Peroxisomal Disorders

Familial adrenal insufficiency, achalasia, alacrima, peripheral neuropathy, microcephaly, normal plasma very long chain fatty acids, and normal muscle mitochondrial respiratory chain enzymes

Adrenal insufficiency has been associated with adrenoleukodystrophy and adrenomyeloneuropathy. In these diseases, plasma very long chain fatty acids are elevated. Peripheral neuropathy is frequently seen in adults with adrenomyeloneuropathy. We encountered two first cousins with adrenal insufficiency, who also developed peripheral neuropathy, achalasia, alacrima, and microcephaly. However, plasma very long chain fatty acids, pipecolic acid, phytanic acid, and cranial computed tomographic scan were normal. Muscle mitochondrial respiratory chain enzymes were also normal. This syndrome of adrenal insufficiency, achalasia, alacrima, microcephaly, and peripheral neuropathy is different from either adrenomyeloneuropathy or adrenoleukodystrophy.

Punctate epiphyses: a radiological sign not a disease

Punctate epiphyses are caused by a diverse group of conditions. They may be an inherited part of certain bone dysplasias or an incidental finding occurring occasionally in various disorders. The pattern of the puncta together with other radiologic findings aid in making the correct diagnosis.

Intrauterine-onset myoclonic encephalopathy associated with cerebral cortical dysgenesis

The intrauterine onset of convulsive syndromes has been documented only rarely, and previous reports have lacked detailed neuropathologic description. This report details a case of severe, intractable myoclonic encephalopathy, which, on the basis of severely abnormal paroxysmal fetal movement patterns confirmed by antenatal ultrasound, appears to have been of antenatal onset. The infant suffered an early demise and at autopsy showed features of a severe brain dysgenesis with polymicrogyria and superadded encephaloclastic features. Despite an extensive evaluation, the etiology of this condition remains elusive in our case. This case demonstrates that closer analysis of the qualitative features of fetal movements by, for instance, real-time ultrasound could aid in the antenatal diagnosis of neurologic, particularly convulsive, syndromes.

Lactic acidosis and mitochondrial dysfunction in two children with peroxisomal disorders

Mitochondrial myopathies and defects in oxidative phosphorylation have been described in some patients with peroxisomal disorders. Although peroxisomes and mitochondria play a role in the beta-oxidation of fatty acids, the metabolic interactions between the two are not well defined. Defects in peroxisomal beta-oxidation are associated with extracellular accumulation of very long-chain fatty acids and may be accompanied by alterations in the intracellular pool of fatty acyl-CoAs, which are known to alter mitochondrial function. This study was initiated to examine alterations in the intracellular pool of acyl-CoAs and mitochondrial function in two children with generalized disorders of peroxisomal function and clinical lactic/pyruvic acidaemia. Fibroblasts were cultured from skin biopsies obtained from one child with neonatal adrenoleukodystrophy (NALD) and another with rhizomelic chondrodysplasia punctata (RCDP). Fibroblast lactate oxidation was significantly inhibited in NALD by 76% and RCDP by 92% compared to control values of 1.9 +/- 0.1 nmol/min per mg protein. Pyruvate dehydrogenase (PDH) (mean +/- SEM; activity nmol/min per mg protein) was: NALD 0.55 +/- 0.02 (p < 0.01), RCDP 0.44 +/- 0.02 (P < 0.01), and controls 0.83 +/- 0.02. The acid-insoluble (long-chain and very long-chain) acyl-CoA levels (mean +/- SEM; pmol/mg protein) were: NALD 129 +/- 69 (p < 0.01), RCDP 65 +/- 15 (p < 0.05), and control 45 +/- 7. These two patients with generalized peroxisomal disorders exhibited an increase in intracellular acyl-CoA species accompanied by decreased PDH activity and clinical lactic/pyruvic acidaemia.