ABSTRACT
Autism spectrum disorders (ASD) are characterized by a broad range in clinical presentation. Although a definite genetic cause has not yet been fully demonstrated, family based studies suggest that a multigenic pattern may be responsible for susceptibility, but most results are conflicting and have yet to be replicated. The purpose of this investigation was to analyze the linkage of the human leukocyte antigen (HLA) and the human serotonin transporter coding (5-HTTLPR) genes with ASD in a group of 37 families of Sardinian ethnicity in insular Italy. In 50% of these families, ASD is linked to HLA, and in the other 50% it is linked to 5-HTTLPR polymorphic genes; in other words, linkage to one or the other was evident in all cases. Despite a very homogenous genetic pattern being generally reported for Sardinians, the linkage observed with HLA and 5-HTTLPR genetic regions indicated a statistically defined heterogeneity (p=0.002). No allelic HLA or 5-HTTLPR polymorphisms were specifically associated with ASD, suggesting these loci as markers of other genes mapped in their close proximity that may be more directly involved and thus may merit further analytical studies.
Subject(s)
Autistic Disorder/epidemiology , Autistic Disorder/genetics , Ethnicity/genetics , HLA-DR Antigens/genetics , Polymorphism, Genetic , Serotonin Plasma Membrane Transport Proteins/genetics , Adolescent , Child , Child, Preschool , Female , Genetic Linkage , HLA-DRB1 Chains , Humans , Italy/epidemiology , Italy/ethnology , Male , Molecular EpidemiologyABSTRACT
Classic Kaposi's sarcoma (CKS) is a multifocal vascular mesenchymal tumour of unknown origin. Human herpesvirus 8 (HHV8) is now considered to be strongly involved, as a necessary co-factor, though insufficient for development of the disease. Additional identified risk factors include environmental factors, personal habits and genetic susceptibility, with different loci suspected of being risk factors for CKS. Since various human leukocyte antigen (HLA) patterns have been suggested as potential host-related co-factors, the distribution of these alleles was studied in 41 CKS patients, 285 geographically-matched healthy controls (HC) and 17 HHV8-positive controls. Molecular typing of HLA was performed using the polymerase chain reaction sequence-specific primer method (SSP-PCR). Frequency distribution was evaluated by the Chi-squared test with Yates' correction. Odds ratios (OR) and respective 95% confidence limits (CI) were calculated. A significantly higher frequency of HLA-DRB1*13 was observed among the CKS patients (20.7%) compared to the HC (9.8%) (p<0.01; OR: 2.32; 95%CI: 1.21-4.41). Overall, these results indicated that HLA-DRB1*13 may play a role in the development of CKS, while HLA-DQB1*0604 allele involvement occurs in linkage disequilibrium with HLA-DRB1*13. To our knowledge, this is the first study documenting an HLA-DRB1 and -DQB1 loci association with CKS development in the mainland Italian population.