Chinese Siblings with Prader-Willi Syndrome Inherited from Their Paternal Grandmother

ABSTRACT

Background: Prader-Willi syndrome (PWS) is a complex neurobehavioral disorder causedby failure of expression of paternally inherited genes in the PWS region of chromosome 15.Case characteristics Two siblings who both met the inclusion criteria for clinical diagnosisof PWS during neonatal period. Outcome: Molecular genetic analysis demonstrated a 417-kb microdeletion within the 15q11.2 region inherited from siblings’ paternal grandmother,involving key genes of PWS, except for UBE3A, which may explain why their father andpaternal grandmother had a normal phenotype. Conclusion: The findings may be helpfulfor better understanding of the underlying mechanism of this rare imprinting defect