汉族儿童N—乙酰化代谢表型分布及其与21—三体综合征和假肥大性肌营养不良症相关性研究

目的 以咖啡因为代谢探针，研究汉族儿童Ｎ－乙酰化代谢表型分布规律及其与２１－三体综合征（ＤＳ）和假肥大性肌营养不良症（ＤＭＤ）相关性。方法 根据参试者尿中咖啡因代谢物５－乙酰氨基－６－甲酰氨基－３－甲基尿嘧啶（ＡＦＭＵ）和甲磺嘌呤（１Ｘ）峰高比的对数值（１ｇＡＦＭＵ／１Ｘ）绘制频率分布直方图，寻找区分快、慢乙酰化代谢表型的截点，确定患儿和健康儿童的Ｎ－乙酰化代谢表型分布。结果 正常儿童乙酰化代谢表型分布直方图呈双态性，截点明显，为 ０．２５（ｌｇＡＦＭＵ／１Ｘ），慢乙酰化代谢表型个体为１６．９％，而 ＤＳ和ＤＭＤ患儿则分别为４１．９％和５０％（ｘ２分别为８．２８７和１１．３８７，Ｐ＜０．０５）。男、女和＞６岁与≤６岁儿童快、慢乙酰化代谢表型分布差异无显著性。结论 汉族儿童乙酰化代谢表型分布呈多态性，与成人相似。年龄和性别对结果无显著影响。

Distribution of N-acetylate phenotype in chinese children and its relationship with down''s syndrome and duchenne muscular dystrophy

The distribution of N-acetylate phenotype in Chinese children and its relationship with Down' s syndrome(DS) and Duchenne muscular dystrophy (DMD) was investigated. Methods Thirty-one subjects with Down' s syndrome, 18 with Duchemne muscular dystrophy and 154 healthy children were acetylate-phenotyped with caffeine as a probe drug.Urine samples were collected 2 hours after administration of 60-100 ml of 10 mg/100 ml caffeine-spiked coca cola and analyzed by high performance liquid chromatography (HPLC) . The LgAFMU/ IX of peak hight ratio was used to construct the frequence histogram and probit plot and to assese slow and fast acetylator staus both in the healthy and the DS/ DMD children. Results The range of Ig AFMU/ IX in healthy children was 0.45-1.86, and in those with DS and DMD was 0.15-1.56 and 0.15-0.38 respectively. The ratio of 0.25 [Ig(AFMU/1X)] was sellected as a cut-off and used to separate slow and fast acetylators. Slow acetylators in children with DS accounted for 41.9% (13/ 31) whi le with DMD 50% (9/ 18), significantly higher than 16.9% of healthy children (X2 = 8.287, P< 0. 005 and X2=11.367, P< 0.005 respectively) .Conclusions The acetylate status is polymorphic in Chinese healthy children. Slow acetylators of children with DS or DMD were more than those of healthy children. Age and sex had no significant influence to acetylate status.