Respiratory Chain Defects May Present Only with Hypoglycemia

International audienceHypoglycemia occasionally results from oxidative phosphorylation deficiency, associated with liver failure. Conversely, in some cases of respiratory chain defect, the impairment in glucose metabolism occurs with normal hepatic function. The mechanism for this hypoglycemia remains poorly understood. We report here three unrelated children with hypoglycemia as the presenting symptom associated with oxidative phosphorylation deficiency but without liver dysfunction. Two patients had, respectively, complex III and complex IV deficiency and presented with long fast hypoglycemia. During a fasting test, the first patient showed evidence for impaired gluconeogenesis (progressive increase of plasma lactate and no decrease of alanine levels), whereas the second patient appeared to have impaired fatty acid oxidation (hypoketotic hypoglycemia with increased levels of non esterified fatty acids). The third patient presented with both long and short fast hypoglycemia related to complex IV deficiency. The mechanism of hypoglycemia for this patient may have been partly related to GH insufficiency, whereas impaired glycogen metabolism possibly accounted for short fast hypoglycemia. We suggest that hypoglycemia can be the presenting symptom for respiratory chain defects, through the possible reduction in cofactors resulting from oxidative phosphorylation deficiency, and that respiratory chain defects should therefore be considered in the differential diagnosis of hypoglycemia

Massive subdural haematomas in Menkes disease mimicking shaken baby syndrome.

INTRODUCTION: Menkes disease is an X-linked inherited disorder of intestinal copper absorption resulting in copper deficiency. Cardinal features include hair abnormalities, facial dysmorphism, severe neurological impairment, hypothermia, arterial anomalies, bone abnormalities and a fatal outcome. CASE REPORT: We present a case of Menkes disease complicated by progressive macrocephaly following the development of massive subdural haematomas. These lesions associated with femoral metaphyseal spurs could be confused with nonaccidental injury such as that seen in the shaken baby syndrome. DISCUSSION: This case emphasises that Menkes disease, like glutaric aciduria type 1, should be included in the differential diagnosis of unexplained subdural haematomas and neurological deficits in infants