Figure 3.

After dividing the 335 individuals from 300 families with steroid-resistant nephrotic syndrome by gene identification status (steroid-resistant nephrotic syndrome gene, phenocopy gene, no mutation detected) and sorting by age and sex, the median age of individuals with a mutation detected in a steroid resistant nephrotic syndrome gene is significantly lower than the median age of individuals with a mutation detected in a phenocopy gene or individuals with no mutation detected. (A) Families in whom a causative mutation in a known steroid-resistant nephrotic syndrome gene (blue) or phenocopy gene (orange) was detected as compared with those families where no causative mutation was detected (gray). Bars and numbers at end of bars represent number of affected individuals in each category, divided into those with a causative mutation detected in a steroid-resistant nephrotic syndrome gene (blue), those with a causative mutation detected in a phenocopy gene (orange), and those without a causative mutation detected (gray). Percentages at end of each bar reflect the same three categories. Percentages>10% are rounded to the nearest whole number. (B) Median age of onset in patients with a causative mutation detected in a steroid-resistant nephrotic syndrome gene was 1.7 years versus 4 years in those without a mutation detected (range, 0–24 years). For those with a causative mutation detected in a steroid-resistant nephrotic syndrome gene, the range was 0–21 years. Mann–Whitney U test P<0.01. Median age of individuals with a phenocopy mutation detected was 4 years (range, 0.3–16), which was not statistically significant. Data of the characteristics of the steroid-resistant nephrotic syndrome cohort compared with the subcohort of those individuals with a causative mutation detected in a steroid-resistant nephrotic syndrome gene or phenocopy gene are given in Supplemental Table 3. SRNS, steroid-resistant nephrotic syndrome.