Racial variation in autosomal dominant polycystic kidney disease

These analyses were undertaken to determine whether racial variation contri butes to the risk of end-stage renal disease (ESRD) in close relatives of i ncident dialysis patients with autosomal dominant polycystic kidney disease (ADPKD)-associated ESRD, A family history of ESRD was recorded in 14,769 i ncident ESRD patients in Network 6 (Georgia, North Carolina, South Carolina ) between September 1993 and November 1997, Two hundred thirty-seven patien ts with ADPKD-ESRD comprised the study population (180 white and 57 black), Differences in patient populations were analyzed using the chi-squared and Student's t-tests, and multiple regression analysis was performed. Correla tion in age at ESRD onset in families was performed by linear regression an alysis. A positive family history (FH) of ESRD in first- or second-degree r elatives was reported by 38.6% (22 of 57) of blacks and 55% (99 of 180) of whites (P = 0.03), The 22 blacks with a positive FH had a mean of 2.0 addit ional ESRD relatives and 10.4 total first-degree relatives, whereas the 99 whites with a positive FH had a mean of 2.6 additional ESRD relatives and 7 .0 total first-degree relatives (P = 0.14 and P < 0.001, respectively). Mea n age in years at first dialysis was similar in blacks and whites, regardle ss of FH (black FH positive, 63.8; black FH negative, 66.3; P = 0.66; white FH positive, 60.8; white FH negative, 62.8; P = 0.48), On average, 57.9% o f the first- and second-degree relatives of white cases had ADPKD-associate d ESRD, compared with 28.6% of the relatives of black cases (P < 0.001), In the multivariate analysis, white race (P = 0.004) and increasing family si ze (P = 0.002) were positively correlated with the number of relatives havi ng ADPKD-associated ESRD, whereas age at ESRD onset (P = 0.50) and gender ( P = 0.94) were not. Age at onset of ESRD was correlated within members of m ultiply affected white (P < 0.001) but not black families (P = 0.80), We co nclude that blacks with ADPKD-associated ESRD are less likely than whites t o have relatives with ESRD, and there is no correlation in age at onset of ADPKD-ESRD in black families. (C) 2000 by the National Kidney Foundation, I nc.