Diagnosis of autism spectrum disorders (ASDs) may be made easier by the discovery of a biochemical marker for ASD. In fact, the development of a rapid, noninvasive screening test for ASDs may be based on high levels of aspartic acid in urine, Cleveland Clinic researchers have shown.
A subset of 69 individuals with ASDs and with or without macrocephaly in the presence or absence of PTEN gene mutations was evaluated in the study. Genetic screening through PTEN sequencing, physiologic measurements, and amino- and organic-acid analyses of urine and plasma samples were performed.
Six (27%) of 22 individuals with ASD and macrocephaly were found to have germline PTEN mutations. No individuals in the macrocephalic group, with or without PTEN mutations, had any common biochemical abnormalities.
When evaluated collectively, however, high levels of aspartic acid (an amino acid) in the urine were found in 54 (87%) of 62 participants.
The Centers for Disease Control and Prevention has estimated that ASDs may be occurring in some form in 1 in 88 children. These research findings on a diagnostic biochemical marker for ASDs are promising, given the significant variability in ASDs that may render the alternative of genetic screening impractical due to the labor required.
Hobert JA, Embacher R, Mester JL, Frazier TW 2nd, Eng C. Biochemical screening and PTEN mutation analysis in individuals with autism spectrum disorders and macrocephaly. Eur J Hum Genet. 2013. Epub ahead of print.