Molecular Mechanisms of Dementia

Le résumé fourni par la source

The possibility that the loss of mutant alle- les is balanced by the transition of larger nor- mal ones into the lower DM range, which are more frequently found in DM males, should also be considered.Although our data are at variance with the recent report of Chakraborty et al" for normal subjects, it is still unknown whether the mechanisms responsible for segregation distortion are the same for DM alleles in the normal range compared to full scale ex- panded ones.The preferential transmission of larger alleles could be modulated by as yet unidentified cis and trans acting genetic elements, or could be a direct consequence of the CTG repeat number, affecting gamete or zygote viability.The recent observations that the expanded allele is preferentially transmit- ted in male meiosis in other conditions caused by dynamic expansions, such as dentatorubral-pallidoluysian atrophy and MJD,'4 15 are more suggestive of a direct con- sequence of the CTG repeat number in these conditions, at least for full scale expanded alleles.In summary, results from the present study confirm that the issue of meiotic drive and segregation distortion is still controversial and may vary in different populations.Further studies will be important to shed more light on this fascinating question.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.