喂养困难伴运动发育落后8个月、眼球震颤4个月

Feeding difficulty and developmental delay for 8 months and nystagmus for 4 months in an infant

摘要:

芳香族L-氨基酸脱羧酶（AADC）缺乏症是一种罕见的常染色体隐性遗传病，为AADC缺乏导致的先天性神经递质生物合成的代谢紊乱。主要表现为肌张力低下、动眼危象、自主神经功能紊乱、发育落后等，目前尚无成熟的治疗方法。该文报道1例表现为发育落后、肌张力低下、动眼危象的男性患儿，代谢性疾病基因筛查发现多巴胺脱羧酶（DDC）基因外显子区域存在新的复合杂合突变：c.1063dupA（p.I355fs）、c.250A > C（p.S84R），血滤纸片3-O-甲基多巴明显升高，因此确诊为AADC缺乏症。给予多巴胺受体激动剂盐酸普拉克索、儿茶酚-O-甲基转移酶抑制剂恩他卡朋联合维生素B₆治疗，患儿肌张力低下、眼睑下垂、动眼危象得到轻度改善。临床医师应提高对AADC缺乏症这一罕见病的识别能力，对肌张力低下、运动落后、动眼危象的患儿应考虑到此病，以期予以早期诊断及治疗，并为有需要的患儿父母提供优生遗传咨询及产前诊断。

Abstract:

Objective Aromatic L-amino acid decarboxylase (AADC) deficiency is a rare autosomal recessive hereditary disease and is a congenital metabolic disorder of neurotransmitter biosynthesis. It is mainly manifested as hypotonia, oculogyric crisis, autonomic dysfunction, and developmental delay. This article reports a boy manifested as delayed motor development, hypotonia, and oculogyric crisis. Gene screening for metabolic disorders revealed new compound heterozygous mutations, c.1063dupA (p.I355fs) and c.250A > C (p.S84R), in the exon of DDC gene. The boy had a significant increase in 3-O-methyldopa as measured by dried blood spot. Therefore, he was diagnosed with AADC deficiency. After treatment with the dopamine receptor agonist pramipexole dihydrochloride, the catechol-O-methyltransferase inhibitor entacapone, and vitamin B₆, the boy showed mild improvements in hypotonia, blepharoptosis, and oculogyric crisis. Clinical physicians should enhance their ability for identifying AADC deficiency, so as to facilitate early diagnosis and treatment of this disorder. Genetic counseling for birth health and prenatal diagnosis should be performed for parents in need.