Dementia in Fragile X-associated Tremor/Ataxia Syndrome / Demência na síndrome de tremor-ataxia associada ao X-Frágil

Fragile X-associated tremor/ataxia syndrome (FXTAS) is a cause of movement disorders and cognitive decline which has probably been underdiagnosed, especially if its prevalence proves similar to those of progressive supranuclear palsy and amyotrophic lateral sclerosis. We report a case of a 74-year-old man who presented with action tremor, gait ataxia and forgetfulness. There was a family history of tremor and dementia, and one of the patient?s grandsons was mentally deficient. Neuropsychological evaluation disclosed a frontal network syndrome. MRI showed hyperintensity of both middle cerebellar peduncles, a major diagnostic hallmark of FXTAS. Genetic testing revealed premutation of the FMR1 gene with an expanded (CGG)90 repeat. The diagnosis of FXTAS is important for genetic counseling because the daughters of the affected individuals are at high risk of having offspring with fragile X syndrome. Tremors and cognitive decline should raise the diagnostic hypothesis of FXTAS, which MRI may subsequently reinforce, while the detection of the FMR1 premutation can confirm the condition.

A síndrome de tremor-ataxia associada ao X-frágil (FXTAS) é uma causa de distúrbios do movimento e de declínio cognitivo que provavelmente tem sido subdiagnosticada, especialmente se a sua prevalência for realmente similar às da paralisia supranuclear progressiva e esclerose lateral amiotrófica. Relatamos um caso de um homem de 74 anos que se apresentou com tremor de ação, ataxia de marcha e esquecimento. Havia história familiar de tremor e de demência e um de seus netos era mentalmente deficiente. A avaliação neuropsicológica demonstrou uma síndrome frontal. A ressonância magnética (RM) revelou hiperintensidade de ambos os pedúnculos cerebelares médios, um critério maior para o diagnóstico de FXTAS. Os testes genéticos confirmaram a presença da pré-mutação do gene FMR1, com uma repetição (CGG)90. O diagnóstico de FXTAS é importante para o aconselhamento genético porque as filhas dos indivíduos afetados tem alto risco de ter uma criança com síndrome do X-frágil. A presença de tremores e declínio cognitivo deve levantar a hipótese diagnóstica de FXTAS, que poderá ser reforçada pela RM e confirmada pela presença da pré-mutação do gene FMR1.

Genetic and clinical aspects of neurofibromatosis type 1: study of a large sample of affected brazilian individuals / Aspectos genéticos e clínicos da neurofibromatose tipo 1: estudo de uma grande amostra de brasileiros portadores

Here we describe the results obtained in a sample of 209 Brazilian patients affected by neurofibromatosis type 1 (NF1 or von Recklinghausen´s disease). The phenotypic description of the sample included the determination of average values and frequency estimates of 25 measurements, signs, and symptoms according to their occurrence (familial or isolated) and to sex and age. The following parameters were estimated from our sample: proportion of familial and isolated cases, sex-ratio, segregation rate, penetrance value, fitness value, and birth order effect. We studied also the pattern of distribution of skin pigmentation spots and neurofibromas and determined the conditional probabilities favoring the diagnosis of NF1 of primary and secondary signs and symptoms presented by adults suspected of having the condition.

Homosexuality and inbreeding

Overt homosexuals were interviewed in an attempt to fmd out if the consanguinity rate of their parents was greater than that of the couples in the general population. We found parental consanguinity in five among 175 male homosexuals and one in 106 homosexual women, the rate of consanguineous individuals (2.2 per cent) did not differ significantly from that of a control sample of 695 university students of both sexes, among whom 2.9 per cent had consanguineous parents. Our data do not conform to the suggestion, made by Keff and Freire-Maia (Rev. BrasiL Genet. 6: 177-180, 1983), that parental consanguinity is greater in male homosexuals than in the general population.

Comparative analysis of dermatoglyphic indices used for diagnosis of Down's syndrome

No presente trabalho comparamos, usando técnicas padronizadas de análise discriminante, quatro métodos que säo comumente empregados para o diagnóstico dermatoglífico da síndrome de Down (mongolismo): säo eles os métodos propostos por Walker (1957), Beckman et al. (1965, Greyerz-Gloor et al. 91969) e Reed et al. (1970). A conclusäo principal do trabalho é de que qualquer um desses quatro métodos pode ser usado indiferentemente num paciente com suspeita clínica de síndrome de Down, uma vez que a capacidade discrinatória deles é sob o ponto de vista prático e estatístico a mesma. Apresentamos também tabelas de probabilidades para uso imediato que fornecem as chances condicionaus de afecçäo por síndrome de Down como funçäo dos escores observados dos quatro índices