Schaaf-Yang
syndrome (SYS) is a rare
genomic imprinting disorder caused by truncating
mutations in the paternally derived MAGE
family member L2 (MAGEL2)
allele. It is also responsible for
Prader-Willi syndrome, characterized by
neonatal hypotonia, developmental delay,
intellectual disability, respiratory distress in early infancy, and
arthrogryposis. More than 250 individuals with approximately 57 different molecular variants have been reported since 2013, but the
phenotype-
genotype association in SYS is not yet fully understood. Here, we describe the case of a Korean
patient diagnosed with SYS harboring a
mutation in the paternal
allele of MAGEL2 c.2895G>A, resulting in a
protein change of p.Trp965*. The
patient’s
phenotype included respiratory distress,
arthrogryposis,
hypotonia, and
feeding difficulty in the early neonatal period. Mild renal dysfunction and
hearing impairment were observed during infancy.