MILD OR ABSENT CLINICAL SIGNS IN TWIN SISTERS WITH SHORT-CHAIN ACYL-COA DEHYDROGENASE-DEFICIENCY

Two HLA-identical twin sisters are reported, of whom one has remained essentially asymptomatic, and an episode of hypotonia and decreased le vel of conciousness being the only relevant clinical finding in the ot her. Organic acid analysis revealed that ethylmalonate was constantly, although sometimes only slightly, increased. No abnormal acylglycines or acylcarnitines could be detected. Enzyme assay in cultured skin fi broblasts confirmed short-chain acyl-CoA dehydrogenase deficiency. Con clusion The lack of appropriate biochemical markers for this deficienc y makes the diagnosis difficult and consequently, the low number of pa tients described may be the result of underdiagnosis.