Contreras L Miranda, Luengo W Delgado, Zerpa N, Hernández J Chacín, Chávez C J, Ferrer S González
Laboratorio de Bioquímica Genética, Instituto de Genética Médica, Facultad de Medicina, Universidad del Zulia, Maracaibo, Venezuela.
An Pediatr (Barc). 2012 Mar;76(3):148-52. doi: 10.1016/j.anpedi.2011.09.020. Epub 2011 Nov 18.
Neuronal ceroid lipofuscinoses are a group of inherited autosomal recessive lysosomal diseases, most commonly found in infancy. These are neuropathologically characterised by accumulation of an autofluorescent lipopigment in neurons and other cells. This condition is clinically characterised by loss of motor and cognitive skills, lack of motor coordination, ataxia, progressive visual impairment, behavioural changes; seizures of difficult to manage seizures, particularly myoclonic, and premature death. Ten clinical forms have been described, one of which is late infantile where clinical signs begin between two and four years. The gene responsible for this disease is located at 11p15 locus, and the enzyme encoded by this gene is the tripeptidyl peptidase 1.
We standardised the technique for the enzymatic diagnosis of late infantile neuronal ceroid lipofuscinoses from dried blood on filter paper card in 76 healthy individuals adults and children in order to establish a normal range in the Venezuelan population. The tripeptidyl peptidase activity was also determined in 9 patients with a clinical diagnosis of late infantile neuronal ceroid lipofuscinoses.
Six of the samples showed activity lower than the lowest control value (0.11 to 0.45 nmol/spot) from healthy controls of infantile age, confirming the enzymatic diagnosis. Three of the 14 parent samples analysed showed values in the heterozygote ranges.
The enzymatic diagnosis of late infantile neuronal ceroid lipofuscinoses from dried blood on filter paper card is a rapid, easier, less expensive and accurate molecular diagnosis tool.
神经元蜡样脂褐质沉积症是一组常染色体隐性遗传的溶酶体疾病，多见于婴儿期。其神经病理学特征为神经元和其他细胞中自荧光脂色素的积累。该病症的临床特征为运动和认知技能丧失、运动协调能力缺乏、共济失调、进行性视力损害、行为改变、难以控制的癫痫发作，尤其是肌阵挛发作，以及过早死亡。已描述了十种临床类型，其中一种是晚期婴儿型，临床症状在两到四岁之间开始出现。导致这种疾病的基因位于11p15位点，该基因编码的酶是三肽基肽酶1。
我们对76名健康成人和儿童滤纸卡上干血中晚期婴儿型神经元蜡样脂褐质沉积症的酶诊断技术进行了标准化，以便确定委内瑞拉人群的正常范围。还对9例临床诊断为晚期婴儿型神经元蜡样脂褐质沉积症的患者测定了三肽基肽酶活性。
六个样本的活性低于婴儿期健康对照的最低对照值（0.11至0.45 nmol/斑点），证实了酶诊断。在分析的14个亲本样本中，有三个显示的值在杂合子范围内。
滤纸卡上干血中晚期婴儿型神经元蜡样脂褐质沉积症的酶诊断是一种快速、简便、成本较低且准确的分子诊断工具。
