Overview of genetic testing in Prader-Willi syndrome

Introduction Prader-Willi syndrome (PWS) is a complicated neurodevelopmental genetic disorder stemming from the loss of expression of imprinted genes within the 15q11-q13 region. It is characterized by impaired hypothalamic development and function. Infants with PWS typically present hypotonia and feeding difficulties, which in later stages of childhood progress to hyperphagia, obesity, and endocrine dysfunctions. However, early diagnosis and treatment have proven effective in mitigating obesity and related co-morbidities in patients with PWS. Moreover, the precise molecular classification of PWS is crucial to tailor the appropriate treatment strategies and provide valuable genetic counseling.Areas covered This review contains various conventional and novel PWS diagnostic methods, assessing each method's underlying mechanisms, advantages and disadvantages. Furthermore, our review presents a genetic testing workflow for PWS diagnosis and explores promising techniques for newborn and prenatal screening, which facilitate early diagnosis and intervention. This review synthesizes pertinent studies from 1990 to 2022, gathered from databases including PubMed, Web of Science, EBSCO, and Cochrane.Expert opinion Starting with MS-MLPA is the most efficient way to detect underlying genetic mechanisms. However, it is essential to note that certain rare instances, such as balanced chromosomal rearrangements, may require complementary diagnostic techniques to identify accurately.