Sialic acid and anti-ganglioside antibody levels in children with autism spectrum disorders.

BACKGROUND: Autism spectrum disorders (ASD) may result from a combination of genetic and environmental factors, and impact neurological functions and behaviors. Sialic acid (SA) is an indispensable nutrient for early brain development, and its polymer polySia (PSA) can modify neural cell adhesion molecules (NCAM), thereby indirectly mediating neuronal outgrowth, synaptic connectivity and memory formation. To investigate the association between SA and ASD, we conducted a case-control study. METHODS: The study sample included 82 autistic children and 60 healthy children. We measured the levels of plasma SA and serum anti-gangliosides M1 antibodies (anti-GM1 antibodies) in the ASD and control groups. We also examined the severity of autistic children. RESULTS: The level of plasma SA in the control group was significantly higher than that in the ASD group (p < .01). Autistic children had higher positive rates of anti-GM1 antibodies (37.8%) than controls (21.67%, P = .04). However, there was no correlation between autistic severity and the levels of SA. SA may be as a biomarker for diagnosis of ASD with a positive predictive value of 84.42%, a negative predictive value of 73.85% and an area under the ROC curve value of 0.858. CONCLUSIONS: These results indicate that SA and anti-GM1 antibodies are associated with ASD. Our data suggested that future studies to explore the function of SA in the etiology of ASD may be needed.

Adult-onset Krabbe disease presenting with an isolated form of peripheral neuropathy.

INTRODUCTION: Adult-onset Krabbe disease is clinically rare and usually affects the pyramidal tracts in the central nervous system. Patients develop a spastic gait, and peripheral neuropathy sometimes occurs simultaneously. METHODS: A 55-year-old woman with consanguineous parents developed slowly progressive, asymmetric muscle weakness and atrophy in her forearms, while her ability to walk remained unaffected without pyramidal tract signs after onset at age 51 years. RESULTS: Nerve conduction studies demonstrated an asymmetric demyelinating-type peripheral neuropathy, and sural nerve biopsy documented reduced myelinated nerve fiber density with uniformly thin myelin sheaths, suggesting hypomyelination. Brain MRI demonstrated minor white-matter injury along the optic radiations, which was associated with asymptomatic, mild, prolonged latency on visual evoked potentials. Laboratory analysis documented low enzyme activity of galactocerebrosidase (GALC) and a known mutation of the GALC gene. CONCLUSION: Isolated peripheral neuropathy occurs very rarely in adult-onset Krabbe disease. Muscle Nerve 54: 152-157, 2016.