Earlier diagnosis and strict diets improve the survival rate and clinical course of long-chain 3-hydroxyacyl-CoA dehydrogenase deficiency

Aim Long‐chain 3‐hydroxyacyl‐CoA dehydrogenase deficiency (LCHADD) is a severe metabolic disease that, without treatment, often leads to premature death or serious handicap. The aim of this study was to evaluate the clinical course of LCHADD with the homozygous 1528G>C (E510Q) mutation when patients underwent strict dietary treatment. Methods From 1997 to 2010, 16 patients with LCHADD were diagnosed in Finland. They were followed up, and data were prospectively collected as they emerged. Clinical data before diagnosis were retrospectively collected from hospital records. This cohort was compared with an earlier cohort of patients diagnosed from 1976 to 1996. Results The disease presented from birth to five months of age with failure to thrive, hypotonia, hepatomegaly, metabolic acidosis, cardiomyopathy and hypoketotic hypoglycaemia. In this cohort, the therapeutic delay was 0–30 days and the survival rate at the end of the study was 62.5% compared with 10‐year survival rate of 14.3% for the earlier cohort. The survivors were in good overall condition, but some of them had developed mild retinopathy or mild neuropathy. Conclusion Earlier diagnosis and stricter dietary regimes improved the survival rates and clinical course of patients with LCHADD in Finland. However, improvements in therapy are still needed to prevent the development of long‐term complications, such as retinopathy and neuropathy.