevalence of human and porcine CC obtained was 2.23 and 6.82% in Pascuita and 1.17 and 2.33% in Guacharaquero, both respectively. Of the 11 WB positive patients evaluated by imaging techniques, two individuals were found to have single calcifications in the TAC scan and RMI showed another to have an unspecified lesion. The prevalence of infection in humans and in pigs in two rural communities in the north of the district of Antioquia, Colombia, shows that CC is endemic and that steps must be taken to control it.
Assuntos
Anticorpos/metabolismo , Cisticercose/epidemiologia , Cisticercose/imunologia , Taenia solium/imunologia , Animais , Anticorpos/imunologia , Colômbia/epidemiologia , Cisticercose/patologia , Humanos , Testes Sorológicos , SuínosRESUMO
INTRODUCTION: There are more than 40 clinical types of epilepsy classified according to aetiology and/or mode of clinical onset. The term idiopathic epilepsy is reserved for cases with convulsions but no detectable structural lesions of the brain or neurological anomalies. DEVELOPMENT AND CONCLUSIONS: In spite of many studies confirming the importance of genetic factors in the occurrence of idiopathic epilepsy, these appear to be complex and probably involve a locus of variable expression or several loci with similar phenotype expression (epistaxis). Also, environmental factors have variable effects. In recent years the principal genes involved in susceptibility to develop epilepsy have been mapped. In this way one mitochondrial and three autosomic genes have been cloned as responsible for the development of certain forms of this disorder. Also several studies of genetic linkage have given evidence, sometimes inconsistent, regarding the influence of another five loci in the susceptibility to develop epilepsy (6p21.2, 6q23-25, 8q24, 8p, 10q). On occasions the same locus has been linked with different forms of epilepsy, and on other occasions one form of epilepsy has been shown to be linked to several loci.
Assuntos
Epilepsia/genética , Encéfalo/fisiopatologia , Aberrações Cromossômicas/genética , Transtornos Cromossômicos , Epilepsia/classificação , Epilepsia/fisiopatologia , Expressão Gênica/genética , Ligação Genética/genética , Predisposição Genética para Doença , Humanos , FenótipoRESUMO
OBJECTIVE: To perform linkage analysis between the Short Tandem Repeats (STR) microsatellite markers D19S923, D19S929, D19S22, which are in strong genetic linkage to Notch3 gene in order to contrast the hypothesis that the vascular hereditary dementia phenotype described in a multigenerational extended pedigree from Colombia correspond to CADASIL (Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy). Even we know that using techniques as the Single Strand Conformational Polymorphisms (SSCP) could determine mutations in Notch3, the rationality of this approach is that intronic variations could not be defined and that we are interested in determine if some forms of the clinical presentation and its phenotypic variability make part of CADASIL. INTRODUCTION: The CADASIL phenotype is caused by mutations in the Notch3 gene. Clinical features of CADASIL are: 1. Recurrent cerebra-vascular episodes; 2. Migraine history; 3. History of transitory ischemic attack and, 4. Behavior changes and dementia. MATERIAL AND METHODS: By using SIMLINK we showed that the extended genealogy had the enough power to detect significant LOD (logarithm of oods) score values when Notch3 was considered the disorder cause. Linkage analysis was carried out by using parametric and non parametrical methods. The Elston-Stewart general method was used as the parametrical analysis and the sib pair method as the non-parametrical one. We perform simulations changing the affection status codification by including as affected or not including those individuals with migraine. Furthermore, in order to detect the stability of the results, we changed the penetrance values, the genetic frequencies on both, the marker loci and the affection locus. RESULTS: The maximum pair-wise LOD score was 2.04 which was detected at the marker D19S23 with q= 0.11cM. This distance correspond exactly with the Notch3 location. That is 100 times more probable that there is linkage that there is not. In other words this probability could be explained as if the phenotype correspond to CADASIL than to other vascular dementia. The non parametric results were compatibles with the parametric ones. When the migraine symptom was considered as a part of the affected status, the LOD score values showed not linkage. CONCLUSIONS: The results of the linkage analysis to these STR microsatellite markers suggest that the vascular hereditary dementia phenotype described in this family correspond to CADASIL caused by a polymorphism on the Notch3 gene. On the contrary, these same results suggest that the migraine phenotype is not a part of the progressive dementia.
