Familial renal tubular syndrome

Denfs disease is a familial renal tubular syndrome characterized by low molecular-weight proteinuria, hypercalciuria, nephrolithiasis and eventual renal failure. Mutations in the CLC-5 chloride channel are the basis for this disease. In humans, this channel is expressed mainly in the kidney, and mutations in the human CLCN5 promoter region might be the cause of Denf s disease (Devuyst et al. 1999, Hayama et al. 2000). 

Dent s disease a familial renal tubular syndrome, characterized by low molecular weight proteinuria, hypercalciuria, nephrolithiasis, and eventual renal failure dermatitis inflammation of the skin dermographism over-sensihve reaction of the skin in which pressure or friction gives rise to a wheat so that a word traced is visible... 

LRP2/ megalin Loss-of-function (familial, autosomal recessive) Donnai-Barrow syndrome (brain malformation, renal tubular deficiency, diaphragmatic hernia)... 

The combination of hypophosphatemia, vitamin D resistance, osteomalacia, and rickets is seen in a number of syndromes (W24). These include (a) familial hypophosphatemic vitamin D-resistant rickets, a sex-linked, dominant disorder (P3), (b) familial vitamin D dependency, an autosomal recessive disorder due to la-hydroxylase deficiency (F19), and (c) nonfamilial hypophosphatemic osteomalacia (D9), considered by some workers (P3) to be a separate disease entity because of its late onset, its severity, and its lack of response to therapy. In addition, there are many inherited and acquired disorders which are associated with impairment of renal tubular reabsorption of phosphate, and these may be accompanied by hypophosphatemia, rickets, and relative vitamin D resistance. Serum alkaline phosphatase values in these disorders correlate poorly with the severity of the disease (A14) and with the response to therapy (E4, MclO, P7, S50). 

The association of idiopathic hypercalciuria, decreased bone density and renal hypouricernia in all the affected subjects distinguishes them from the two patients reported in the literature (4,5), having hypouricernia due to an isolated renal tubular defect. The family studied by us presents, to our knowledge, a hitherto undescribed syndrome. The etiological connection between the three components of this syndrome - renal hypouricernia, idiopathic hypercalciuria and decreased bone density - is not understood their relationships to one mutation are unclear. 

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