Late form of VKDB is a rare but serious disease which can be prevented by VK-prophylaxis.

We report the identification of two new 7-year-old patients with 3-hydroxy-2-methylbutyryl-CoA dehydrogenase deficiency, a recently described inborn error of isoleucine metabolism. The defect is localized one step above 3-ketothiolase, resulting in a urinary metabolite pattern similar to that seen for deficiency of the latter. One patient has progressive neurodegenerative symptoms, whereas the clinical phenotype of the other patient is characterized by psychomotor retardation without loss of developmental milestones. A short-term biochemical response to an isoleucine-restricted diet was observed in both children.

Isolated MCC deficiency of early-onset is a rare condition exhibiting a more severe clinical course than the later-onset form described in most other cases. The prognostic value of 3 HIVA measurements in CSF and serum should be evaluated in future cases.

A new case of propionic acidemia is presented, paying special attention to the early symptoms of this disease, such as increased drowsiness, muscular hypotonia, poor feeding, hypothermia, metabolic acidosis, ketonuria and vomiting. Investigation by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) revealed the excretion of fairly high amounts of 2-methyl-3-oxovaleric acid, a condensation product of two molecules of propionyl-CoA, as well as the known pathological metabolites such as propionic, 3-hydroxypropionic and methylcitric acids. Among the post mortem findings the histological studies of the liver were the most remarkable.

During selective screening for organic acidurias, a 10-week-old girl with muscular hypotonia and recurrent fits was shown to be excreting 3-methylcrotonylglycin and 3-hydroxyisovaleric acid. Besides these metabolites of leucine the presence of small but pathological amounts of propionic and methylcitric acids were demonstrable in her urine, pointing to a defect in the metabolism of biotin. On treatment with biotin (2 x 5 mg/day) the convulsions stopped at once, her clinical condition improved gradually, and the abnormal metabolites disappeared from the urine. Within 6 weeks the child was discharged in a good general condition without apparent signs of neurological damage.