Frecuencia del polimorfismo genético ACTN3 R577X y ECA I/D en atletas ciegos de fútbol 5 / Frequency of genetic polymorphism ACTN3 R577X and ACE I/D in blind athletes of 5-a-side football

RESUMEN: El objetivo de este estudio fue describir la frecuencia genotípica y alélica del ACTN3 R577X y ECA I/D en atletas ciegos de fútbol 5. Se incluyó una metodología descriptiva con una muestra de 63 deportistas ciegos (28,0±5,8 años), todos varones, de equipos de fútbol 5 de alto rendimiento. El polimorfismo se determinó mediante la reacción en cadena de la polimerasa en tiempo real (RT-PCR). La estadística fue descriptiva realizada a partir de las medidas de frecuencia de genotipos y alelos. La frecuencia genotípica de la ACTN3 en los deportistas presentó la siguiente distribución: el 28,6 % con genotipo RR, el 54 % con RX y el 17,4 % con XX y frecuencia alélica del 55,6 % para el alelo R y del 44,4 % para el alelo X. En cuanto a la ECA I/D, la frecuencia genotípica fue del 63,5 % para el genotipo ID, del 22,2 % para el DD y del 14,3 % para el II. La frecuencia alélica presentó prevalencia del alelo D con el 53,9 %. El estudio constató una predominancia de los genotipos y alelos representativos de las modalidades de fuerza y velocidad para ACTN3 R577X y ECA I/D de atletas de fútbol 5.

SUMMARY: The aim of this study was to describe the genotypic and allele frequency of ACTN3 R577X and ACE I/D in blind athletes of 5-a-side football performance. A descriptive methodology was included with a sample of 63 blind male athletes (28.0 ±5.8 years) of football teams with a 5-a-side performance rating. The polymorphism was determined by means by of real-time Polymerase Chain Reaction (rt-PCR). Statistics were descriptive based on the measures of frequency of genotypes and alleles. The genotypic frequency of ACTN3 by the athletes presented the following distribution: 28.6 % with RR genotype, 54 % with RX and 17.4 % XX and allele frequency of 55.6 % for the R allele and 44.4 % for the X allele. As for ACE I/D, the genotype frequency was 63.5 % for genotype ID, 22.2 % for DD and 14.3 % for II. The allele frequency showed a predominance of the D allele with 53.9 %. The study found for ACTN3 R577X and ACE I/ D of blind athletes of 5-a-side football, a predominance of genotypes and alleles representative of strength and speed modalities.

Molecular confirmation of the causes of inherited visual impairment in northern Pakistan

Families with inherited visual impairment were identified and examined from January 2000 to December 2005 and given a clinical diagnosis. Known genes and loci were screened for mutations or linkage at Institute of Ophthalmology and Neurosciences, University of Leeds, in order to provide molecular confirmation. Inherited retinal disease was the most common cause of inherited visual impairment in 38 of 57 families [66.6%] with Leber's congenital amaurosis, rod-cone dystrophy and cone-rod dystrophy being the most common diagnoses in 22, 8 and 3 families respectively. Anterior segment dysgenesis was diagnosed in 8 families [14%]. Mutations in known genes or linkage to known loci were identified in 23 of 57 families [40%]. All families had molecular confirmation of autosomal recessive inheritance or a pedigree consistent with this mode of inheritance, with evidence of first-cousin marriage. Knowledge of carrier status and genetic counseling may allow families to make an informed decision regarding marriage, and thus begin to plan a way of reducing the incidence of inherited visual impairment

Genetics and prevention of blindness / Genética e prevenção da cegueira

PURPOSE: To verify the perception of Brazilian ophthalmologists regarding the role played by Genetics in their routine medical activity and their conduct when dealing with patients, with hereditary diseases who need genetic counseling. METHODS: A cross-sectional survey was conducted by means of invitations to participate in an interview on this subject. The questionnaires were sent to 200 ophthalmologists who work in the area of Campinas, SP, Brazil. RESULTS: Among the 73 professionals who answered the questionnaire (36 percent), there was a high rate of positive answers (49-88 percent) concerning their knowledge of genetics and a low rate (10-33 percent) of use of this knowledge in their clinical practice. The frequency of genetic ophthalmopathies in clinical practice was relevant in the opinion of 68 percent of the interviewees; 92 percent indicated a relevant relationship between genetically determined ocular disorders and the prevention of blindness through detection, early treatment and genetic counseling. More extensive genetic knowledge was considered indispensable to 84 percent of the professionals, but 16 percent answered that it was irrelevant. CONCLUSIONS: Although these ophthalmologists have basic notions of genetics (88,0 percent) and are aware of its importance in the prevention of blindness, a great majority of Brazilian ophthalmologists have not acquired adequate knowledge of genetics and, in practice, rarely use its therapeutic and preventive potential.

