PWS impacts many aspects of our children’s lives. The hallmark struggle for those affected by PWS is hyperphagia, or excessive appetite. But beyond hyperphagia, individuals with PWS are susceptible to other behavioral and emotional problems that affect both their quality of life and that of their families. As a patient advocacy organization for parents and families of people with PWS, FPWR is focused on accelerating the search for effective treatments to help our loved ones.
When developing new medicines and other treatments to treat symptoms that people with PWS experience, researchers need a reliable way to show potential improvements in those symptoms. For some symptoms, measuring this is clear-cut, such as changes in weight or hormone levels in the blood. But in PWS, often the symptoms that are being addressed are behavioral or emotional features, which are harder to measure. In addition, these symptoms in PWS are, in some ways, quite unique and specific to the syndrome. What is needed is an assessment tool that is specific to PWS and the particular issues that our loved ones struggle with.
One such measure is the Hyperphagia Questionnaire for Clinical Trials (HQ-CT), which measures hyperphagic behaviors commonly seen in PWS. The HQ-CT, based on the original hyperphagia questionnaire developed by Elisabeth Dykens, Elizabeth Roof, and colleagues at Vanderbilt University, has been used in several clinical trials to help assess the effectiveness of treatments for hyperphagia. But, until now, we have lacked a tool to adequately measure the unique behavioral profile seen in PWS.
Without this type of instrument, we can’t test whether a new medicine or behavioral intervention helps treat the other challenges in PWS beyond hyperphagia, such as rigid thinking, anxiety and depressive symptoms, repetitive questions, temper outbursts, or skin picking. Thanks again to the research team at Vanderbilt University, Elisabeth Dykens, Elizabeth Roof, and Haille Hunt-Hawkins, a new tool has been developed to measure these challenging PWS-specific behaviors. In this 4-phase study, the research team at Vanderbilt leveraged their extensive experience in PWS behaviors, along with feedback from families and specialists, to develop and validate the PWS Profile.1 They saw the critical need for a PWS-specific tool to evaluate treatment efficacy in clinical trials and other treatment studies aimed at reducing behavioral and emotional problems in PWS.
"We are honored to provide a comprehensive, fully validated outcome measure of the core phenotypic features of PWS to be used in clinical trials that is shown to be sensitive to treatment effects.” - Elizabeth Roof, study investigator
The PWS Profile questionnaire was developed over a several-year process working with families as well as experts in the field, including members of the FPWR Clinical Trials Consortium. The final, 57-item profile was administered to 761 participants who were parents of individuals with PWS who were aged 5 and above. The parent participants were recruited from the Vanderbilt University PWS research program and from the Global PWS Registry.
The data from the PWS Profile was analyzed using factor analyses, which is a common approach used when developing a comprehensive questionnaire. Factor analysis is a statistical method used to reduce a large number of variables (or items on a questionnaire) into a smaller set of factors or concepts that fit together to help explain and interpret the data. In this study, the factor analysis of the PWS Profile data revealed eight conceptually meaningful factors, which were interpreted as: Rigidity/Insistence; Aggressive Behaviors; Repetitive Questioning/Speech; Compulsive Behaviors; Depression/Anxiety; Hoarding; Negative Distorted Thinking; and Magical Distorted Thinking. There was also an additional factor with only 2 items that reflected skin picking.
Psychometric data analysis showed that the PWS Profile demonstrated good reliability and validity. Other analyses revealed that the 8 PWS Profile factors were not related to IQ, body mass index (a measure of obesity), or parental socio-economic status. Some genetic subtype differences were found, with higher scores for individuals with PWS who had PWS due to uniparental disomy (the UPD subtype) seen on the depression/anxiety factor and the repetitive questioning factor. Those with PWS due to the deletion subtype more frequently endorse skin-picking items. But the magnitude of differences between genetic subtypes was not large. These findings are consistent with previous literature, which further validates the PWS Profile.
It will be very useful for the community to have this valid, psychometrically sound assessment tool to evaluate behavioral and emotional symptoms in individuals with PWS. Importantly, the PWS Profile has already demonstrated responsiveness to treatment in a previous clinical trial.2,3
The PWS Profile can be easily used in future clinical trials to evaluate the impact of medications and behavioral interventions not only on hyperphagia but also on the emotional and behavioral problems that are common in PWS. In addition, the profile can also be used to track the natural history of a broad range of PWS symptoms over time.
Thank you to everyone who participated in the PWS Global Registry and PATH for PWS study for their contribution to this important study!
