[Molecular diagnosis of Prader-Willi and Angelman syndromes: methylation, cytogenetics and FISH analysis].

Abstract

BACKGROUND:

The diagnosis of Prader-Willi and Angelman syndromes is difficult, since their phenotypic manifestations are variable and unspecific. The study of the methylation state of DNA in 15(q11-q13) using polymerase chain reaction, called methylation test, allows the diagnosis of most patients with Prader-Willi and Angelman syndromes, irrespective if the underlying molecular alteration is a deletion, uniparental disomy or a punctual imprinting mutation.

AIM:

To assess the effectiveness of methylation test in the diagnosis of Prader-Willi and Angelman syndromes.

PATIENTS AND METHODS:

Thirty seven cases with a presumptive diagnosis of Prader-Willi syndrome and 25 with the presumptive diagnosis of Angelman syndrome were studied. Methylation test was done in genomic DNA obtained from peripheral lymphocytes.

RESULTS:

Methylation test confirmed the clinical diagnosis in 11 of 37 patients with Prader Willi (30%) and 6 of 25 patients with Angelman syndrome (24%).

CONCLUSIONS:

Clinical criteria overestimate the diagnosis of Prader-Willi and Angelman syndromes. The initial diagnosis should be confirmed with the methylation test and, if necessary, with FISH that will detect most deletions in the region.

• Authors: L Santa María, B Curotto, F Cortés, C Rojas, M A Alliende
• Journal: Revista medica de Chile (Rev Med Chil) Vol. 129 Issue 4 Pg. 367-74 (Apr 2001) ISSN: 0034-9887 [Print] Chile
• Vernacular Title: Diagnóstico molecular de los síndromes de Prader-Willi y de Angelman: análisis de metilación, citogenética y FISH.
• PMID: 11413988 (Publication Type: English Abstract, Journal Article)

Topics

• Adolescent
• Adult
• Angelman Syndrome (diagnosis, genetics)
• Child
• Child, Preschool
• DNA Methylation
• Female
• Humans
• In Situ Hybridization, Fluorescence
• Infant
• Karyotyping
• Male
• Mutation
• Polymerase Chain Reaction
• Prader-Willi Syndrome (diagnosis, genetics)