患儿,女,维吾尔族,11岁,初诊时头发黄而无光泽,皮肤白皙,智力发育严重障碍,言语发育严重滞后,步态不稳需由他人搀扶,肌张力增高,胆小,注意力不集中,身体及尿液中有强烈的鼠臭味。尿液三氯化铁试验呈强阳性。患儿无同胞兄妹,其父母身体健康,均无遗传病史。留取患儿及父母血液,分别测定血苯丙氨酸浓度,患儿为1260μmoL/L、父 Children, women, Uygur, 11 years old, newly diagnosed hair yellow and dull, fair complexion, mental retardation, speech development serious lag, unsteady gait need to be helped by others, increased muscle tone, timid, attention Not concentrated, the body and urine have a strong smell of rats. Urine ferric chloride test was strongly positive. Children without siblings siblings, their parents healthy, no genetic history. Children and their parents were collected from the blood, respectively, determination of plasma phenylalanine concentration, children with 1260μmoL / L, the parent