RESUMO
Clinical and molecular data of 59 affected persons from 36 unrelated families with XLH (36 probands and 23 members of their families) were analysed. Characteristic phenotypic features (degree of leg deformities, growth failure, tooth abnormalities, tubular reabsorption of phosphate, serum phosphate and 1,25-dihydroxyvitamin D3 concentrations, head length and hearing defect in some cases) were assessed in relation to the type and localisation of 29 different PHEX gene mutations. The severity of clinical symptoms did not strictly depend upon the type and localisation of the PHEX gene mutation. A hearing defect was correlated with mutations in the beginning fragment, while tooth abnormalities and increased head length with the mutations in the beginning and the terminal fragment of the gene. Phosphate and vitamin D3 supplementation usually slowed progressive growth retardation and leg bowing. Our results point to the probability that alternative splicing occurs in the PHEX gene, producing several active forms of the PHEX protein. Some of them might be involved in bone turnover and dentin formation, others in renal phosphate uptake and vitamin D3 metabolism.
Assuntos
Constituição Corporal , Crescimento , Antropometria , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Polônia , Fatores de Tempo , População UrbanaRESUMO
Clinical course of the idiopathic juvenile osteoporosis (IJO) was monitored in the group of 45 patients of both sexes with diagnosed disease, verified during follow-up period. The aim of the study was to evaluate the relationship between clinical symptoms and the results of biochemical, anthropometric, and densitometric measurements. An analysis of the obtained data enabled to distinguish the acute and chronic IJO phases. Evolution of the acute phase into chronic one was manifested by the cessation of pain and pathological gait stereotype, normalization of muscular strength, anthropometric parameters and urinary Pyr and DPyr excretion, as well as improvement in bone density. Hypercalciuria and increased urinary excretion of Pyr and DPyr, observed in the acute phase of IJO, may indicate that bone resorption exceeded bone formation. Tendency to maintain of alkaline phosphatase activity within lower limits of the normal values with slight increase during an improvement of densitometric parameters suggested transient osteoblast dysfunction.