Disease expression in the family units stratified based upon age categories of the members evaluated using ANOVA with Tukey HSD. The bars are group means and the vertical brackets enclose 1 SE. (A) mean bone defects (BD) in 5-less than (<)10 years (F=3.56, df1, P=0.0395); 10-less than (<)17 years (F=2.84, df1, P=0.0753); greater than (>)17 years (F=1.22, df1, P=0.312), (B) frequency of sites with bone defects greater than or equal to 4 mm in 5-less than (<)10 years (F=1.69, df1, P=0.1997); 10-less than (<)17 years (F=6.85, df1, P=0.0038); greater than (>)17 years (F=2.72, df1, P=0.084), and (C) frequency of sites with bone defects greater than or equal to 5 mm in 5-less than (<)10 years (F=1.83, df1, P=0.1759); 10-less than (<)17 years (F=4.13, df1, P=0.0270); greater than (>)17 years (F=3.84, df1, P=0.0360).