TY - JOUR
TI - Calcium and vitamin D metabolism in hypocalcemic vitamin D-resistant
rickets carriers
AU - Nicolaidou, P
AU - Papadopoulou, A
AU - Georgouli, H
AU - Matsinos, YG and
AU - Tsapra, H
AU - Fretzayas, A
AU - Giannoulia-Karantana, A
AU - Kitsiou, S
AU - and Douros, K
AU - Papassotiriou, I
AU - Chrousos, GP
JO - Frontiers of Hormone Research
PY - 2006
VL - 65
TODO - 2
SP - 83-88
PB - Karger
SN - null
TODO - 10.1159/000091043
TODO - hypocalcemic vitamin D-resistant rickets carriers; calcium and vitamin D
metabolism; vitamin D receptor; 1,25(OH)(2)D-3; parathyroid hormone
TODO - Background/Aims: Hypocalcemic vitamin D-resistant rickets (HVDRR) is a
rare monogenic autosomal recessive disorder associated with mutations in
the gene of the vitamin D receptor (VDR), the mediator of 1,25(OH)(2)D-3
action. Although many investigations have discussed the clinical
manifestations and molecular etiology of this disease, only a few have
investigated the biochemical and hormonal status of heterozygous HVDRR.
The aim of the current work was to investigate the profile of selected
biochemical and hormonal parameters related to the vitamin D endocrine
system in a large number of HVDRR heterozygotes. Methods: 67 relatives
of 2 HVDRR patients, all members of an extended Greek kindred of five
generations with a common ancestor, were included in the study. Direct
sequencing was used to identify VDR gene mutations. Serum Ca, P,
25(OH)D, iPTH, and 1,25(OH)(2)D levels were determined in all members of
the kindred. Results: DNA analysis of the participants led to the design
of two study groups: the HVDRR carriers (24) and the control subjects
(43). Our results showed elevated circulating serum levels of
1,25(OH)(2)D-3 and lower levels of PTH than their age- and sex-matched
controls. No hypocalcemia or hypophosphatemia were detected in HVDRR
carriers. Conclusions: Our findings suggest that HVDRR carriers may have
compensatory elevated serum levels of 1,25(OH)(2)D-3 through which they
restrain PTH secretion. The study of HVDRR carriers could be a useful
tool for the investigation of the vitamin D endocrine system. Copyright
(c) 2006 S. Karger AG, Basel.
ER -