Page 113 - Genomic Medicine in Emerging Economies

102 CHAPTER 6: Neuropsy chiatric Genomics in Latin Americ a

Mental, neurological, and substance use disorders accounted for 258 mil-
lion DALYs in 2010, which was equivalent to 10.4% of total all-cause DALYs
(Murray et al., 2012; Whiteford et al., 2015). These disorders as a group
ranked as the third leading cause of DALYs, after cardiovascular and circula-
tory diseases, diarrhea, lower respiratory infections, meningitis, and other
common infectious diseases (Murray et al., 2012; Whiteford et al., 2015).
NPDs also accounted for 28.5% of global YLDs, making them the leading
cause of YLDs (Murray et al., 2012; Whiteford et al., 2015). The distribu-
tion of DALYs among NPDs is heterogeneous and depends mainly on the
economic profile of the population studied; for example, epilepsy ranks as
the 36th leading cause of DALYs globally; however, in some low to middle
income countries of Latin America and western sub-Saharan Africa, NPDs
rank as the 21th and 14th leading cause of DALYs, respectively (Murray
et al., 2012). Epilepsy also represents the second most disabling neurolog-
ical disorder (as measured in YLDs), only surpassed by migraine, and in
some Latin American countries it ranks as the ninth leading cause of YLDs
(Vos et al., 2012).
Several studies have been carried out in Latin America to estimate the prevalence
in the general population of selected NPDs (Table 6.1) (Burneo et al., 2005;
Cristiano et al., 2013; Guerra et al., 2009; Jimenez-Castro et al., 2011; Kisely
et al., 2017; Kohn et al., 2005; Kolar et al., 2016; Nitrini et al., 2009; Prince
et al., 2013; Pringsheim et al., 2014), highlighting the national and regional
importance of several NPDs of high epidemiological impact.

The population of Latin America and the Caribbean is composed of approxi-
mately 620 million people living in 26 countries, speaking two major lan-
guages, and sharing ancestral roots in America, Europe, and Africa (Adhikari
et al., 2016) (Fig. 6.1). The region is considered one of the most diverse in
the world, with an extensive variability in ancestries, ethnic groups, and races
(Li et al., 2008). The population of Latin America is the result of the mat-
ing of Native Americans with individuals from early migrations from Africa
and Europe and later waves of European and Asian migration (Adhikari
et al., 2016). Recent analyses from mestizo populations from seven countries
in Latin America showed evidence that the genetic origins of these populations
are composed mainly by European men and Native American women (Wang
et al., 2008). In this study, the Native American ancestry ranged from ∼20%
to ∼70% in Rio Grande do Sul and Salta, respectively (Wang et al., 2008). The
African ancestry is also variable and mostly low (<5%) and possibly related
to the intensity of slavery in each country (Wang et al., 2008). Considering
that Brazil had a long and intense history of slavery, the frequency of African
ancestry is much higher than the mean frequency found in other countries in
Latin America. The pooled ancestry frequency from African ancestry in Brazil
was 21% (Moura et al., 2015). However, unexpectedly, in a study involving 934