Análisis de ligamiento genético del síndrome de Gilles de la Tourette en una familia colombiana

Introduction. Gilles de la Tourette Syndrome (GTS) is a cronic neuropsychiatric disorder characterized by fonic and motor tics. Although its physiopathologic bases are unknown, the cortical-striatal-talamic-cortical circuit has been studied. The association of GTS with attention deficit hyperactivity disorder (ADHD), obsessive-compulsive disorder (OCD), motors tics (MT) or phonics tics (PT), the high family aggregation, and the concordance studies in twins, support the genetics bases of this disorder. Currently, GTS is accepted as a complex disorder and the associated disorders could be alternative expressions of the same syndrome. Aim. To evaluate genetic linkage to 2p11, 6p24, 11q23, 20q13 and 21q22 regions in an Antioquian family with enough power to detect linkage. Patients and methods. With the Linkage program and using autosomic dominant, recessive and additive inheritance models, the genetic linkage was calculated; two phenotypic spectra was considered: one broad spectrum including affected individuals with GTS, ADHD, OCD, MT, and PT, and a narrow spectrum with only GTS. Results. The most probable inheritance pattern for a susceptibility locus in GTS and its associated disorders in this family is autosomic additive. The presence of a locus involved in GTS in the 2p11 region has been rejected. Conclusion. The linkage values for D20S1085 and D6S477 markers are suggestive and therefore it is not possible reject that these markers will be in linkage disequilibrium with genes involved in the GTS, ADHD, OCD, MT, and PT etiology.