Serotonin transporter gene polymorphisms and hyperserotonemia in autistic disorder

• Previous studies have provided conflicting evidence regarding the association of the serotonin transporter (5-HTT) gene with autism. Two polymorphisms have been identified in the human 5-HTT gene, a VNTR in intron 21 and a functional deletion/insertion in the promoter region (5-HTTLPR) with short and long variants.2 Positive associations of the 5-HTTLPR polymorphism with autism have been reported by two family-based studies, but one found preferential transmission of the short allele3 and the other of the long allele.4 Two subsequent studies failed to find evidence of transmission disequilibrium at the 5-HTTLPR locus.5,6 These conflicting results could be due to heterogeneity of clinical samples with regard to serotonin (5-HT) blood levels, which have been found to be elevated in some autistic subjects.7–9 Thus, we examined the association of the 5-HTTLPR and VNTR polymorphisms of the 5-HTT gene with autism, and we investigated the relationship between 5-HTT variants and whole-blood 5-HT. The transmission/disequilibrium test (TDT) revealed no linkage disequilibrium at either loci in a sample of 96 families comprising 43 trios and 53 sib pairs. Furthermore, no significant relationship between 5-HT blood levels and 5-HTT gene polymorphisms was found. Our results suggest that the 5-HTT gene is unlikely to play a major role as a susceptibility factor in autism.

Ämnesord

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin -- Psykiatri (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine -- Psychiatry (hsv//eng)

Nyckelord

Adolescent

Adult

Alleles

Autistic Disorder

Blood

Genetics

Blood Platelets

Metabolism

Carrier Proteins

Genetics

Physiology

Child

Child

Preschool

Female

Genetic Heterogeneity

Genetic Predisposition to Disease

Haplotypes

Genetics

Humans

Introns

Genetics

Linkage Disequilibrium

Male

Membrane Glycoproteins

Genetics

Physiology

Membrane Transport Proteins

Minisatellite Repeats

Mutagenesis

Insertional

Nerve Tissue Proteins

Polymorphism

Genetic

Risk Factors

Sequence Deletion

Serotonin

Blood

Serotonin Plasma Membrane Transport Proteins

Publikations- och innehållstyp

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art (ämneskategori)