VITAMIN-D-DEPENDENT RICKETS TYPE-II AND NORMAL VITAMIN-D-RECEPTOR CDNA SEQUENCE - A CLUSTER IN A RURAL AREA OF CAUCA, COLOMBIA, WITH MORE THAN 200 AFFECTED CHILDREN

Vitamin D dependent rickets type II is an autosomal recessive disease caused by the vitamin D defective receptor. More than 200 patients wit h different types of lower limb deformities were detected in a rural a rea of the Cauca department in the southwest part of Colombia. Patient s were well nourished and in good physical condition in spite of their deformities. None of them presented alopecia, myopathy, seizures or a minoaciduria. Serum analysis showed significantly lower serum calcium as compared to normal relatives, though in the normal low range, norma l phosphorus, high alkaline phosphatase, normal 25-hydroxyvitamin D-3 and high 1,25-dihydroxyvitamin D-3, indicating target organ resistance . The cDNA analysis showed normal nucleotide sequence. We suggest that our patients represent a distinct form of receptor-positive resistanc e to vitamin D. This report is the first extensive study on this class of patients.