RESUMEN
OBJECTIVES: Hereditary Gingival Fibromatosis (HGF) is a rare benign fibrous lesion of the gingival tissues presumably caused by single gene defects. The aim of this study was to identify the genetic defect leading to HGF in an extended pedigree. MATERIALS AND METHODS: We report the clinical features and genetic analysis of a family affected by HGF. A total of 17 subjects were assessed clinically and had blood samples taken for DNA extraction. Multipoint parametric linkage analysis was performed to identify the possible chromosomal location responsible for HGF in this family. RESULTS: Presence of severe HGF associated with tooth impaction was confirmed for seven members of this three-generation family. Linkage analysis revealed that loci on chromosomes 7, 10, 13, 15, 16, 17, 19 and 20 were linked to this trait. Previously found mutations in the SOS1 and GINGF loci were therefore excluded by this analysis. CONCLUSIONS: This study brings further evidence for genetic heterogeneity of HGF and points towards the existence of different, not-yet-identified genes linked to this condition.
Asunto(s)
Fibromatosis Gingival/genética , Heterogeneidad Genética , Ligamiento Genético/genética , Adolescente , Mapeo Cromosómico , Cromosomas Humanos Par 10/genética , Cromosomas Humanos Par 13/genética , Cromosomas Humanos Par 15/genética , Cromosomas Humanos Par 16/genética , Cromosomas Humanos Par 17/genética , Cromosomas Humanos Par 19/genética , Cromosomas Humanos Par 20/genética , Cromosomas Humanos Par 7/genética , Femenino , Sitios Genéticos/genética , Humanos , Escala de Lod , Masculino , Linaje , Diente Impactado/genéticaRESUMEN
Attention-Deficit/Hyperactivity Disorder (ADHD) has a very high heritability (0.8), suggesting that about 80% of phenotypic variance is due to genetic factors. We used the integration of statistical and functional approaches to discover a novel gene that contributes to ADHD. For our statistical approach, we started with a linkage study based on large multigenerational families in a population isolate, followed by fine mapping of targeted regions using a family-based design. Family- and population-based association studies in five samples from disparate regions of the world were used for replication. Brain imaging studies were performed to evaluate gene function. The linkage study discovered a genome region harbored in the Latrophilin 3 gene (LPHN3). In the world-wide samples (total n=6360, with 2627 ADHD cases and 2531 controls) statistical association of LPHN3 and ADHD was confirmed. Functional studies revealed that LPHN3 variants are expressed in key brain regions related to attention and activity, affect metabolism in neural circuits implicated in ADHD, and are associated with response to stimulant medication. Linkage and replicated association of ADHD with a novel non-candidate gene (LPHN3) provide new insights into the genetics, neurobiology, and treatment of ADHD.