Περίληψη:
Background/Aims: Hypocalcemic vitamin D-resistant rickets (HVDRR) is a
rare autosomal recessive disorder characterized by severe rickets,
hypocalcemia, secondary hyperparathyroidism, elevated levels of
1,25-dihydroxyvitamin D-3 [ 1,25( OH) 2 D 3], and occasionally,
alopecia. In most cases, the disease is associated with mutations in the
gene of the vitamin D receptor (VDR), the mediator of 1,25(OH)(2)D-3
action. The apparently healthy HVDRR heterozygotes express both normal
and mutant VDR alleles, and they present higher levels of 1,25(OH)(2)D-3
than their respective controls. Because VDR function, except for the
disease-causative mutations, might be influenced by the presence of
certain polymorphisms, we investigated the distribution of four common
VDR polymorphisms - BsmI, ApaI, TaqI and FokI - in HVDRR carriers
compared with their respective controls. Methods: Sixty-seven relatives
of 2 HVDRR patients, all members of an extended Greek kindred, were
included in the study. VDR allelic polymorphisms were assessed by
restriction fragment length polymorphisms after specific polymerase
chain reaction amplification. Results: The distribution of genotypic and
allelic frequencies differed between HVDRR carriers and their respective
controls regarding BsmI and TaqI polymorphisms. The bb genotype and the
T allele (presence of BsmI and absence of TaqI polymorphisms) were less
frequent in the HVDRR carrier group than in the control group in a
statistically significant manner (p = 0.029 and p = 0.025,
respectively). Conclusions: Our findings showed that the apparently
healthy HVDRR carriers present a different distribution of BsmI and TaqI
VDR polymorphisms than their controls, suggesting that further
investigation of the HVDRR carrier population may elucidate the
implication of VDR alleles in VDR function and the vitamin D endocrine
system. Copyright (c) 2007 S. Karger AG, Basel.
Συγγραφείς:
Nicolaidou, Polyxeni
Papadopoulou, Anna
Matsinos, Y. G. and
Georgouli, Helen
Fretzayas, Andreas
Papadimitriou, Anastasios
and Priftis, Kostantinos
Douros, Konstantinos
Chrousos, George
P.
