Page 118 - Characterization of genetic neurodevelopmental disorders at adult age, with a focus on 22q11.2 deletion syndrome - Emma Boersma

Chapter 3
Sample
In total, 856 individuals (454 females, 53.0%) aged 16 years and older
with a molecularly confirmed typical 22q11.2 deletion (i.e., including the
LCR22A-LCR22B region)7 entered the study. The median age of the study
sample was 29 (range 16 – 76) years. Additional information regarding
demographic and patient characteristics of the study sample is presented
in Supplementary Table 1.
Identification and characterization of adults with Parkinson’s disease
We systematically extracted data on demographic variables (sex and age
at last clinical assessment, death, or at the time of chart review (Toronto)),
results of genetic analysis, history of medication use, medical history, and
available information on PD expression (including dopaminergic imaging)
and treatment. We defined PD as a clinical diagnosis by a neurologist,
including bradykinesia and at least one of either rest tremor or rigidity,8 and
suspected PD as a clinical diagnosis or suspicion of PD but failure to meet
all above criteria for PD. This separate category of adults with suspected
PD was included to account for the fact that there were several adults with
a clinical suspicion of PD, who did not meet all criteria for PD. Reasons for
not meeting the formal criteria included lack of information in the medical
file regarding parkinsonian motor features in the presence of a clinical PD
diagnosis (n=3), or a clinical suspicion of PD based on supportive criteria,
such as positive treatment response, without a formal PD diagnosis (n=11).
Seven cases with PD and no cases with suspected PD were reported
previously.2, 4
Data presentation and analysis
We calculated prevalence rates of PD and their 95% confidence intervals
(95% CIs), using the formula CI= p ± 1.96* √(p(1-p)/n), per sex and age
group.8 Pearson’s chi-square tests were used to compare PD prevalence
rates between groups (i.e., sex and age). The observed number of PD cases
in adults with 22q11.2DS was compared with the expected number of PD
cases based on data from the general population within the age group of
40-69 years, using an age adjusted standardized morbidity ratio (SMR).8
This age group was based on the availability of population based data from
the age of 40 years,8 and the limited number of adults with 22q11.2DS
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