Smeets E, Schollen E, Moog U, Matthijs G, Herbergs J, Smeets H, Curfs L, Schrander-Stumpel C, Fryns JP. Rett syndrome in adolescent and adult females: clinical and molecular genetic findings. Am J Med Genet. 2003 Oct 15;122A(3):227-33. (SCI Impactfactor 7.774)

Jais JP, Knebelmann B, Giatras I, De Marchi M, Rizzoni G, Renieri A, Weber M, Gross O, Netzer KO, Flinter F, Pirson Y, Dahan K, Wieslander J, Persson U, Tryggvason K, Martin P, Hertz JM, Schroder C, Sanak M, Carvalho MF, Saus J, Antignac C, Smeets H , Gubler MC. X-linked alport syndrome: natural history and genotype-phenotype correlations in girls and women belonging to 195 families: a "European Community Alport Syndrome Concerted Action" study. J Am Soc Nephrol. 2003 Oct;14(10):2603-10.

Alders M, Jongbloed R, Deelen W, van den Wijngaard A, Doevendans P, Ten Cate F, Regitz-Zagrosek V, Vosberg HP, van Langen I, Wilde A, Dooijes D, Mannens M. The 2373insG mutation in the MYBPC3 gene is a founder mutation, which accounts for nearly one-fourth of the HCM cases in the Netherlands. Eur Heart J. 2003 Oct;24(20):1848-53

Moog U, Smeets EE, van Roozendaal KE, Schoenmakers S, Herbergs J, Schoonbrood-Lenssen AM, Schrander-Stumpel CT. Neurodevelopmental disorders in males related to the gene causing Rett syndrome in females (MECP2). Eur J Paediatr Neurol. 2003;7(1):5-12. Review. 

Peeters MW, Thomis MA, Claessens AL, Loos RJ, Maes HH, Lysens R, Vanden Eynde B, Vlietinck R, Beunen G. Heritability of somatotype components from early adolescence into young adulthood: a multivariate analysis on a longitudinal twin study. Ann Hum Biol. 2003 Jul-Aug;30(4):402-18.

Lambrechts D, Storkebaum E, Morimoto M, Del-Favero J, Desmet F, Marklund SL, Wyns S, Thijs V, Andersson J, Van Marion I, Al-Chalabi A, Bornes S, Musson R, Hansen V, Beckman L, Adolfsson R, Pall HS, Prats H, Vermeire S, Rutgeerts P, Katayama S, Awata T, Leigh N, Lang-Lazdunski L, Dewerchin M, Shaw C, Moons L, Vlietinck R, Morrison KE, Robberecht W, Van Broeckhoven C, Collen D, Andersen PM, Carmeliet P. VEGF is a modifier of amyotrophic lateral sclerosis in mice and humans and protects motoneurons against ischemic death. Nat Genet. 2003 Jul 6

Moog U, Smeets EE, van Roozendaal KE, Schoenmakers S, Herbergs J, Schoonbrood-Lenssen AM, Schrander-Stumpel CT. Neurodevelopmental disorders in males related to the gene causing Rett syndrome in females (MECP2). Eur J Paediatr Neurol. 2003;7(1):5-12. Review. 

Fagard RH , Loos RJ, Beunen G, Derom C, Vlietinck R. Influence of chorionicity on the heritability estimates of blood pressure: a study in twins. J Hypertens. 2003 Jul;21(7):1313-8.

Loos RJ, Verhaeghe J, De Zegher F, Beunen G, Derom C, Fagard R, Mathieu C, Vlietinck R. Markers for cardiovascular disease in monozygotic twins discordant for the use of third-generation oral contraceptives. J Hum Hypertens. 2003 Jul;17(7):481-5. 

Langendonck L, Claessens AL, Vlietinck R, Derom C, Beunen G. Influence of Weight-bearing Exercises on Bone Acquisition in Prepubertal Monozygotic Female Twins: A Randomized Controlled Prospective Study. Calcif Tissue Int. 2003 Jun;72(6):666-74.

Wehrens XH, Rossenbacker T, Jongbloed RJ, Gewillig M, Heidbuchel H, Doevendans PA, Vos MA, Wellens HJ, Kass RS. A Novel mutation L619F in the cardiac Na+ channel SCN5A associated with long-QT syndrome (LQT3): a role for the I-II linker in inactivation gating. Hum Mutat. 2003 May;21(5):552. 

