RESUMEN
OBJECTIVE: Description of rickets as an unexpected initial manifestation in two children with abetalipoproteinemia and hypobetalipoproteinemia, and elucidation of its pathophysiology in these conditions. METHODOLOGY: Two infants aged two and six months with abetalipoproteinemia and hypobetalipoproteinemia respectively had clinical rickets at presentation, confirmed radiologically and biochemically. Vitamin D intake and serum levels were measured and other causes of rickets were looked for. RESULTS: Vitamin D intake and laboratory studies levels were suggestive of rickets due to calcium deficiency instead of vitamin D deficiency. Healing of rickets occurred with dietary treatment of the malabsorption, without any dietary calcium or significant vitamin D supplementation. CONCLUSION: Steatorrhea-induced calcium malabsorption seems to be the most likely cause of rickets in this entity.
Asunto(s)
Abetalipoproteinemia/complicaciones , Hipobetalipoproteinemias/complicaciones , Raquitismo/complicaciones , Abetalipoproteinemia/metabolismo , Calcio/metabolismo , Femenino , Humanos , Hipobetalipoproteinemias/metabolismo , Lactante , Síndromes de Malabsorción/complicaciones , Síndromes de Malabsorción/metabolismo , Masculino , Raquitismo/etiología , Raquitismo/metabolismoRESUMEN
Familial persistent hyperinsulinemic hypoglycemia of infancy (PHHI), an autosomal recessive disorder characterized by unregulated insulin secretion, is linked to chromosome 11p14-15.1. The newly cloned high-affinity sulfonylurea receptor (SUR) gene, a regulator of insulin secretion, was mapped to 11p15.1 by means of fluorescence in situ hybridization. Two separate SUR gene splice site mutations, which segregated with disease phenotype, were identified in affected individuals from nine different families. Both mutations resulted in aberrant processing of the RNA sequence and disruption of the putative second nucleotide binding domain of the SUR protein. Abnormal insulin secretion in PHHI appears to be caused by mutations in the SUR gene.
Asunto(s)
Transportadoras de Casetes de Unión a ATP , Hiperinsulinismo/genética , Hipoglucemia/genética , Enfermedades Pancreáticas/genética , Canales de Potasio de Rectificación Interna , Canales de Potasio/genética , Receptores de Droga/genética , Secuencia de Aminoácidos , Secuencia de Bases , Mapeo Cromosómico , Cromosomas Humanos Par 11 , Análisis Mutacional de ADN , ADN Complementario/genética , Genotipo , Humanos , Lactante , Insulina/metabolismo , Secreción de Insulina , Datos de Secuencia Molecular , Mutación , Fenotipo , Mutación Puntual , Canales de Potasio/química , Empalme del ARN , Receptores de Droga/química , Compuestos de Sulfonilurea/metabolismo , Receptores de SulfonilureasRESUMEN
A problem-orientated case record was used for the investigation and management of neonatal jaundice. Investigation of babies requiring phototherapy rarely showed any abnormality but we consider that such routine investigations are worth retaining. There were problems in the interpretation of moderately low plasma concentrations of thyroxine in small, preterm babies. There was biochemical evidence of hepatitis in 3 babies; in all 3 the biochemical abnormality was mild and had disappeared 6 months later in 2 of them. It may be that mild episodes of the neonatal hepatitis syndrome are more common than have been thought and that such infants have a fairly good prognosis.