日本科学家发现一种可能与嗜睡病有关的基因变体，有望据此找到治疗这种疾病的方法。
日本研究人员通过分析国内222名嗜睡病患者和389名正常人的基因组，发现患者体内一种基因变体出现频率相当高。他们把研究结果发表在英国《自然遗传学》杂志上。
这种基因位于疑与睡眠紊乱相关的CPT1B 基因和CHKB基因之间。前者控制一种调节睡眠的酶，后者与睡眠周期有关。
东京大学人类遗传学系教授德永胜士表示：“45％的嗜睡病患者携带这种基因变体，正常人这一比例为30％。”
他说，找到这一变体为专家寻求嗜睡病治疗方法开辟了方向。
嗜睡病是一种睡眠紊乱症，特征是白天睡眠过多、视力减退、肌无力等。美国人和欧洲人发病率是两千五百分之一，日本人发病率至少是他们的4倍。（生物谷Bioon.com）
生物谷推荐原始出处：
Nature Genetics (28 Sep 2008), doi: 10.1038/ng.231, Letters
Variant between CPT1B and CHKB associated with susceptibility to narcolepsy
Taku Miyagawa, Minae Kawashima, Nao Nishida, Jun Ohashi, Ryosuke Kimura, Akihiro Fujimoto, Mihoko Shimada, Shinichi Morishita, Takashi Shigeta, Ling Lin, Seung-Chul Hong, Juliette Faraco, Yoon-Kyung Shin, Jong-Hyun Jeong, Yuji Okazaki, Shoji Tsuji, Makoto Honda, Yutaka Honda, Emmanuel Mignot, Katsushi Tokunaga
Narcolepsy (hypocretin deficiency), a sleep disorder characterized by sleepiness, cataplexy and rapid eye movement (REM) sleep abnormalities, is tightly associated with HLA-DRB1*1501 (M17378) and HLA-DQB1*0602 (M20432). Susceptibility genes other than those in the HLA region are also likely involved. We conducted a genome-wide association study using 500K SNP microarrays in 222 Japanese individuals with narcolepsy and 389 Japanese controls, with replication of top hits in 159 Japanese individuals with narcolepsy and 190 Japanese controls, followed by the testing of 424 Koreans, 785 individuals of European descent and 184 African Americans. rs5770917, a SNP located between CPT1B and CHKB, was associated with narcolepsy in Japanese (rs5770917[C], odds ratio (OR) = 1.79, combined P = 4.4 10-7) and other ancestry groups (OR = 1.40, P = 0.02). Real-time quantitative PCR assays in white blood cells indicated decreased CPT1B and CHKB expression in subjects with the C allele, suggesting that a genetic variant regulating CPT1B or CHKB expression is associated with narcolepsy. Either of these genes is a plausible candidate, as CPT1B regulates -oxidation, a pathway involved in regulating theta frequency during REM sleep, and CHKB is an enzyme involved in the metabolism of choline, a precursor of the REM- and wake-regulating neurotransmitter acetylcholine.
