A genetic disorder characterized by deficiency of the enzyme long-chain acyl-coenzyme A dehydrogenase that metabolizes long-chain fatty acids. Signs and symptoms appear in infancy or childhood and may be triggered during fasting, illness or exercise. They include hypoglycemia, muscle weakness and lethargy. The disease is MONDO_0020531 (long chain acyl-CoA dehydrogenase deficiency). Also known as: LCAD, acyl-CoA dehydrogenase, long-chain deficiency, inborn error of long-chain-acyl-CoA dehydrogenase activity, inborn long-chain-acyl-CoA dehydrogenase activity disorder, long-chain acyl-CoA dehydrogenase deficiency, long-chain acyl-Coenzyme A dehydrogenase deficiency, rare inborn error of long-chain-acyl-CoA dehydrogenase activity.