McKean C M
Arch Dis Child. 1971 Oct;46(249):608-15. doi: 10.1136/adc.46.249.608.
The long-term responses of 5 adolescent phenylketonuric patients to chemically-defined, synthetic diets with normal and low phenylalanine content were determined. The synthetic preparations were found capable of sustaining good health and rapid growth in this group of profoundly retarded, behaviourally disturbed patients over a 3½-year period without clinical or biochemical evidence of nutritional inadequacy. 4 of these patients who were treated for 6 months on a comparable diet, in which 80% of the phenylalanine was replaced by tyrosine, continued to show weight maintenance and height increases. There was no evidence of poor acceptability of the imbalanced diet, whether the blood phenylalanine concentrations were at phenylketonuric or treatment levels. The phenylalanine intake required to maintain blood phenylalanine concentrations of 3-5 mg/100 ml in these 4 patients was well below normal requirements, and ranged between 6·8 and 20·1 mg/kg per day. Predictably, the phenylalanine requirement varied with individual growth rates. All 4 treated patients had objective signs of improved central nervous system function during the six-month period on the phenylalanine-restricted diet. These electrophysiological and behavioural improvements were manifest after blood phenylalanine concentrations fell below 12 mg/100 ml in 3 cases and below 5 mg/100 ml in the fourth.
测定了5名青少年苯丙酮尿症患者对含正常和低苯丙氨酸含量的化学定义合成饮食的长期反应。结果发现，这些合成制剂能够在3年半的时间里，使这群严重发育迟缓、行为紊乱的患者保持健康并快速生长，且没有营养不足的临床或生化证据。其中4名患者接受了6个月的类似饮食治疗，饮食中80%的苯丙氨酸被酪氨酸替代，他们继续保持体重并增高。无论血液苯丙氨酸浓度处于苯丙酮尿症水平还是治疗水平，都没有证据表明这种不平衡饮食的可接受性差。这4名患者维持血液苯丙氨酸浓度在3 - 5mg/100ml所需的苯丙氨酸摄入量远低于正常需求，每天每公斤体重在6.8至20.1mg之间。可以预见，苯丙氨酸需求量随个体生长速度而变化。在接受苯丙氨酸限制饮食的6个月期间，所有4名接受治疗的患者都有中枢神经系统功能改善的客观迹象。在3例患者中，血液苯丙氨酸浓度降至12mg/100ml以下，在第4例患者中降至5mg/100ml以下后，出现了这些电生理和行为改善。
