Background: Focal segmental glomerulosclerosis (FSGS) is the underlying pathologic entity in 5% of adults and 20% of children with end-stage renal disease (ESRD). FSGS is generally considered to be sporadic in origin.
Methods: Recently, we identified 60 families involving 190 individuals with familial FSGS, providing evidence for a subset of families in which a genetic form is segregating. Each family had at least one member with renal biopsy-confirmed FSGS and at least one other member with either renal biopsy-confirmed FSGS or ESRD.
Results: Twenty-six families had individuals affected in more than one generation [multigeneration (MG)], and the remaining 34 families had only a single generation (SG) affected. There was equal representation of males and females among affected individuals. Ten percent of MG families were African American, and 52% of SG families were African American. The mean age of presentation was significantly higher in the MG families (32.5 +/- 14.6 years) compared with the SG families (20.1 +/- 12.1 years, P = 0.0001). SG cases had higher levels of proteinuria at presentation (7.0 +/- 5.6 g/24 hr, compared with 3.8 +/- 3.4 g/24 hr, for the MG families, P = 0.002). On renal biopsy, tubulointerstitial damage was more severe in patients in the SG families than in the MG families; however, the level of glomerular damage did not differ between these groups. Fifty percent of the patients had progressed to ESRD by the age of 30 years. Variables measured at presentation that were independently associated with poor renal survival were decreased age, increased serum creatinine, and increased urinary protein excretion. Forty-one patients underwent successful renal transplantation, with a 10-year graft survival rate of 62%. One patient developed clinical and biopsy evidence of recurrence of FSGS in the allograft.
Conclusion: These data confirm the existence of a non-Alport's form of hereditary glomerulonephritis, which has a morphological pattern of FSGS.