Multidimensional Evaluation of Awareness in Prader-Willi Syndrome

An Exploratory Analysis on the 2D:4D Digit Ratio and Its Relationship with Social Responsiveness in Adults with Prader-Willi Syndrome

Prader-Willi syndrome (PWS) is a genetic disorder produced by a lack of expression of paternally derived genes in the 15q11-13 region. Research has generally focused on its genetic and behavioral expression, but only a few studies have examined epigenetic influences. Prenatal testosterone or the maternal testosterone-to-estradiol ratio (MaTtEr) has been suggested to play an important role in the development of the 'social brain' during pregnancy. Some studies propose the 2D:4D digit ratio of the hand as an indirect MaTtEr measure. The relationship between social performance and MaTtEr has been studied in other neurodevelopmental conditions such as Autism Spectrum Disorder (ASD), but to our best knowledge, it has never been studied in PWS. Therefore, our study aims to clarify the possible existence of a relationship between social performance-as measured using the Social Responsiveness Scale (SRS)-and MaTtEr levels using the 2D:4D ratio. We found that, as a group, PWS individuals have shorter index and ring fingers than the control group, but no significant difference in the 2D:4D ratios. The 2D:4D ratio showed a correlation only with Restricted Interests and Repetitive Behavior Subscale, where a positive correlation only for male individuals with PWS was found. Considering only PWS with previous GH treatment during childhood/adolescence (PWS-GH), index and ring fingers did not show differences in length with the control group, but the 2D:4D ratio was significantly higher in the right or dominant hand compared to controls.

A Review of Prader–Willi Syndrome

Prader–Willi Syndrome (PWS, OMIM #176270) is a rare complex genetic disorder due to the loss of expression of paternally derived genes in the PWS critical region on chromosome 15q11-q13. It affects multiple neuroendocrine systems and may present failure to thrive in infancy, but then, hyperphagia and morbid obesity starting in early childhood became the hallmark of this condition. Short stature, hypogonadism, sleep abnormalities, intellectual disability, and behavioral disturbances highlight the main features of this syndrome. There have been a significant number of advances in our understanding of the genetic mechanisms underlying the disease, especially discoveries of MAGEL2, NDN, MKRN3, and SNORD116 genes in the pathophysiology of PWS. However, early diagnosis and difficulty in treating some of the disease’s most disabling features remain challenging. As our understanding of PWS continues to grow, so does the availability of new therapies and management strategies available to clinicians and families.

Social Responsiveness and Psychosocial Functioning in Adults with Prader-Willi Syndrome

Although various studies have investigated symptoms of autism spectrum disorder (ASD) in Prader−Willi syndrome (PWS), little is known about the consequences of these symptoms, especially in psychosocial function. We aimed to explore ASD symptoms in adults with PWS with special attention to psychosocial functionality. This cross-sectional study included 26 adults (15 women) with PWS who attended a reference unit for rare diseases. Participants’ primary caregivers completed the Social Responsiveness Scale (SRS), and clinicians assessed multidimensional functioning with the Personal and Social Performance Scale (PSP). Impaired social responsiveness was identified in 20 (76.9%) participants, and manifest to marked difficulties in social functioning were identified in 13 (50%). Participants with impaired social responsiveness (SRS ≥ 60) had significantly worse scores in functionality measured with the PSP (U = 12.5; p = 0.009) and with three of the four PSP main areas. Moreover, scores for the Social Cognition domain of the SRS correlated positively with the Socially useful activities (p < 0.05) and Personal and social relationships (p < 0.01) main areas of the PSP. These results suggest that difficulties in social skills should be assessed in all psychosocial evaluations of patients with PWS.