RESUMEN
A 38-day-old male infant with persistent pulmonary hypertension and respiratory failure since birth was found to have a complete absence of surfactant protein B (SP-B) along with an aberrant form of SP-C in his tracheal aspirate fluid, findings consistent with the diagnosis of hereditary SP-B deficiency. Surprisingly, SP-B and SP-B messenger ribonucleic acid were present in lung biopsy tissue. However, DNA sequence analysis demonstrated a point mutation in exon 5 of one of the SP-B gene alleles. The infant's mother was found to be a carrier of this mutation. The infant's other SP-B allele did not differ from the published DNA sequence for the SP-B gene. We conclude that this patient had a transient deficiency of SP-B, in contrast to that of previously described infants with irreversible respiratory failure caused by hereditary SP-B deficiency. We recommend that infants with suspected SP-B deficiency have serial analysis of tracheal fluid samples for both SP-B and SP-C before lung biopsy, along with genetic analysis for the known SP-B mutations. We speculate that the new mutation found in one of this patient's SP-B genes was in part responsible for the transient deficiency of SP-B.
Asunto(s)
Errores Innatos del Metabolismo/genética , Proteolípidos/metabolismo , Surfactantes Pulmonares/deficiencia , Surfactantes Pulmonares/metabolismo , Síndrome de Dificultad Respiratoria del Recién Nacido/metabolismo , Exudados y Transudados/química , Humanos , Immunoblotting , Lactante , Recién Nacido , Masculino , Errores Innatos del Metabolismo/complicaciones , Mutación , Reacción en Cadena de la Polimerasa , Proteolípidos/genética , Surfactantes Pulmonares/genética , Síndrome de Dificultad Respiratoria del Recién Nacido/complicaciones , Análisis de Secuencia de ADN , Factores de Tiempo , TráqueaRESUMEN
A comatose male newborn infant with congenital lactic acidosis caused by pyruvate decarboxylase deficiency was treated with dichloroacetate (DCA), which stimulated an 88% drop in serum lactate concentration and reversed his coma. The response to DCA was temporary and the lactic acidosis worsened until his death, but DCA may confer more lasting benefit in less severely affected infants.