Is angelman syndrome an alternate result of del(15)(qllql3)?

Abstract

Two unrelated females, age 15 and 5 years respectively, were studied cytogenetically because of severe mental retardation, seizures and ataxia‐like incoordination. A similar deletion of the proximal long arm of chromosome 15 was found in both patients. Re‐evaluation showed no voracious appetite or obesity; normal size of hands and feet, minimal to no hypotonia by history or examination and facial features not typical of the Prader‐Willi syndrome. However, the facial appearance of the girls was similar to each other with mild hypertelorism. The similarity of these girls and dissimilarity to Prader‐Willi syndrome suggest a different syndrome, perhaps the result of deletion of a different segment of 15q. The findings of ataxic‐like movements, frequent, unprovoked and prolonged bouts of laughter and facial appearance are more compatible with the diagnosis of Angelman syndrome.