Objective: In this study, we investigate the influence of internal migration within Brazil on the prevalence of Huntington’s disease in the state of Amazonas.

Background: The state of Amazonas, located in the northern region of Brazil, exhibits a demographic profile characterized by indigenous and African influence alongside European admixture. Historically, the region has attracted migrants from various parts of Brazil, mainly from Pará (north of Brazil) and northeastern states. These migrations, driven by economic opportunities and social factors, have led to a complex intermingling of genetic backgrounds within the Amazonian population.

Method: We studied 22 families affected by HD in the state of Amazonas and identified a total of 51 genetically confirmed cases. We trace the origin of the oldest affected member of each family, within Brazil or abroad. We analized the genetic characteristics of families according to their geographic origin.

Results: We identified 22 patients (43.1%) originated from families with roots in northeastern states. Another 22 cases (43.1%) were from the North of Brazil, 1 (1.9%) patient from Venezuela and 6 patients (11.7%) of unknown origin.

The paternal transmission is predominant among patients from the Amazonas state, with 8 out of 13 cases exhibiting this mode of inheritance. Similarly, patients from Ceará show a higher prevalence of paternal transmission, with 10 out of 15 cases following this pattern. The other states display a more balanced distribution between paternal and maternal transmission. Regarding the size of CAG expansions, patients from the Amazonas state exhibit the largest average expansion size at 50.9 repeats, followed by patients from Pará (47.6 repeats), Ceará (46.4 repeats), and Pernambuco (46.2 repeats). (FIGURE 1).

Conclusion: This study highlights the impact of internal migration on the distribution of Huntington’s disease within Brazilwith a significant contribution from other states to the prevalence of Huntington’s disease in Amazonas.

The influx of migrants from northeastern states, where HD prevalence may be higher due to genetic and environmental factors, has likely contributed to the increased occurrence of the disease in Amazonas. This underscores the importance of considering local demographic factors and historical migration patterns in understanding disease epidemiology.

Figure 1.

« Back to 2024 International Congress

MDS Abstracts - https://www.mdsabstracts.org/abstract/genetic-migration-dynamics-unraveling-the-influence-of-internal-migration-on-huntingtons-disease-prevalence-in-the-amazonas-state/