RESUMEN
This paper presents some of the results of our studies on two distinct groups of disorders: Muscular dystrophies and craniofacial conditions. Among the first, we focused on autosomal recessive (AR) limb-girdle muscular dystrophies (LGMD). To date, there are 8 known loci associated with AR LGMD (LGMD2A, LGMD2B to 2H). We were able to map 2 of these 8 genes through the analysis of large Brazilian families. We also classified 140 patients into one of the seven AR LGMD forms: LGMD2B is the mildest and a clear phenotype-genotype correlation was not observed in most of the cases. Molecular studies on craniofacial disorders have been recently initiated, as exemplified in the text with a discussion on craniosynostosis and cleft lip and/or palate (CL/P). The study of Brazilian patients with craniosynostosis caused by mutations in fibrobrast growth receptor genes (FGFR1-3) allowed us to identify some Apert and Pfeiffer patients with unusual mutations. In addition, about 10 percent of Brazilian patients with coronal synostosis seem to be due to a specific mutation within FGFR3. Finally, our molecular studies on CL/P patients excluded two genes (one, a transforming growth factor and the other involved in folate metabolism) as major candidates for this common malformation. Further studies are being conducted in all the disorder presented in this paper.