Hormonal, metabolic and skeletal phenotype of Schaaf-Yang syndrome: a comparison to Prader-Willi syndrome

Abstract

This is the first analysis of the hormonal, metabolic and body composition phenotype of SYS. Our findings suggest that there is marked, but not complete overlap between PWS and SYS.

MAGEL2‐related disorders: A study and case series

“…Literature review yielded 23 articles and 1 Letter to the Editor pertaining to these syndromes, which are summarized in the Preferred Reporting Items for Systematic Reviews (PRISMA) diagram (Figure ) . We include a simplified summary of the patients' symptoms (Table ) and further summaries of all CHS and SYS patients to date (Table S1 in Appendix S1).…”

“…Literature review yielded 23 articles and 1 Letter to the Editor pertaining to these syndromes, which are summarized in the Preferred Reporting Items for Systematic Reviews (PRISMA) diagram ( Figure 2). 4,[7][8][9]14,15,[17][18][19][20][21][22][29][30][31][32][33][34][35][36][37][38] We include a simplified summary of the patients' symptoms (Table 1) and further summaries of all CHS and SYS patients to date (Table S1 in Appendix S1). In addition, tissue-specific symptomatic breakdowns for CHS, SYS and PWS are also included (Table S2 in Appendix S1).…”

“…17 Interestingly, in 2013, Schaaf et al reported a phenotype associated with truncating MAGEL2 mutations and noted that affected individuals had considerable phenotypic overlap with those affected by PWS, except that they also presented with arthrogryposis, autism spectrum disorder and, in subsequent reports, endocrine dysfunction, such as hypopituitarism. 4,[18][19][20][21] Based on its distinct genetic etiology in comparison to PWS, the syndrome was named Schaaf-Yang syndrome (SYS) (OMIM #615547). 19 Recently, mutations in MAGEL2 have been reported to be associated with additional clinical diagnoses.…”

Schaaf-Yang syndrome shows a Prader-Willi syndrome-like phenotype during infancy

“…Paternal deletions of this region result in Prader-Willi syndrome (PWS, OMIM #176270) [1,2]. It was recently reported that truncating variants in MAGEL2, one of the paternally expressed genes located in this region, caused Schaaf-Yang syndrome (SYS, OMIM #615547) [3][4][5][6][7][8][9][10]. SYS patients present with several symptoms typical of PWS, such as developmental delay, neonatal hypotonia, poor suck that requires special feeding techniques, and excessive weight gain.…”

“…SYS patients present with several symptoms typical of PWS, such as developmental delay, neonatal hypotonia, poor suck that requires special feeding techniques, and excessive weight gain. However, they also experience symptoms not typically seen in PWS, including arthrogryposis and autism spectrum disorder (ASD) [3][4][5][6][7][8][9][10]. Truncating variants in MAGEL2 cause severe arthrogryposis with reduced fetal movement resulting in perinatal death [11].…”