Lychee-Associated Hypoglycaemic Encephalopathy: A New Disease of Children Described in India

Fruits of lychee tree (Litchi sinensis), extensively horticultured in India, China and many other countries, are delicious and possess many nutritious and medicinal properties. In India and other Asian countries, in lychee harvest season, outbreaks have been occurring of rapidly developing hypoglycaemia, encephalopathy, seizures and cerebral oedema in young children when they ingest lychee fruit arils in large numbers on empty stomach. It has been shown that the acute neurological illness is hypoglycaemic encephalopathy, caused by the actions of hypoglycin A (HGA) and methylenecyclopropylglycine (MCPG), the non-protein l-amino acids present in the edible arils of lychee fruits. Both HGA and MCPG phytotoxins are known to disrupt the pathways of β-fatty acid oxidation and gluconeogenesis in human body cells, result in accumulation of many undesirable metabolites of the blocked energy generating pathways, and altogether produced the often fatal hypoglycaemic illness. Here, the related work is summarized and commented upon and prospective genetical interventions in Litchi sinensis to eradicate the problem are outlined. Toxin-deficient lychee genotypes need to be developed by screening of germplasm accessions, and use of conventional and new site-directed mutagenesis technique of plant breeding. Lychee trees that produce super-toxin-rich (× 10 average toxin concentration) fruits are required to be identified and tagged to stop consumption of their fruits. New plantings must use toxin-deficient (low-toxin) lychee genotypes.