These results suggest a possible linkage between abnormal plasma chemistries, especially those related to the pro-opiomelanocortin system, and autistic symptoms.
Since autoimmune response involves immune activation, the plasma levels of interferon-alpha (IFN-alpha), interferon-gamma (IFN-gamma), interleukin-12 (IL-12), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), and soluble intercellular adhesion molecule-1 (sICAM-1) were measured in autistic patients and age-matched normal controls.
The convergence of GABRB3 as a positional and functional candidate along with the linkage-disequilibrium data suggests the need for further investigation of the role of GABRB3 or adjacent genes in autistic disorder.
Mice with null mutations of Hoxa1 or Hoxb1, two genes critical to hindbrain development, have phenotypic features frequently observed in autism, but no naturally occurring variants of either gene have been identified in mammals.
We have screened the families of the Collaborative Linkage Study of Autism for several markers spanning a candidate region covering approximately 2 Mb and including the Angelman syndrome gene (UBE3A) and a cluster of gamma-aminobutyric acid (GABA(A)) receptor subunit genes (GABRB3, GABRA5, and GABRG3).
We review the scanty literature data on the association of Cowden syndrome and autism and emphasize that the association of progressive macrocephaly and pervasive developmental disorder seems to be an indication for screening for PTEN mutations.