title: Comparing two diagnostic laboratory tests for Williams syndrome: fluorescent in situ hybridization versus multiplex ligation-dependent probe amplification.
abstract: Most people with Williams syndrome (WS) have a heterozygous 1.55 Mb deletion on chromosome 7q11.23. For diagnostic purposes, fluorescence in situ hybridisation (FISH) with commercial FISH probes is commonly used to detect this deletion. We investigated whether multiplex ligation-dependent probe amplification (MLPA) is a reliable alternative for FISH. The MLPA kit (SALSA P029) contains probes for eight genes in the WS critical region: FKBP6, FZD9, TBL2, STX1A, ELN, LIMK1, RFC2, and CYLN2. The experimental FISH assay that was used consists of four probes covering the WS critical region. A total number of 63 patients was tested; in 53 patients, a deletion was detected both with FISH and MLPA(P029), in 10 patients both techniques failed to demonstrate a deletion. In only one patient, a deletion was detected which was not previously detected by two commercial FISH probes. This patient appeared to carry a small, atypical deletion. We conclude that MLPA is a reliable technique to detect WS. Compared with FISH, MLPA is less time consuming and has the possibility to detect also smaller, atypical deletions and duplications in the WS critical region.
authors.affiliation: Department of Clinical Genetics, VU University Medical Center, 1007 MB Amsterdam, The Netherlands. a.vanhagen@Vumc.nl
authors.forename: Johanna M
authors.initials: JM
authors.lastname: van Hagen
authors.forename: Hubertus J F M M
authors.initials: HJ
authors.lastname: Eussen
authors.forename: Ron
authors.initials: R
authors.lastname: van Schooten
authors.forename: Josef N
authors.initials: JN
authors.lastname: van Der Geest
authors.forename: Gerardina C
authors.initials: GC
authors.lastname: Lagers-van Haselen
authors.forename: Cokkie H
authors.initials: CH
authors.lastname: Wouters
authors.forename: Chris I
authors.initials: CI
authors.lastname: De Zeeuw
authors.forename: Johan J P
authors.initials: JJ
authors.lastname: Gille
mesh_terms: D002897:Chromosomes, Human, Pair 7; D005145:Face / Q000002:abnormalities; D006801:Humans; D017404:In Situ Hybridization, Fluorescence / Q000379:methods*; D021141:Nucleic Acid Amplification Techniques / Q000379:methods*; D010641:Phenotype; D018980:Williams Syndrome / Q000175:diagnosis* / Q000235:genetics