Trastorno por déficit de atención e hiperactividad en niños aymara: primera aproximación clínica / Attention deficit hyperactivity disorder in Aymara children

Background: The assessment of Attentional Deficit Hyperactivity Disorder (ADHD) among ethnic groups may reveal environmental or cultural variables that influence the appearance of this disorder. Aim: To assess the presence and characteristics of ADHD in two communities of the inland Arica valleys (Azapa and Lluta), where the Aymara population predominates. Material and Methods: Startingfrom a screening based on the Conner's test, we evaluated 79 children aged 8 to 13 years. Sixty children were of Aymara origin and 19 children were of non-Aymara origin. Twenty Aymara and 9 non-Aymara children had ADHD. They were compared with a group of patients from Santiago, Chile (110 children) that were previously assessed. Results: Patientsfrom Azapa/Lluta displayed similar characteristics to those from Santiago. However the former had significantly less psychiatric comorbidities than the latter. On the other hand, the non-Aymara subgroup of Azapa/ Lluta displayed an increased rate of comorbidities and was exclusively of the combined subtype, although their sample size is too small to draw strong conclusions. Conclusions: Although we cannot dismiss biological variables, the importance of family values and the respect to authorities may be protective factors for ADHD, associated to Aymara culture. Our findings suggest that the clinical characteristics of ADHD are not uniform among ethnic groups and cultures. The relative contribution of environmental and genetic factors in this variability remain to be determined.

Riesgo de déficit atencional/hiperactividad en escolares Aymara, Rapa-Nui y de Santiago de Chile: Posible contribución de polimorfismos genéticos del sistema dopaminérgico / Risk of attention deficit/hyperactivity disorder in Aymara and Rapa-Nui school children: Association with dopaminergic system polymorphisms

Background: Attention deficit/hyperactivity disorder (ADHD) is a common, highly heritable neurobiological disorder of childhood onset, characterized by hyperactivity, impulsiveness or inattentiveness. Aim: To search for differences in risk for ADHD and its components among Chilean native and mixed populations and to look forpossible associations with dopamine receptor D4 (DRD4) and dopamine transporter 1 (DAT1) polymorphisms. Material and Methods: School teachers were requested to complete the Conners test, which uses DSM-IV criteria, to screen for ADHD risk among Aymara and Rapa-Nui students. Results: Rapa-Nui children from Easter Island had the highest risk of hyperactivity/impulsiveness. Aymara children from the Arica-Parinacota Region had lower scores. Although inattentiveness scores had lower differences between groups, overall ADHD score differences among studied populations were highly significant. DRD4 and DAT1 alleles had a heterogeneous distribution. Easter islanders had more divergent frequencies, mostprobably as a result of separate migration routes utilized at different timeperiods during the colonization of America and Polynesia. Conclusions: The comparison of ADHD risk parameters between Rapa-Nui and Aymara children showed marked differences. Allele distri-bution of dopamine polymorphisms in Easter Island was also significantly different from northern Chile, due probably to different colonization histories. These findings suggest that higher ADHD risk scores in Easter Island children may be linked to the presence of different DRD4 alleles.