Assuntos
CADASIL/genética , Ligação Genética , Proteínas Proto-Oncogênicas/genética , Receptores de Superfície Celular/genética , CADASIL/fisiopatologia , Colômbia , Humanos , Escore Lod , Repetições de Microssatélites , Fenótipo , Polimorfismo Genético , Receptor Notch3 , Receptores NotchRESUMO
INTRODUCTION: Linkage analyses provide strong evidence of how genetic factors influence epilepsy, due to the fact that they involve the determination of the cosegregation of specific marker alleles with epilepsy within families. AIMS: Our aim was to determine whether there was some kind of propensity to develop generalised idiopathic epilepsy (GIE) in the 15q22.1-q25.1 region in an extended multigenerational family from the Paisa de Antioquia community, which is a genetic isolate located in Colombia that segregates for GIE and has a strong capacity to detect linkage. PATIENTS AND METHODS: We selected a family containing a number of individuals suffering from epilepsy who visited the Antioquia Neurological Institute. Each affected individual had to have been diagnosed by a neurologist as suffering from non-myoclonic idiopathic epilepsy or from partial idiopathic epilepsy. All patients suspected of suffering from idiopathic epilepsy were submitted to video monitoring in order to characterise seizures electroencephalographically. RESULTS: Of the 106 individuals in this family who were included in the family tree, 76 were genotyped; 15 of them suffered from generalised clonic tonic seizures and six were considered as being possibly affected. Lod score results were significantly negative for all the markers in relation to each of the models under consideration. CONCLUSIONS: The possibility of the genes that code for the a-3, a-5 and b-4 subunits of the neuronal nicotinic acetylcholine receptor (CHRNA3, CHRNA5 and CHRNB4) situated in the 15q region being responsible for the familial aggregation of GIE in this family, as has been suggested in previous studies in other families, was ruled out.
Assuntos
Cromossomos Humanos Par 15 , Epilepsia/genética , Ligação Genética , Predisposição Genética para Doença , Colômbia , Eletroencefalografia , Epilepsia/diagnóstico , Epilepsia/fisiopatologia , Humanos , Escore Lod , Linhagem , Receptores Nicotínicos/genéticaRESUMO
INTRODUCTION: Myasthenia gravis (MG), considered the commonest of all the illnesses that affect neuromuscular transmission, is a disorder in which the autoimmune system attacks the post synaptic acetylcholine receptor proteins in the end plate terminal; it is characterised by weakness and skeletal muscle fatigue, with no anomalies in reflexes, sensitivity or coordination. Epidemiological indicators, such as incidence and prevalence, are not known in Colombia. AIMS. To determine the prevalence of MG among the inhabitants of Antioquia, through the use of the capture recapture method. PATIENTS AND METHODS: The capture recapture method was used for two sources, the Instituto Neurológico de Antioquia and the Hospital Universitario San Vicente de Pa l, which are the most important institutions for the diagnosis of neurological diseases in Antioquia. MG prevalence was calculated using the following formula: p= n/N 105. We examined the data from the period between 1 July 1995 and 30 June 2000 with the aim of identifying subjects who fitted the profile of MG sufferers. RESULTS: General MG prevalence in Antioquia was 27.7 cases per million inhabitants (CI 95%= 23.2 32.2). The male/female ratio was 1:3.77. CONCLUSIONS: The estimated prevalence of MG is lower than that reported in United States and other temperate regions, where it varies between 60 and 150 cases per million. The prevalence of MG is low in Antioquia, as in other tropical areas
Assuntos
Miastenia Gravis/epidemiologia , Adulto , Idade de Início , Área Programática de Saúde , Colômbia/epidemiologia , Feminino , Humanos , Incidência , Masculino , PrevalênciaRESUMO
INTRODUCTION: In extended and multigenerational pedigrees, the idiopathic epilepsy phenotype shows an extreme variability. OBJECTIVE: The range of idiopathic epilepsy onset age in multigenerational pedigrees was studied in order to determine if genetic anticipation play a role in the heredity of Idiopathic Epilepsies. PATIENTS AND METHODS: We compare the seizures onset age among relative-pairs of (parents-children, grandfathers-grandsons and nephew uncles). The mean onset age was compared using the Wilcoxon sign-rank paired-sample non-parametrical test to determine whether or not significant differences over > 0 exist, which refutes the null hypothesis of not anticipation. 84 pairs of relatives were taken from 72 extended multigenerational pedigrees. RESULTS: The onset age of idiopathic epilepsy of the pairs showed a difference significantly > 0, which confirm the existence of intergenerational differences. This difference has a tendency to decrease in age which each successive generation. This difference occur in all relative pairs and therefore contradicts the ascertainment bias described by Penrose. CONCLUSIONS: The results outline the existence of unstable mutations (those produced by a nucleotidic variable number of tandem repeats) as a probable explanation of the susceptibility to develop some forms of idiopathic epilepsy.
