RP-HPLC-ESI-MS profile of naturally occurring salivary peptides of subjects with autistic spectrum disorder [ASD; N = 27: 12 with diagnosis of autism, 1 with diagnosis of Asperger, 14 with diagnosis of pervasive developmental disorders not otherwise specified (PDD-NOS)] was compared to that of age-matched controls with the goal of identifying differences that could turn out to become hallmarks of at least a subgroup of ASD individuals.
Phosphorylation level of four specific salivary phospho-peptides, namely statherin, histatin 1 (both, p < 0.0001) and acidic proline-rich proteins (both entire and truncated isoforms) (p < 0.005) was found significantly lower in autistic patients, with hypo-phosphorylation of at least one peptide observed in 18 ASD subjects (66%).
Developmental scale assessment (Griffith or WISC-R) carried out on 14 ASD subjects highlighted a normal to borderline cognitive development in 10 of them, all included in the hypo-phosphorylated group. Phosphorylation of salivary peptides involves a Golgi casein kinase common to many organs and tissues, CNS included, whose expression seems to be synchronized during fetal development.
Hypo-phosphorylation of salivary peptides suggests potential asynchronies in the phosphorylation of other secretory proteins, which could be relevant in central nervous system development either during embryonic development or in early infancy.
These results suggest that analysis of salivary phospho-peptides might help to discriminate a considerable subgroup of autistic spectrum disorder patients.
Source: Journal of Proteome Research, Nov 7, 2008:7 (12), pp 5327–5332 [E-pub ahead of Print] PMID: 18989956, by Castagnola M, Messana I, Inzitari R, Fanali C, Cabras T, Morelli A, Pecoraro AM, Neri G, Torrioli MG, Gurrieri F. Istituto di Biochimica e Biochimica Clinica, Istituto di Genetica Medica, Istituto di Neuropsichiatria Infantile, Facolta di Medicina, Universita Cattolica, Rome, Italy, Istituto Scientifico Internazionale "Paolo VI" and Istituto per la Chimica del Riconoscimento Molecolare, Consiglio Nazionale delle Ricerche, Rome, Italy; Dipartimento di Scienze Applicate ai Biosistemi, Sezione di Biochimica e Biologia Molecolare, Universita di Cagliari, Cagliari, Italy [E-mail: email@example.com]