leukotriene-c4 and Microcephaly

Leukotrienes (LTs) are a group of biologically highly active compounds which mainly include the cysteinyl leukotrienes LTC4, LTD4, LTE4 and LTB4. Biosynthesis is limited to a small number of different cells including brain tissue. Besides their well known function in the mediation of inflammation and host defence, cysteinyl LTs have neuromodulatory functions in the brain. Here we describe the recently discovered first two cases with a defect in the synthesis of LTs, LTC4 synthesis deficiency which is characterised by severe muscular hypotonia, psychomotor retardation, failure to thrive, microcephaly, and by the total absence of cysteinyl LTs in body fluids and deficient synthesis of the primary cysteinyl LT, LTC4, in blood cells. We describe the clinical and biochemical findings as well as the pathophysiological aspects of this condition and of further defects suggested in the synthetic pathway of LTs. Moreover, certain disease states which are known to be associated with secondary disturbances of LT degradation are also discussed.. Leukotriene C4 synthesis deficiency represents a member of a newly recognised group of neurometabolic disorders which are probably underdiagnosed. Analysis of leukotrienes is recommended in all patients with neurological symptoms who have no apparently obvious metabolic cause.

Topics: Brain; Brain Diseases, Metabolic, Inborn; Eicosanoids; Failure to Thrive; gamma-Glutamyltransferase; Glutathione; Humans; Leukotriene C4; Membrane Proteins; Microcephaly; Muscle Hypotonia; Psychomotor Disorders

Cysteinyl leukotrienes (LTC4, LTD4, LTE4) are potent lipid mediators derived from arachidonic acid in the 5-lipoxygenase pathway that exert profound biological effects. We investigated synthesis and metabolism of leukotrienes in an infant who presented with muscular hypotonia, psychomotor retardation, failure to thrive, and microcephaly. The course of the disease was rapidly progressive and the infant died aged 6 months.. Cysteinyl leukotrienes and LTB4 were analysed in cerebrospinal fluid, plasma, urine, and stimulated monocytes by EIA. We measured [3H]-LTC4 formation from [3H]-LTA4 in monocytes and platelets by radio-high-pressure liquid chromatography.. Concentrations of LTC4 and its metabolites were below the detection limit in the cerebrospinal fluid, plasma and urine. LTC4 could not be generated in stimulated monocytes, whereas LTB4 synthesis was increased. [3H]-LTC4 could not be made from [3H]-LTA4 in the patient's monocytes or platelets.. In this patient, inability to synthesise LTC4 suggests a deficiency of LTC4 synthase. This defect is a new inborn error of human eicosanoid metabolism and may be associated with the clinical disorder. Leukotriene analysis should be done in all patients with neurological symptoms who are candidates for metabolic diseases.

Topics: Abnormalities, Multiple; Case-Control Studies; Consanguinity; Failure to Thrive; Female; Glutathione Transferase; Humans; Infant, Newborn; Leukotriene C4; Metabolism, Inborn Errors; Microcephaly; Muscle Hypotonia; Psychomotor Disorders