Citrin缺陷导致的生长发育落后和血脂异常：一种新的临床表现型

Failure to thrive and dyslipidemia caused by citrin deficiency:a novel clinical phenotype

Citrin缺陷病(citrin deficiency,CD)已报道两种临床表现型,一种是成人发病瓜氨酸血症Ⅱ型(CTLN2),另一种是citrin缺陷导致的新生儿肝内胆汁淤积症(NICCD)。该文报道1例以生长发育落后和血脂异常为主要临床表现的男性CD幼儿。患儿1岁6月时体重和身长均低于相应WHO体格测量百分位表上的第3百分位数,同时血生化分析发现甘油三酯和总胆固醇水平显著增高,伴高密度脂蛋白胆固醇降低。病史询问发现患儿1岁后有难以纠正的厌食米饭而嗜食鱼肉的饮食习惯。偏食倾向2岁后更明显,血氨基酸分析显示瓜氨酸和苏氨酸轻度增高,于是该患儿在2岁5月时被怀疑为CD。按患儿饮食嗜好自然喂养之后,其生长发育落后逐渐改善,体重在3岁时恢复到第3百分位数以上,血脂逐渐恢复正常。SLC25A13突变分析表明患儿是851del4的纯合子。据此,患儿被确诊为CD。4岁7月时的饮食调查表明患儿有典型的低碳水化合物和高蛋白饮食倾向——厌食米饭,而嗜好海鲜、肉类、蛋类和奶类。该患儿主要临床表现为生长发育落后和血脂异常,为一种不同于NICCD和CTLN2的新的CD表现型。

Two clinical phenotypes for citrin deficiency （CD） have been reported. One is adult-onset citrullinemia type II （CTLN2） and another is neonatal intrahepatie eholestasis caused by citrin deficiency （NICCD）. A child with CD and who had failure to thrive （FTT） and dyslipidemia as main clinical manifestations is reported here. Both the weight- and length-for-age at 18 months dropped below the 3rd percentile in the corresponding WHO anthropometry percentile charts, while blood biochemical analysis revealed dramatically increased triglyceride and total cholesterol, together with reduced HDL-eholesterol. Inquiries revealed his aversion to rice and fondness for fish since the age of one year, a peculiar habit which could not be corrected. Since the age of two years, the peculiar diet became more obvious, and slightly increased eitrulline and threonine levels were detected on blood amino acid analysis. At the age of two years and five months he was suspected to have CD. Since then, he has been fed in accordance with his own food preferences, and FTT improved gradually, with weight-for-age, in particular, recovering beyond the 3rd percentile at three years of age, and dyslipidemia was also ameliorated gradually. SLC25A13 gene analysis revealed a homozygote of 851de14, and CD was thus confirmed. Diet survey at four years and seven months revealed a fondness for high-protein and low-carbohydrate foods, such as seafood, meat, eggs and milk. This child presented with FTT and dyslipidemia as main clinical manifestatioris and this was a novel CD phenotype different from NICCD and CTLN2.