FATTY-ACID OXIDATION DISORDERS AS PRIMARY CAUSE OF SUDDEN AND UNEXPECTED DEATH IN INFANTS AND YOUNG-CHILDREN - AN INVESTIGATION PERFORMED ON CULTURED FIBROBLASTS FROM 79 CHILDREN WHO DIED AGED BETWEEN 0-4 YEARS

Background-Disorders of fatty acid metabolism are known to be responsi ble for cases of sudden and unexpected death in infancy. At least 14 d isorders are known at present. 120 cases of sudden infant death syndro me (SIDS) had been examined for a prevalent mutation (G985) causing me dium chain acyl CoA dehydrogenase deficiency, which is inherited in an autosomal recessive mode. No over-representation of either homozygous or heterozygous cases was found. Aims-To investigate a broader spectr um of fatty acid oxidation disorders in a wider range of sudden deaths in infants and young children. Methods-Seventy nine cases of unexpect ed death in infants and young children younger than 4 years old were e xamined for a minimum of nine fatty acid oxidation disorders, using th e global [9,10-H-3] myristic acid oxidation assay in cultured fibrobla sts from achilles tendon biopsies taken at postmortem examination. Res ults-Three cases with fatty acid oxidation disorders and two carriers of the G985 mutation were found, all catagorised as non-SIDS or border line SIDS. The global assay used has the advantage of simplicity. Conc lusions-These results indicate that disorders of fatty acid oxidation play a small but significant role in the cause of unexpected death in infants and young children, and that infants and children dying in thi s way should be regarded as high risk candidates for metabolic disease s.