Koppens PF, Smeets HJ, de Wijs IJ, Degenhart HJ. Mapping of a de novo unequal crossover causing a deletion of he steroid 21- hydroxylase (CYP21A2) gene and a non-functional hybrid tenascin-X (TNXB) gene.J Med Genet. 2003 May;40(5):e53.


Paulussen A, Matthijs G, Gewillig M, Verhasselt P, Cohen N, Aerssens J. Mutation analysis in congenital long QT syndrome - a case with missense mutations in KCNQ1 and SCN5A. Genetic Testing 2003 Spring;7(1):57-61.

Jongbloed RJ, Marcelis CL, Doevendans PA, Schmeitz-Mulkens JM, Van Dockum WG, Geraedts JP, Smeets HJ. Variable clinical manifestation of a novel missense mutation in the alpha-tropomyosin (TPM1) gene in familial hypertrophic cardiomyopathy. J Am Coll Cardiol. 2003 Mar 19;41(6):981-6.

Van Langen IM, Birnie E, Alders M, Jongbloed RJ, Le Marec H, Wilde AA. The use of genotype-phenotype correlations in mutation analysis for the long QT syndrome. J Med Genet. 2003 Feb;40(2):141-5.

Derom C, Derom R, Loos RJ, Jacobs N, Vlietinck R. Retrospective determination of chorion type in twins using a simple questionnaire. Twin Res. 2003 Feb;6(1):19-21.

Stalmans I, Lambrechts D, De Smet F, Jansen S, Wang J, Maity S, Kneer P, von der Ohe M, Swillen A, Maes C, Gewillig M, Molin DG, Hellings P, Boetel T, Haardt M, Compernolle V, Dewerchin M, Plaisance S, Vlietinck R, Emanuel B, Gittenberger-de Groot AC, Scambler P, Morrow B, Driscol DA, Moons L, Esguerra CV, Carmeliet G, Behn-Krappa A, Devriendt K, Collen D, Conway SJ, Carmeliet P. VEGF: a modifier of the del22q11 (DiGeorge) syndrome? Nat Med. 2003 Feb;9(2):173-82.


Henskens LH, Spiering W, Stoffers HE, Soomers FL, Vlietinck RF, de Leeuw PW, Kroon AA. Effects of ACE I/D and AT1R-A1166C polymorphisms on blood pressure in a healthy normotensive primary care population: first results of the Hippocates study. J Hypertens. 2003 Jan;21(1):81-6. 





Microdissection and gene specific PCR on single chromosomes identify Spinal Muscular Atrophy (SMA) carriers.
W. J. G. Loots1, J. C. F. M. Dreesen1, C. de Die-Smulders1, S. Rudnik-Schoneborn2, J. J. P. M. Geraedts1, B. J. M. Smeets1; 1academic hospital Maastricht,, Maastricht, Netherlands, 2Universitatsklinikum der RWTH, Aachen, Germany. Approximately 95% of all Spinal Muscular Atrophy (SMA)-patients carry a homozygous deletion of at least exon 7 of the survival motor neuron (SMNt) gene. The presence of (multiple copies of) a nearly identical centromeric homologue of this gene, SMNc, complicates the detection of this deletion in carriers. So far, quantitative PCR or haplotyping were the only methods by which SMA carriers could be identified, but these methods are not fully reliable, because of the variable copy number of genes and pseudogenes that may be present. We report the development of a new and direct approach to identify SMA carriers by microdissection of single copies of chromosome 5 followed by gene specific amplification of the SMN exon 7. In this study we included nine individuals with or without a heterozygous deletion in one of the SMNt genes. In total, 48 chromosome 5 pairs were tested blindly (two complete chromosome sets for each individual). Of these, 36 (75%) were of sufficient quality to be further analysed. Data obtained revealed that allelic drop out (ADO) occurred in 3% of all single chromosome samples. Genotyping of individuals proved to be 100% accurate as no discrepancies were found between the determined genotype and the actual genotype in all individuals tested. In conclusion, this new method allows reliable and efficient identification of SMNt exon 7 deletion carriers. However the described method is technically complex and it has to established if the method is sufficiently robust for routine diagnostics.


