Diagnosis and long-term follow-up of 4-hydroxy butyrate aciduria in 9 cases / 中华实用儿科临床杂志

ABSTRACT

Objective To study the clinical and laboratory diagnosis and follow-up of 4-hydroxy butyrate aciduria in children.Methods From June 2012 to July 2017,9 cases in Tianjin Children's Hospital were analyzed.According to their clinical features,multidimensional analysis was pedormed by using head magnetic resonance imaging (MRI),urine gas chromatography-mass spectrometry (GC/MS) semi-quantitative testing and gene mutation analysis of ALDH5A1.Results The onset age of the 9 cases was less than 1 year old,and all had psychomotor retardation,in which 4 cases with epileptic seizures,1 case with consciousness disturbance and 1 case with involuntary movement.All the cases underwent head MRI and 4 cases showed bilateral symmetry pallidal lesions,including 1 case with symmetry abnormality of the midbrain cerebral peduncle,1 case with encephalomalacia in left temporal cortex and 4 cases with widening of the ventricle and extracerebral space.By the urine GC/MS semi-quantitative testing,all 9 the cases showed increasing 4-hydroxy butyric acid and by the ALDH5A1 gene mutation analysis,all 9 the cases were detected with gene mutation (3 cases belonging to c.1568C ＞ T homozygous mutation,1 case belonging to c.839T ＞ G homozygous mutation and the other 5 cases belonging to compound heterozygous mutation,which included c.691G ＞ A,c.1568C ＞T;c.1383_2delA,c.1568C ＞ T;c.527G ＞ A,c.691G ＞ A;c.904G ＞ A,c.1022C ＞ A;c.398_399delA,c.638G ＞ T).Nine cases were given symptomatic treatment,and 4 cases with epileptic seizures were given antiepileptic drugs.During the follow-up of the above 9 cases,1 case died of status epilepticus,1 case had been under control for 5 years,and 2 cases were effectively treated.Psychomotor retardation was improved in varying degrees in 8 cases.Involuntarymovement disappeared in 1 case while 2 cases still showed increasing 4-hydroxy butyric acid by means of urine GC/MS semi-quantitative testing.Conclusions Most of 4-hydroxy butyrate aciduria occurs within 1 year old,with psychomotor development as the first manifestation,which can be associated with epilepsy.The head MRI is characterized by a symmetrical Globus pallid abnormal signal.Urine GC/MS shows an increase in 4-hydroxy butyrate,which is the basis for biochemical diagnosis of the disease.Its accumulation in the body mainly damages the central nervous system.ALDH5A1 is a disease-causing gene,in which c.1568C ＞ T site has a high mutation frequency,and it is speculated that this site may be a hot spot mutation in Chinese children.Patients with epilepsy may die from status epilepticus and may be used as a clinical indicator to judge the severity of the disease.There is no specific treatment,and the patients combined with epilepsy can be treated with anti-epileptic drugs.Valproic acid should be avoided as it can aggravate the condition.