Korean J Nephrol.
1997 Sep;16(3):488-494.
Investigations of Familial Tendency in Idiopathic Hypercalciuria of Childhood
- Affiliations
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- 1Department of Pediatrics, College of Medicine, Korea University, Seoul, Korea.
Abstract
- Idiopathic hypercalciuria is one of the major causes of asymptomatic hematuria in children and adults. However, the etiology of idiopathic hypercalciuria(IH) is not conclusive. In spite of many hypothesis about its genetic predisposition, the evidence for a genetic basis in the pathogenic mechanism of IH is fragmentary. In this study, we evaluated familial tendency and environmental factors influencing the pathogenesis of this disorder in patients with IH and their families. We investigated 24 children with IH and their 72 first-and second-degree relatives in this study. Twenty four patients had visited department of Pediatrics, Korea University Guro Hospital between July 1991 and July 1994 and had been diagnosed as IH. We measured fasting urine Ca/Cr ratio of 72 relatives of patients and if it is over 0.21, measured excreted calcium level of 24-h urine and serum Ca, P, Mg, BUN, Cr concentrations and PTH level. To analyse some environmental factors, we interviewed them(24 patients and their 72 relatives) about socioeconomic statuses, medications, history of conditions leading to secondary hypercalciuria, and preference for calcium-rich foods. 1) Out of 24 patients, 15 were absorptive hypercalciuria(AH) and 9 were renal hypercalciuri(RH). 2) The family investigations revealed IH in 9 out of 72 relatives of the 24 index patients and also showed a familial tendency in 12.5%. The familial tendency was 26.7% in families of children with AH(4 of 15 families) and 55.6% in families of children with RH(5 of 9 families)(p<0.05). 3) In personal interviews, there were no significant differences of nutritional habit between patients with AH and patients with RH. And then, the mean urine Ca/Cr ratio was significantly higher in the group preferring calcium-rich diet(18 persons) than in the group preferring calcium-low diet(14 persons) (p<0.05). We conclude that idiopathic hypercalciuria, especially, renal hypercalcuria, seems to have a familial tendency.
