Clinico-Metabolic Profile of Neurometabolic Disorders of Children in a Tertiary Care Hospital of Bangladesh

Background: Neurometabolic disorders are inborn errors of metabolism with neurological manifestations. They are individually rare but as a group have a significant burden. They constitute 4.9% of genetic cause of moderate and severe mental retardation.

Aims and objective: To explore clinical & metabolic profile of various forms of childhood Neurometabolic disorders.

Methods: A hospital based retrospective study was conducted at Department of Pediatric Neurology, Bangabandhu Sheikh Mujib Medical University, and Dhaka from January 2016 to December 2020. Total 59 suspected children of Neurometabolic disorders (NMD), who admitted in hospital during the study period, were included. Among them 41 cases of NMD were diagnoses confirmed on the basis of clinical suspicion, biochemical test, and neuroimaging study and in few cases molecular genetics investigations.

Results: Among 59 suspected cases, total 41 patients were diagnosed as Neurometabolic disorders. Most of the (63.2%) patients were within 0-3 years age. Male patients (70.73%) were outnumbered than female (29.26%). Male: Female ratio were 2.4:1. More than half of patients 25(60.90%) had parental consanguinity followed by Sib death 7 (17.07%), Prematurity 11 (26.82%). Common Neurometabolic disorders were aminoacidopathy 14 (34.14%) and lysosomal storage disorders 15 (36.58%) followed by mitochondrial disorders 5(12.19%), Urea cycle disorders 3(7.31%), CHO metabolism disorders 5(2.43%), Peroxisomal disorders 3(7.31%). Among aminoacidopathy, Organic acidamia 4(9.72%), MSUD 3(7.31%), PKU 2(4.86%), Gluteric Aciduria 3(7.31%), and Biotinidase deficiency disorder 1(2.43%) were common disorders. Among lysosomal storage disorders, mucopolysaccaridosis 4(9.72%) and metachromatic leukodystrophy 8(19.44%) were most common disorders. Common presentations were developmental delay 37(90.24%), developmental regression 21(51.21%), hypotonia 29(70.73) and seizures 26(63.41%). Neuroimaging changes found in about three fourth (80.49%) of cases. About 26.82% cases presented with white matter hyper intensity followed by basal ganglia hyper intensity (19.51%) and cerebral atrophy (14.63%). Abnormally high ammonia and lactate found in 6(14.63%) and 10(24.40%) cases respectively followed by Positive urinary ketones 8 (19.51%).

Conclusions: Neurometabolic disorders are not uncommon. The commonest neurometabolic disorders were aminoaciduria and lysosomal storage disease in our study. Among aminoacid disorders, Organic acidamia, MSUD, Glutaric aciduria and in lysosomal storage disorders metachromatic leukodystrophy & Mucopolysaccharoidosis were common disorders. Neuroimaging changes were found in about three- forth cases in this study.