Assuntos
Epilepsia/genética , Feminino , Predisposição Genética para Doença , Humanos , Masculino , Inquéritos e QuestionáriosRESUMO
INTRODUCTION: Linkage analyses enable us to identify the loci that bestow susceptibility to certain diseases which are assumed to have a genetic aetiology by determining the cosegregation of alleles of specific markers within families. AIMS: The aim of this study was to determine whether there is generalised idiopathic epilepsy (GIE) susceptibility in the 8q22.1 -q24.23, 16p13.3 and 21q22.3 regions within an extended multigenerational family belonging to the Paisa community in Antioquia, a genetic isolate located in Colombia segregating for GIE with a strong capacity for detecting linkage. PATIENTS AND METHODS: A family with a number of individuals affected by idiopathic epilepsy who visited the Instituto Neurológico de Antioquia was selected for study. An affected individual was required to have been diagnosed by a neurologist as suffering from non-myoclonic idiopathic epilepsy or partial idiopathic epilepsy. All patients suspected of suffering from idiopathic epilepsy were submitted to video monitoring in order to characterise the seizures electroencephalographically. RESULTS: Of the 106 individuals in this family that were included in the family tree, 76 were genotyped, 15 of whom were affected by generalised clonic tonic seizures and six were considered to be possibly affected. Results of the lod score were significantly negative for all the markers in relation to each model that was considered. CONCLUSIONS: The possibility of the genes located in the 8q22.1 -q24.23, 16p13.3 and 21q22.3 regions being responsible for the familial aggregation of GIE in this family was ruled out, which is in accordance with claims made in previous studies conducted on other families.
Assuntos
Epilepsia/genética , Ligação Genética , Adolescente , Adulto , Criança , Pré-Escolar , Cromossomos Humanos Par 16 , Cromossomos Humanos Par 21 , Cromossomos Humanos Par 8 , Colômbia , Eletroencefalografia , Epilepsia/classificação , Epilepsia/diagnóstico , Epilepsia/fisiopatologia , Família , Feminino , Marcadores Genéticos , Genótipo , Humanos , Lactente , Escore Lod , Masculino , LinhagemRESUMO
INTRODUCTION AND OBJECTIVE: In order to elucidate the genetic and environmental components involved in the susceptibility to develop attention deficit hyperactivity disorder (ADHD), a complex segregation analysis on nuclear families (n = 53) ascertained from affected probands belonging to Medellín, in the Antioquian State, Colombia, was performed. METHODS AND RESULTS: Models of cohort effect (non-inheritance), multifactorial, recessive major gene, non-major gene component and non-transmission of major gene were rejected. Contrarily, dominant and codominant major gene models and non-multifactorial component could not be rejected. Thus, the better model fitting the data was that of the major gene (dominant/codominant). This major gene explains more than 99.99% of the ADHD phenotypic variance (value of heritability in the mixed model equal to 0.007%), which permit to assume a low aport of the environmental component to the phenotype ADHD. Gene frequency of the major gene was 3% in the general population of Antioquia and its penetrance was closed to 30%. CONCLUSION: Some cautions and aspects related to the bias of the interview and diagnosis of the parents are discussed.
