Genetics, History and Historical Genetics of Machado-Joseph Disease (MJD)
02:00pm to 04:00pm

First described as an Azorean disease, MJD was then found in mainland Portugal and, later, in many other countries. It is, in fact, the most common autosomal dominant ataxia in the world. The MJD gene was mapped in 1993 and the causative mutation identified in 1994. Since then, we have been studying the origins of the MJD mutations and their possible routes of diffusion. A worldwide study pointed to two main ancestral haplotypes. The Machado haplotype is fairly recent (~1,000 years) and limited mainly to São Miguel, central mainland, and their descendants in Canada, USA and Brazil. The Joseph haplotype is older (~7,000 years), present in Flores and north-eastern Portugal, and the one prevalent in the vast majority of affected populations. Our study of two large Australian Aboriginal kindreds reinforced the hypothesis of an Asian origin of the original mutation.


The seminar is free, and all are welcome (including members of the public) without needing to book a place.

Language: English



Jorge Sequeiros
IBMC - i3S and ICBAS; Univ. Porto, Portugal

MD (1975) and PhD (1990), Univ. Porto. Post-doctoral fellow (1982-85) at Johns Hopkins Hosp., Baltimore. Specialist in Internal Medicine and in Medical Genetics (1987). Full Professor of Medical Genetics; Director, MSc on Genetic Counselling, ICBAS, Univ. Porto. Research group leader, UnIGENe; and Director, Centre for Predictive and Preventive Genetics; IBMC, i3S, Univ. Porto. Former President: College of Medical Genetics; Portuguese Human Genetics Society; Ethics Commission of the Univ. Porto; National Medical Genetics Commission; Ataxia Research Group (WFN). Former member: National Council of Bioethics; and PPPC, Education Committee and Board (of the ESHG), among several others.