Calcium and Magnesium Levels Are down Regulated in Nigerian Children with Autism Spectrum Disorder and Cerebral Palsy

Abstract

Autism Spectrum Disorders (ASDs) and Cerebral Palsy (CP) are amongst the leading neurodevelopmental disorders in children worldwide causing diminished quality of life. Unlike CP caused by brain damage affecting muscle tone, movement and motor skills, equivocal report of different genes with varying loci as genetic malformation and genetic modulation by environmental factors have been the focus of attention in the aetiology of ASD. This study investigated levels of toxic metal (Pb) and macro elements (Ca and Mg) in blood of children with ASD and CP in Nigeria. 8 and 18 Children (aged 2 - 12 years) clinically screened for features of ASD and CP respectively by pediatric neurologist using DMS-IV classification along with 15 age-matched neurologically healthy ones as controls were recruited. Plasma levels of Ca, Mg and Pb were determined in the children using Induction Coupled Plasma Mass Spectroscopy (ICP-MS). Results were analyzed using students t-test. The gender difference was not significant in the children (P = 0.216) while developmental milestones’ abnormalities (stable neck, sitting, crawling and walking) was significantly prevalent among CP children relative to ASD and normal children (P= 0.003, 0.003, 0.003 and 0.000 respectively); however, abnormality in talking was common in ASD and CP relative to normal children (P = 0.000). There was significant difference in educational background of ASD and CP parents relative to those of normal children (P = 0.025). Mean plasma calcium and magnesium levels was significantly reduced in children with ASD (7.90 ± 0.17 mg/dl, 2.44 ± 0.07 mg/dl) and CP (7.26 ± 0.31 mg/dl, 2.42 ± 0.08 mg/dl) in comparison to the controls (8.97 ± 0.20 mg/dl and 3.26 ± 0.16 mg/dl); (P < 0.001; P < 0.000 and P < 0.002; P < 0.000) respectively. However, mean lead levels in children with CP (10.38 ± 1.45 μg/dl) were significantly greater than in ASD (7.92 ± 1.30 μg/dl) and normal children (6.83 ± 0.72 μg/dl) (P < 0.433; P < 0.047). Hypocalcaemia and hypomagnesaemia with concurrent plumbism (more pronounced in CP) was observed in children with ASD and CP in this study).