Los niños del Cauca II. Receptor de la vitamina D con secuencia normal en un foco de pacientes con raquitismo dependiente de la vitamina D, tipo II

Abstract

The vitamin D dependent rickets, type II (VDDR Il) is an autosomal-recessive disease, resulting from target-organ resistance to the action of the active hormonal form of vitamin D (1,25-dihydroxivitamin D,). This defect is due to an impairment in vitamin D receptor (VDR) function. The cloning and nucleo de sequence determination of the human VDR cDNA have enabled a direct evaluation of the genetic basis for the disease in affected patients. In this report, we employed PCRand cloning techniques to petform automated DNA sequencing on the VDR from two VDDR II patients who belong to a previously described cluster in Cauca (Colombia). Analysis of the VDR cDNA sequence from these patients failed to disclose any mutations. This finding suggests a new variant of resistance to 1,25-dihydroxi vitamin D, involving a VDR related posttranscriptional or posttranslational abnormality.