Familial hypercholesterolemia in Brazil.

The Brazilian population has heterogeneous ethnic origins and is unevenly distributed in a country of continental dimensions. In addition to the Portuguese colonists until the end of the World War II Brazil received almost 5 million immigrants who settled mainly in the south and southeast. This features of the Brazilian population have two important consequences for the inherited diseases that are associated with an ethnic background: their frequencies are different in various regions of the country reflecting a variety of ethnic origins and variable degrees of admixtures. There was no report about the molecular basis of hypercholesterolemia in Brazil until our report in 1996 that the Lebanese allele is the most common cause of the disease in our country: 10 out of the 30 families were of Arab origin, and the Lebanese allele was detected in 9 of the 10 unrelated families of Arab origin. In addition, the abnormal gene is associated with the same haplotype at the LDL-R locus in all but one family, suggesting single origin for this mutation. Recently we described seven mutations in exons 4, 7, 12 and 14 and a new mutation in exon 15. In another region of our state, eight mutation already described and seven new mutations were described and interesting no common mutations were find. We can conclude that the complex history and structure of the Brazilian population, which was formed by the contribution of a large number of ethnic components that are in a state of increasing miscegenation, is reflected in the frequency and regional distribution of the more common hereditary diseases.