[Oxidative phosphorylation defects with neonatal presentation: review of our caseload].

OBJECTIVES: To define the oxidative phosporilation deficit syndrome in the neonatal in terms of incidence and clinical, biochemical and genetic features. MATERIAL AND METHODS: We report 9 newborns diagnosed as oxidatic phosporilation deficit during the last 8 years in our hospital by means of clinical, metabolic, pathological and molecular studies, among other evaluations. The diagnosis was established based on ensymatic deficit of the respiratory chain, associated with alterations in the mtDNA in one case, and with mitochondrial ultrastructural anomalies in 5 cases. RESULTS: There was an incidence of 1/3.555 newborns and 1/832 newborns admitted in our Neonatal Unit. In four of them there were familial antecedents and polihidramnios in two. Most of them, 8 out of 9, were born at term after a normal pregnancy and delivery, with normal Apgar score and auxological examination. Symptomatology started immediately at the neonatal period as acute neurological damage in most of them. There was a severe evolution as 5 children died and 4 survived with severe damage. All of them had the classical phenotype of early severe encefalopathy, associated with dismorphic features, hypotomia, neurosensorial defects, brain dysgenesis and atrophy, anomalies in the EEG and in 5 of them there were also systemic anomalies, mainly cardiopathy. The most frequent biochemical alteration was a significative increment of the quotient lactate/piruvate. Five patients presented ultrastructural alterations of the mitochondria in thr muscle biopsy but Cox stain was not positive in any case. Three cases has a deficit of the complex IV, e of the complex I-IV, 2 of the complex I and one the complex I-III-IV. Only one patient had multiple deletions in the mtDNA. CONCLUSIONS: Oxidatic phosporilation deficit are frequent and severe diseases of prenatal onset with limited fetal effects, homogeneous clinical phenotype with frequent damage of the central nervous system and variable extraneurological alteration and inconsistent biochemical pattern. Enzymatic studies ar need for making the diagnosis in all suspected cases,