An Observational Study on Cephalometric Characteristics and Patterns Associated with the Prader–Willi Syndrome: A Structural Equation Modelling and Network Approach

Alin Viorel Istodor,Gratiela Georgiana Noja,Emanuel Bratu,Nicoleta Ioana Andreescu,Maria Puiu,Simona Sorina Farcas,Ciprian Roi,Alexandra Roi,Georgiana Moise,Laura-Cristina Rusu

doi:10.3390/app11073177

Abstract

Examining specific patterns of major cranio-facial alterations through cephalometric measurements in order to improve the Prader–Willi (PWS) syndrome diagnostic poses a major challenge of identifying interlinkages between numerous credentials. These interactions can be captured through probabilistic models of conditional independence between heterogeneous variables. Our research included 18 subjects (aged 4 to 28 years) genetically diagnosed with Prader–Willi syndrome and a healthy control group (matched age and sex). A morphometric and cephalometric analysis was performed upon all the subjects in order to obtain the needed specific data. We have, therefore, firstly deployed several integrated Gaussian graphical models (GGMs) to capture the positive and negative partial correlations and the intensity of the connections between numerous credentials configured to determine specific cranio-facial characteristics of patients with PWS compared to others without this genetic disorder (case-control analysis). Afterwards, we applied structural equation modelling (SEM) with latent class analysis to assess the impact of these coordinates on the prevalence of the Prader–Willi diagnostic. We found that there are latent interactions of features affected by external variables, and the interlinkages are strapping particularly between cranial base (with an important role in craniofacial disharmonies) and facial heights, as important characteristic patterns in determining the Prader–Willi diagnostic, while the overall patterns are significantly different in PWS and the control group. These results impact the field by providing an enhanced comprehensive perspective on cephalometric characteristics and specific patterns associated with Prader–Willi syndrome that can be used as benchmarks in determining the diagnostic of this rare genetic disorder. Furthermore, the two innovative exploratory research tools applied in this paper are very useful to the craniofacial field to infer the connections/dependencies between variables (particularly biological variables and genes) on cephalometric characteristics and specific patterns associated with Prader–Willi syndrome.

Highlights

Prader–Willi syndrome (PWS) is a complex, rare genetic disease, first described by Prader et al [1] in 1956 and characterized by a neurobehavior disorder
To further entail the importance of various facial-oral characteristics in determining the Prader–Willi syndrome diagnostic, in a case-control approach, we extended our research endeavor with a set of four structural equation modeling (SEM)
This research was conducted in the open conversation on the fundamental cranio-facial credentials and their interlinkages as essential milestones in determining the Prader–Willi syndrome diagnostic

Summary

Introduction

Prader–Willi syndrome (PWS) is a complex, rare genetic disease, first described by Prader et al [1] in 1956 and characterized by a neurobehavior disorder. The incidence of this rare genetic disease cannot be evaluated, but it is estimated to be 1 in. The genes that are imprinted are responsible for the RNA and the protein processing of hormones and neuroregulators. The majority of the documented cases (65–70%) occurred due to the deletion in chromosome 15, as many as 20–30% of the cases were caused by a uniparental disomy (maternal) of the chromosome 15, and 2–5% were due to an imprinting center defect [11]

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