OBJETIVO: Verificar a percepção de oftalmologistas brasileiros em relação à contribuição da Genética em sua atuação médica rotineira, bem como a sua conduta em face de portadores de doenças hereditárias que necessitem de aconselhamento genético MÉTODOS: Estudo transversal, em que duzentos oftalmologistas que atuam na região de Campinas, SP, Brasil (universidades e/ou clínicas particulares) foram convidados a participar de uma entrevista sobre o assunto. RESULTADOS: Aqueles que aceitaram o convite (36 por cento), enviaram um questionário respondido, via correio (n=73). A importância das oftalmopatias genéticas em relação a sua freqüência na clínica prática foi relevante na opinião de 68 por cento dos entrevistados e 92 por cento manifestaram sua opinião como sendo muito importante a relação das oftalmopatias genéticas e a prevenção à cegueira, por meio da detecção e tratamento precoces e aconselhamento genético. Quanto à opinião dos entrevistados sobre melhorar seus conhecimentos em genética, 84 por cento consideraram imprescindível, porém 16 por cento responderam que é irrelevante. CONCLUSÕES: De um modo geral, embora os oftalmologistas entrevistados tenham adquirido noções básicas de Genética (88 por cento) e estão conscientes de sua importância na prevenção da cegueira, os conhecimentos de genética da grande maioria dos oftalmologistas brasileiros são incompletos e, na prática, quase que inexplorados em seu potencial terapêutico e preventivo.

Congenital blindness: report of leber congenital amaurosis in a large Iranian Kindred

Leber congenital amaurosis [LCA] is a hereditary neonatal blindness. Congenital blindness is common among a specific branch of the Lore tribes in Kerman province, central Iran. This study was designed to identify all affected patients, construct a pedigree for obtaining the transmission pattern, establish definite diagnosis, and finally determine the genetic origin of the blindness among this tribe. Using several field studies, over a period of 2 years, and conducting interviews with senior members of the tribe, a total of 25 patients were identified. Electrophysiological tests and karyotyping were undertaken for appropriate cases. DNA samples collected from a group of affected individuals and their first-degree relatives were used to evaluate genetic linkage to a number of known loci on different chromosomes. Autosomal recessive pattern of inheritance and neonatal visual impairment without any noticeable eye lesions was documented. Infantile nystagmus, keratoconus, narrowing of retinal vessels, retinal degeneration, mild pigmentary retinopathy and electrophysiological investigations were consistent with LCA. Only one locus on 17p13.1 was consistent with linkage in this kindred. We made a large pedigree of LCA for the first time in Iran. Mutation screening of the responsible gene is currently in progress

Deficiência visual grave em populações do Nordeste do Brasil / Severe visual deficiency in the population of northeastern of Brazil

O presente estudo caracterizou principalmente fatores genéticos e epidemiológicos numa avaliação geral de portadores de Deficiência Visual Grave (DVG) de acordo com as recomendações da Organização Mundial de Saúde (OMS). A amostra foi constituida de 184 portadores de DVG de ambos os sexos na faixa etária de 3 a 54 anos de idade, oriundos dos Estados do Rio Grande do Norte, Paraíba e Pernambuco. A averiguação ocorreu no período de fevereiro de 1995 a fevereiro de 1996 em três instituições especializadas no atendimento de cegos, através de análise de prontuários, questionários, entrevistas e construção de heredogramas. Do total de portadores de DVG, 125 foram do sexo masculino e 59 do sexo feminino (razão de sexo: 2,1). a Principal idade de início de sinais ou sintomas da DVG variou de 0 a 5 anos de idade. O fenótipo racial predominante foi o caucasóide (85,85 por cento). A distribuição percentual das categorias etiológicas foi a seguinte: Categoria Genética (65,22 por cento), Categoria não-genética (25,00 por cento) e Categoria indeterminada (9,78 por cento). Os resultados revelam que o impacto dos fatores genéticos é expressivo na epidemiologia da Deficiência Visual Grave

Estudio genético en limitados visuales: rol del consejo genético / Genetical study of visual limmited: genetic counsil roll

Considerando que aproximadamente el 50% de los casos de ceguera infantil son de orden genético y además la tendencia en los limitados visuales a casarse entre ellos, el consejo genético es muy importante. Con este propósito, se investigan las causas de ceguera en 69 asistentes a la Escuela de la Corporación de Ayuda al Limitado Visual de Concepción. Con el objeto de clasificar y aclarar la etiología de su ceguera, pilar fundamental del consejo genético, se hace valoración dirigida de la historia clínica, antecedentes perinatales, pedigree y examen físico. Del total de limitados visuales, 33(47,8%) son de causa hereditaria; de éstos, 12(36,4%) tienen herencia autosómica dominante; 11(33,3%) autosómica recesiva; 2(6%) recesiva ligada al sexo, y 3(9,1%) probable herencia multifactorial. En 5 casos (15,2%) no se pudo precisar el mecanismo. En 8(11,6%) no se logró precisar etiología. Los 28(40,6%) casos restantes se deben a causa ambiental, siendo la mayoría de tipo postnatal. Se discute la importancia del consejo genético, tanto en el afectado como sus familiares, con la finalidad de evitar la recurrencia de cegueras previsibles