Results
Sixteen subjects/parents or guardians completed the medical history
questionnaire (MHQ) and medical record requests (See Table 1). The
average age of the study subject at the time of completion was 22 years
(range 7 to 48 years). Sixteen subjects had at least one functional
disability scale score available. The average age at which the first
functional disability scale (FDS1) score was obtained was 19 years
(range 7 to 42 years; standard deviation 10.7 years). Nine of those
individuals had at least two functional disability scale scores
available. The average age at which the second functional disability
scale (FDS2) score was obtained was 29 years (range from 14 to 48
years). The average number of years of follow-up from FDS1 to FDS2 was
5.4 years (range 4 to 7 years). Two individuals had a third functional
disability scale score available. The average age at which the third
functional disability scale (FDS3) score was obtained was 48.5 years
(range 46 to 51 years). The average number of years of follow-up from
FDS2 to FDS3 was 5.5 years. In total, three sibling pairs were included
in this study.