Assuntos
Transtorno do Deficit de Atenção com Hiperatividade/genética , Transtorno do Deficit de Atenção com Hiperatividade/diagnóstico , Criança , Pré-Escolar , Estudos de Coortes , Cultura , Humanos , Penetrância , Fenótipo , Escalas de Graduação Psiquiátrica , EspanhaRESUMO
In attempt to identify the possible role of mayor genes, multifactorial inheritance, and cohort effects in the susceptibility to idiopathic epilepsy with generalized tonic clonic seizures of the awakening type (GTCS), complex segregation analysis was performed in 196 nuclear families ascertained through affected with probands with idiopathic epilepsy with GTCS belonging to the Paisa community of Antioquia (Colombia). Models postulating no transmission, single mayor locus (dominant and recessive) only, and multifactorial component only, were rejected. The models postulating no polygenic component to transmission, and no transmission of the major effect were also rejected. Thus far, complex segregation analysis suggested that a major autosomal codominant allele together with a multifactorial component (mixed model) best explains clustering of idiopathic epilepsy with GTCS in families of the Paisa community. The deficit of transmission of heterozygotes (0.17) is compatible with the existence of epistasis acting on a major gene whose frequency was estimated to be 0.0211. Its transmission variance accounts for 81% of the susceptibility to idiopathic epilepsy with GTCS. The complementary variance (19%) is due to polygenic component.
Assuntos
Epilepsia Tônico-Clônica/genética , Modelos Genéticos , Vigília , Adolescente , Adulto , Alelos , Criança , Pré-Escolar , Colômbia , Eletroencefalografia , Epilepsia Tônico-Clônica/diagnóstico , Feminino , Genes/genética , Humanos , Lactente , Recém-Nascido , MasculinoRESUMO
INTRODUCTION: Multiple sclerosis (MS) is the commonest demyelinating condition of the nervous system. It is characterized by numerous demyelinating areas or plaques of demyelination which are found dispersed throughout the nervous system. It has been shown that MS is less frequent in tropical regions than in subtropical regions. In Latin America particularly, there are some studies which show this phenomenon. However, in Colombia no studies of prevalence of MS have been done. OBJECTIVE: To determine the prevalence of multiple sclerosis in five provinces of Colombia (Antioquia, Caldas, Santander, Risaralda and Bolivar). PATIENTS AND METHODS: The capture-recapture method was used for two sources to determine the number of cases defined on the criteria of Poser et al seen between July 1995 and June 2000. RESULTS: The prevalence (cases of MS per 100,000 inhabitants) varied between 1.48 in Antioquia (95% CI 1.12; 1.78) and 4.98 in Risaralda (95% CI 3.52; 6.43). Seventy two percent were women. The regions included in this study represented 25% of the population of Colombia. CONCLUSIONS: There is a low prevalence of MS which is as expected in tropical areas. Persons with MS in these regions may be very useful in the study of other factors involved in the aetiology of MS (genetic). The capture-recapture method is an excellent tool for carrying out prevalence studies since it is cheap and requires little time.
Assuntos
Esclerose Múltipla/epidemiologia , Colômbia/epidemiologia , Estudos Transversais , Projetos de Pesquisa Epidemiológica , Geografia , Humanos , Prevalência , Clima TropicalRESUMO
INTRODUCTION: The BASC is a multidimensional approach to evaluate the child behavior and it has been validated on the diagnosis of ADD/+H in North American children. OBJECTIVE: Validating BASC-PRS 6-11 on the diagnosis of ADD/+H. PATIENTS AND METHODS: We selected 25 male DSM IV-ADD/+H (combined type), 6 to 11-years-old children, and 25 age, gender, and socioeconomic status matched controls. Mean ages of both groups 8.16 (1.5), schooling of controls 2.64 (1.4), and cases 2.6 (1.9). RESULTS: On the Clinical Scale ADD/+H children had significant (Anova p < 0.01) higher scores in hyperactivity, conduct problems, and attention problems. On the Adaptive Scale only significant differences on social skills and leadership were found, with lower score in the ADD/+H group. A crosstab analysis between group code and each rating variable transformed into categorical (0 and 1) variable, cut-off point = 85 percentile, found that the case children's parents qualified as clinically in higher risk the variables attention problems (OR = 24.4; 95% CI = 4.5-130), conduct problems (OR = 9.0; 95% CI = 1.7-46.9) and hyperactivity (OR = 6.8; 95% CI = 1.6-28.5) (p < 0.01). A discriminant analysis selected attention problems as discriminant function (p < 0.0001). Classification capability 84% for each group. CONCLUSION: Our results proved the validity of the BASC-PRS 6-11 questionnaire for the screening diagnosis of ADD/+H children in a Spanish speaking population.
