title: Improved testing for CMT1A and HNPP using multiplex ligation-dependent probe amplification (MLPA) with rapid DNA preparations: comparison with the interphase FISH method.
abstract: Charcot-Marie-Tooth disease type 1A (CMT1A) and hereditary neuropathy with liability to pressure palsies (HNPP) are the two most common peripheral neuropathies, with incidences of about 1 in 2,500. Several techniques can be used to detect the typical 1.5-Mb duplication or deletion associated with these respective conditions, but none combines simplicity with high sensitivity. MLPA is a new technique for measuring sequence dosage. We have assessed its performance for the detection of the specific 1.5-Mb duplication/deletion by prospectively testing 50 patients referred with differential diagnoses of CMT or HNPP. Probes were designed to evaluate the TEKT3, PMP22, and COX10 genes within the CMT1A/HNPP region. We have compared the results with our existing fluorescence in situ hybridization (FISH) assay, which was performed in parallel. There was concordance of results for 49 patients. Of note, one patient showed an intermediate multiplex ligation-dependent probe amplification (MLPA) result with an abnormal FISH result, which is consistent with mosaicism. The assay works equally well with either purified DNA or rapid DNA preparations made by direct cell lysis. The use of the latter significantly reduces the cost of the assay. MLPA is a sensitive, specific, robust, and cost-effective technique suitable for fast, high-throughput testing and offers distinct advantages over other testing methods.
authors.affiliation: Genetic Health Services Victoria and Murdoch Childrens Research Institute, University of Melbourne Department of Paediatrics, Royal Children's Hospital, Parkville, Australia. howard.slater@ghsv.org.au
authors.forename: Howard
authors.initials: H
authors.lastname: Slater
authors.forename: Damien
authors.initials: D
authors.lastname: Bruno
authors.forename: Hua
authors.initials: H
authors.lastname: Ren
authors.forename: Phung
authors.initials: P
authors.lastname: La
authors.forename: Trent
authors.initials: T
authors.lastname: Burgess
authors.forename: Louise
authors.initials: L
authors.lastname: Hills
authors.forename: Sara
authors.initials: S
authors.lastname: Nouri
authors.forename: Jan
authors.initials: J
authors.lastname: Schouten
authors.forename: K H Andy
authors.initials: KH
authors.lastname: Choo
mesh_terms: D002607:Charcot-Marie-Tooth Disease / Q000235:genetics; D004247:DNA / Q000235:genetics* / Q000302:isolation & purification*; D015342:DNA Probes / Q000235:genetics*; D017353:Gene Deletion; D018628:Gene Dosage; D020440:Gene Duplication; D015417:Hereditary Sensory and Motor Neuropathy / Q000235:genetics*; D006801:Humans; D017404:In Situ Hybridization, Fluorescence / Q000379:methods*; D007399:Interphase / Q000235:genetics*; D022521:Ligase Chain Reaction / Q000379:methods*; D009185:Myelin Proteins / Q000235:genetics; D021141:Nucleic Acid Amplification Techniques / Q000379:methods*; D011446:Prospective Studies; D011506:Proteins / Q000235:genetics*
chemical_list: C109561:CDRT1 protein, human; D015342:DNA Probes; D009185:Myelin Proteins; C073687:PMP22 protein, human; D011506:Proteins; D004247:DNA