Human narcolepsy susceptibility candidate genes analyzed by microarray, quantitative RT-PCR and distribution shown by in situ hybridization in mice.

n.t.; not tested, n.e.; no expression, n.c.; no coexpression in perifornical hypocretin area.probe set ID is from aAffymetrix, QRT-PCR probe ID is from Applied Biosystems, and All clones for in situ hybridization are IMAGE clones except where noted.Gene expression was compared between 6 narcolepsy and 8 control postmortem posterior hyptothalami (A and B Genechip). Narcolepsy candidate genes selected by statistical analysis of microarray data are listed at left, quantitative RT-PCR results are in the center, and results of in situ hybridization in mouse hypothalamus are at the right. As only downregulated genes were confirmed by RT-PCR studies, upregulated candidates are not shown. Genes labeled with ��validated�� were confirmed as narcolepsy related genes. Note that IGFBP3 is the only gene validated by QRT-PCR and showing a hypocretin-like distribution pattern. Some candidates showed uniform signal over the whole brain section, potentially indicating ubiquitous expression, but we regarded the staining as background and classified the gene as not expressed if no anatomical variation in staining level was observed.