However, they possess an important risk factor for FRAXopathies, leading to 40 % of men (10, 23) and 16 % of women to present FXTAS (10, 24) characterized by distal tremors similar to that of parkinson's and an ataxic gait; 20 % of female carriers develop FXPOI (10, 25) and present an absence of menstruation before 40 years of age, including menstrual cycle disorders and decreased reproduction.
Genetic counseling for male carriers of the premutation consists in informing that the probability of having male carrier sons is 0 % since the X chromosome in males is of maternal origin, but the probability of having female carrier daughters is 100 % and these could have children affected by the syndrome (36); information should also be given about the risk of developing FXTAS.
These patients had no reproductive expectations at the time of the diagnosis; none of them presented ovarian failure before the age of 40, distal tremors or gait alterations at the time of the evaluation; each one was given information about the risk of presenting FXTAS in the future.
La toxicidad por RNA induce a la muerte neuronal temprana en cultivo, por ende los portadores de la premutacion estan en riesgo de desarrollar desordenes del envejecimiento como FXTAS y FXPOI (11).
El FXTAS es un desorden neurodegenerativo progresivo (11), de inicio tardio, que ocurre entre los portadores de la premutacion, caracterizada por deficits neurologicos que incluyen temblor progresivo de intencion, ataxia cerebelar, parkinsonismo, neuropatias y disfuncion autonomica (34-36).
Of these, 2 239 unrelated individuals (887 white, 959 black, 211 mixed ancestry and 182 Indian) had a suspected diagnosis of FXS or ID of unknown cause (1 961 males and 278 females), 430 were extended family members referred for FXS carrier or diagnostic testing (mothers of affected individuals, siblings and other at-risk second and third-degree relatives), four requested POI or FXTAS testing, and 17 were prenatal samples (obtained by chorionic villus sampling (CVS) or amniocentesis) from at-risk pregnancies.
A PM was found in 1/3 females tested, and one male referred for FXTAS tested negative.
18] They would be predicted to be at risk of POI and FXTAS, but the exact risk is unclear.
Although there is no specific treatment for FXTAS
, FMR1-associated premature ovarian failure, or the psychiatric and musculoskeletal manifestations of Fragile X premutation, establishing the correct diagnosis might prevent unnecessary additional testing and procedures.
Additionally, physicians are finding a high level of heart failure and hypertension in men with FXTAS, he said.
One study of 25 men showed the mean age of onset of FXTAS was 62 years.
Expansions of >200 CGG are associated with FXS, whereas more modest expansions can contribute to FXTAS