Multiplex ligation-dependent probe amplification (MLPA) detects large deletions in the MECP2 gene of Swedish Rett syndrome patients.
Mutations in the methyl-CpG-binding protein-2 (MECP2) gene on Xq28 have been found to be a cause of Rett syndrome (RS). In a previous mutation screening, we found MECP2 mutations in 81% of Swedish classical Rett women. In this study, we have analyzed 22 patients for MECP2 deletions using multiplex-ligation-dependent probe amplification (MLPA). Clinically, 11 of the patients who were classical Rett women, 3 were forme fruste, 1 was congenital RS, and 7 were Rett variants. As inclusion criteria, we used DNA from patients in whom previous sequencing results showed no mutations in coding portions of the MECP2 gene. MLPA is a method based on multiplex PCR. In one PCR, as many as 40 probes are amplified with the same primers. The specificity of the amplification products is determined by the site-specific hybridization of each probe construct, prior to amplification. Each PCR product has a unique length, which makes it possible to identify it by size separation. In 3 of 11 (27%) classical Rett women, we detected large deletions in MECP2 using MLPA. All these patients had deletions covering two exons; in 2 cases the deletion involved exons 3 and 4 and, in one case, exons 1 and 2 were missing. In the forme fruste, congenital and Rett-variant patients, we found no large deletions. We have found that MLPA is useful when it comes to finding large deletions compromising whole exons in MECP2. Used as a complementary method to DNA sequencing, it revealed new MECP2 mutations in classical RS patients.
Department of Clinical Genetics, Göteborg University, Sahlgrenska University Hospital/East, Göteborg, Sweden. anna.erlandson@clingen.gu.se
Anna
A
Erlandson
Lena
L
Samuelsson
Bengt
B
Hagberg
Mårten
M
Kyllerman
Mihailo
M
Vujic
Jan
J
Wahlström
D002868:Chromosomal Proteins, Non-Histone / Q000235:genetics*; D015342:DNA Probes / Q000737:chemistry / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics*; D005091:Exons; D005260:Female; D006801:Humans; D051783:Methyl-CpG-Binding Protein 2; D012097:Repressor Proteins / Q000235:genetics*; D015518:Rett Syndrome / Q000235:genetics*; D017384:Sequence Deletion; D013548:Sweden
D002868:Chromosomal Proteins, Non-Histone; D015342:DNA Probes; D004268:DNA-Binding Proteins; C497392:MECP2 protein, human; D051783:Methyl-CpG-Binding Protein 2; D012097:Repressor Proteins