Assuntos
Transtorno do Deficit de Atenção com Hiperatividade/diagnóstico , Pais/psicologia , Inquéritos e Questionários , Adulto , Transtorno do Deficit de Atenção com Hiperatividade/psicologia , Criança , Transtornos do Comportamento Infantil/diagnóstico , Transtornos do Comportamento Infantil/etiologia , Transtornos do Comportamento Infantil/psicologia , Feminino , Humanos , Masculino , Relações Pais-FilhoRESUMO
OBJECTIVE AND METHODS: We have analyzed a set of multigenerational extended pedigrees ascertained from affected cases of idiopathic epilepsy in the Antioquian Neurologic Institute. All pedigrees show familial aggregation of several forms of non myoclonic idiopathic epilepsy. In a recent paper, we have demonstrated that generalized idiopathic epilepsy of the awakening type is better explained by the existence of a major gene. In this paper, we have explored by simulation techniques the usefulness of the bigger pedigrees for linkage analysis. By using simlink and taking into account the parameters of the major gene, we have estimated that total power of three families is approximately 100 million times favoring the linkage detection. RESULTS AND CONCLUSIONS: These analyses suggest that the major gene accounting by the susceptibility to develop generalized idiopathic epilepsy of the awakening type could be localized by typifying affected families belonging to the Paisa community from Antioquia, Colombia (Acta Neurol Colomb 1997; 13: 69-75).
Assuntos
Epilepsia Generalizada/epidemiologia , Epilepsia Generalizada/genética , Triagem de Portadores Genéticos , Ligação Genética/genética , Modelos Genéticos , Família Multigênica/genética , Adolescente , Encéfalo/diagnóstico por imagem , Criança , Pré-Escolar , Colômbia/epidemiologia , Eletroencefalografia , Epilepsia Generalizada/diagnóstico , Feminino , Testes Genéticos , Humanos , Lactente , Recém-Nascido , Masculino , Linhagem , Fenótipo , Tomografia Computadorizada por Raios XRESUMO
OBJECTIVE AND METHODS: An experimental study about the predictions from the multifactorial threshold model created by Falconer is presented, assuming that this model may explain the genetic mechanisms underlying the family aggregation of idiopathic epilepsies. RESULTS: We failed to confirm the following predictions from the falconer model: decreased prevalence of disease in relatives, proportional to decreased family links, and the order of birth effect. An heredity greater than 100% was calculated which is concordant with the presence of at least a locus with a major gen affect. CONCLUSION: Our results reject the multifactorial threshold effect and suggest the presence of a major gen or Mendelian effect. An analysis of complex segregation is suggested for future studies.
