Red blood cell ghosts are affected by adrenoleucodystrophy

Blood lipids in Antarctic and in temperate-water fish species

Antarctic fish live in very cold water and have adapted to this exceptional environment. Hemoglobin is absent or very low; yet these fish still have erythrocytes, and from these we prepared ghost-like membranes. We studied for the first time the lipid composition of ghost membranes and of plasma in Antarctic fish (C. hamatus and T. bernacchii) and compared our results with those obtained for temperate-water fish (C. auratus and A. anguilla taken from Lake Trasimeno, Perugia, Italy). The membranes of Antarctic fish were richer in glycerophospholipid (especially phosphatidylethanolamine), whereas the membranes of temperate-water fish were richer in sphingomyelin. Unsaturated fatty acids were particularly abundant in Antarctic fish: C. hamatus had long-chain unsaturated fatty acid (especially C22:6 omega-3), whereas T. bernacchii had shorter unsaturated fatty acyl chains (c16:1, omega-7). On the other hand, C. auratus and A. anguilla were particularly rich in C16:0, which constituted more than one-half of the total fatty acid. Plasma lipids (both phospholipid and cholesterol) were much more abundant in temperate-water fish. The differences in phospholipid content were mainly due to choline glycerolipids. Measures of membrane fluidity inferred from the fluorescence anisotropy of DPH indicated that the membranes from Antarctic fish were more fluid at any measured temperature than those obtained from fish living in temperate waters. The ability to live in a very cold environment has therefore been achieved by the two Antarctic species tested in this paper by different strategies, but with the same results on fluidity.

Newborn screening for adrenoleukodystrophy: implications for therapy

X-Linked adrenoleukodystrophy (X-ALD) is a progressive metabolic condition affecting the adrenal glands and nervous system of males. Although variable in the age of onset and presentation in families, X-ALD does present in characteristic phenotypes including a devastating childhood form that affects 35% of boys with this genetic condition. The majority of males with X-ALD will also develop adrenal insufficiency, which may result in crisis. Early detection is desirable in order to prevent morbidity from this condition. We have recently developed a tandem mass spectroscopy method that allows this to be done during newborn screening for other genetic disorder. In this review, we discuss the rationale for early detection, its effect on treatment, and some of the uncertainties.