Gene expression profiles define mitochondrial pathology in yeast mutants and human disease.
H. Smeets1, L. Eijssen1, R. Mineri2, R. van Eijsden1, C. van den Burg1,3, R. Peeters4, I. De Coo5, H. Scholte5, E. Rubio3, M. Zeviani2, R. Vlietinck1, V. Tiranti2. 1) Dept Genetics & Cell Biol, Univ Maastricht, Maastricht, Netherlands; 2) Div Molec Neurogen, Nat Neurolog Inst "C.Besta", Milano, Italy; 3) Dept Pediatr, Academ Hosp Maastricht, Maastricht, Netherlands; 4) Dept Mathematics, Univ Maastricht, Maastricht, The Netherlands; 5) Depts Neurol & Biochem, Erasmus Medical Centre, Rotterdam, Netherlands. The applicability of mathematical techniques for microarray data analysis and the incorporation of background knowledge into this analysis was tested for the mitochondrial system in yeast and human mutants. Mathematical techniques were derived from basic statistics, clustering, discriminant analysis and principal component analysis (PCA). Background knowledge was incorporated for the yeast data by downloading website ontology annotations automatically. As test data we used the set from Hughes et al. (Cell 102: 109-126 (2000) or containing whole genome (6,000 genes) expression profiles of 300 (mostly) gene knockout experiments in yeast. PCA reduced the dimension of the data set significantly without losing much of the information and reduced noise as well. By subsequent discriminant analysis, we could distinguish mitochondrial gene knockouts from non-mitochondrial gene knockouts (cytoskeleton, cell membrane, cell wall, cytoplasm, lysosome/vacuole/ peroxisome). As a next step, we applied the same approach on Affymetrix GeneCHIP data (U133A) of a group of 18 fibroblast cell lines of patients with Leigh disease, caused by a Surf1-mutation and 11 controls. The Surf1-patients could be reliably distinguished from the controls by a group of 13 mainly cell structure and ribosomal genes. Untested samples, which were analysed next, were correctly classified by this system. It is not clear at this point if these classifiers reflect Surf1-specific pathology or are characteristic for mitochondrial pathology in general. Gene expression studies in patients with mtDNA caused Leigh (8 fibroblast lines with the T8993G/C or T9176C mutation) or other syndromes and patients with secondary mitochondrial pathology are currently being performed to solve this question.

Detection of genomic rearrangements in the MECP2 gene by MLPA analysis.
J. Herbergs1,3, C. Van Roozendaal1, E. Smeets1, D. Tserpelis1, C. De Die-Smulders1, A. Midro2, U. Moog1,3, C. Schrander-Stumpel1, H. Smeets1,3. 1) Clinical Genetics, Academic Hosp Maastricht, Maastricht, Netherlands; 2) Clinical Genetics, Medical University of Bialystok, Poland;; 3) GROW, Maastricht University, The Netherlands. Rett syndrome is an X-linked severe neurodevelopmental disorder predominantly affecting females. Genetic analysis of classical patients has shown that in approximately 80% of these cases the syndrome is caused by different mutations in the gene encoding methyl-CpG-binding protein-2 (MECP2).The routine DNA-diagnostic screening protocol mostly involves DHPLC, DGGE, SSCP or direct sequence analysis of the coding exons and immediate flanking intronic regions of the gene. These approaches however do not allow detection of gross rearrangements in the MECP2 gene. For this purpose we have analyzed 12 mutation-negative cases using a multiplex ligation-dependent probe amplification (MLPA, MRC-Holland) technique to allow the detection of deletions and/or duplications in the MECP2 gene. The tested cases involved 4 classical and 2 atypical Rett syndrome patients and a further 6 patients displaying some Rett-like suggestive symptoms. By means of this approach we identified gross rearrangements in 2 of the 4 analyzed classical Rett cases. In one case we observed a deletion of exon 3 and most of the coding region of exon 4. In the second case a duplication of exon 3 and the coding region of exon 4 was detected. Both rearrangement were subsequently verified and confirmed by Southern blot analysis. No aberrations were observed in any of the other cases. Our findings warrant further (MLPA) studies to establish the prevalence of large rearrangements in the MECP2 gene in mutation negative classical Rett syndrome cases. The MPLA technique could subsequently easily be implemented in the routine molecular screening protocol.