Assuntos
Epilepsia/genética , Adolescente , Adulto , Distribuição por Idade , Idade de Início , Criança , Progressão da Doença , Epilepsia/diagnóstico , Epilepsia/epidemiologia , Feminino , Humanos , Masculino , Prevalência , Distribuição por SexoRESUMO
INTRODUCTION AND OBJECTIVE: Discrimination and quantification of the environmental and genetic components involved in developing multiple sclerosis (MS) have not been made. In order to discriminate these components we have ascertained affected individuals by MS belonging to the Paisa community from Antioquia, Colombia, a state localized in the tropical area of South America, to detect eventual linkage disequilibrium to HLA, locus DQ alpha, which could demonstrate the relevance of the genetic component. DEVELOPMENT: A contingence analysis among case-control HLA DQ alpha genotype distributions, by using Monte Carlo resampling method to solve small number sample, showed that there are significant differences between the two groups. We observe that HLA DQ alpha 1.1, 1.2 allele frequencies were higher in the cases than in the controls. Also, there was significant HLA DQ alpha 3 allele lower frequency (p < 0.05) in the cases than in the controls. CONCLUSIONS: Similar results have been described in other Caucasian populations living in non tropical areas. Before results could indicate that the Caucasoid populations genetic component implied in the susceptibility to MS have remained in Paisa community, whether the environmental component, being meaningful to develop MS.
Assuntos
Antígenos HLA-DQ/genética , Homeostase/genética , Esclerose Múltipla/epidemiologia , Esclerose Múltipla/genética , Adulto , Alelos , Encéfalo/patologia , Estudos de Casos e Controles , Área Programática de Saúde , Colômbia/epidemiologia , Potenciais Evocados/fisiologia , Feminino , Ligação Genética , Humanos , Espectroscopia de Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Esclerose Múltipla/diagnósticoRESUMO
INTRODUCTION: Behavioral Assessment System for Children (BASC) has demonstrated to be useful in the diagnosis of Attention Deficit Disorder (ADD). PATIENTS AND METHODS: A randomized sample of 120 children, 6 to 11-year-old, participants from the school of the city of Medellín, Colombia, was selected. The sample was stratified by sex and two socioeconomic status (SES). Parents were asked to answer the BASC Parent Rating Scale (PRS) 6-11, authorized Spanish version. RESULTS: Cronbach's alpha coefficient was 0.85 for the clinical scale (9 items). It was 0.75 for the Adaptive Scale (3 items). A scale designed with 4 items to assess ADD (hyperactivity, attention problems, aggression, and conduct problems) showed an alpha coefficient of 0.82. Male children scored significantly higher than female (ANOVA, p < 0.05) in hyperactivity, conduct problems, and atypicality. Children from low SES scored significantly higher than children of high SES on the most of clinical measures (p < 0.05) and lower on the three adaptive measures. Cluster analysis selecting six clusters found a prevalence of 61.6% for normal male children. In the total sample there were a 4% at risk of DDA type II (inattentive) and 14% at risk of DDA type I (combined). CONCLUSIONS: BASC PRS (6-11) showed reliability and validity to assessing the behavior in Spanish speaking Colombian children.
Assuntos
Transtorno do Deficit de Atenção com Hiperatividade/diagnóstico , Transtornos do Comportamento Infantil/diagnóstico , Pais , Inquéritos e Questionários , Criança , Colômbia , Feminino , Humanos , Masculino , Reprodutibilidade dos TestesRESUMO
Association between the major histocompatibility complex (MHC) and the susceptibility/resistance to acquire Chagas' disease has been largely demonstrated. To study the role of candidate genes in this susceptibility/resistance to Chagas, we designed a population-genetic-based case-control approach (chagasic n = 104 and controls n = 60) and tested the presence of genotype and linkage disequilibrium on microsatellite loci establishing specific landmarks for the MHC, interleukin (IL)-2, IL-2Rbeta chain, IL-4, IL-10, and natural resistance-associated mactophage protein 1 (NRAMP1). After demonstrating no genetic stratification among cases and controls (F(st) were not different from 0), we found significant allelic differences among chagasic patients and controls at microsatellite locus D6S291 (MHC) and at the microsatellite pointing out the IL-10. At the MHC, we found significant differences between patients and controls in Hardy-Weinberg equilibrium-expected genotype proportions. Additionally, MHC II-locus-inferred haplotypes in chagasic patients exhibited strong significant departures from the expected proportions predicted by the second Mendelian law. The linkage disequilibrium pattern at MHC involves a region of approximately 10 cM. These results replicate previous analyses and suggest that presence of epistasis between MHC with humoral systems, such as IL-10, could be underlying the susceptibility/resistance to Chagas' disease.