Adenylosuccinate lyase (ADSL) and infantile autism: Absence of previously reported point mutation

Autism is a heterogeneous neuropsychiatric syndrome of unknown etiology. There is evidence that a deficiency in the enzyme adenylosuccinate lyase (ADSL), essential for de novo purine biosynthesis, could be involved in the pathogenesis of certain cases, A point mutation in the ADSL gene, resulting in a predicted serine-to-proline substitution and conferring structural instability to the mutant enzyme, has been reported previously in 3 affected siblings. In order to determine the prevalence of the mutation, we PCR-amplified the exon spanning the site of this mutation from the genomic DNA of patients fulfilling DSM-III-R criteria for autistic disorder. None of the 119 patients tested were found to have this mutation, Furthermore, on preliminary screening using single-strand conformation polymorphism (SSCP), no novel mutations were detected in the coding sequence of four ADSL exons, spanning approximately 50% of the cDNA. In light of these findings, it appears that mutations in the ADSL gene represent a distinctly uncommon cause of autism. (C) 1995 Wiley-Liss, Inc.