Publications (5)28.59 Total impact
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Article: Array-based comparative genomic hybridisation identifies high frequency of cryptic chromosomal rearrangements in patients with syndromic autism spectrum disorders.
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ABSTRACT: Autism spectrum disorders (ASD) refer to a broader group of neurobiological conditions, pervasive developmental disorders. They are characterised by a symptomatic triad associated with qualitative changes in social interactions, defect in communication abilities, and repetitive and stereotyped interests and activities. ASD is prevalent in 1 to 3 per 1000 people. Despite several arguments for a strong genetic contribution, the molecular basis of a most cases remains unexplained. About 5% of patients with autism have a chromosome abnormality visible with cytogenetic methods. The most frequent are 15q11-q13 duplication, 2q37 and 22q13.3 deletions. Many other chromosomal imbalances have been described. However, most of them remain undetectable using routine karyotype analysis, thus impeding diagnosis and genetic counselling. 29 patients presenting with syndromic ASD were investigated using a DNA microarray constructed from large insert clones spaced at approximately 1 Mb intervals across the genome. Eight clinically relevant rearrangements were identified in 8 (27.5%) patients: six deletions and two duplications. Altered segments ranged in size from 1.4 to 16 Mb (2-19 clones). No recurrent abnormality was identified. These results clearly show that array comparative genomic hybridisation should be considered to be an essential aspect of the genetic analysis of patients with syndromic ASD. Moreover, besides their importance for diagnosis and genetic counselling, they may allow the delineation of new contiguous gene syndromes associated with ASD. Finally, the detailed molecular analysis of the rearranged regions may pave the way for the identification of new ASD genes.Journal of Medical Genetics 12/2006; 43(11):843-9. · 6.36 Impact Factor -
Article: Tiling path resolution mapping of constitutional 1p36 deletions by array-CGH: contiguous gene deletion or "deletion with positional effect" syndrome?
Journal of Medical Genetics 03/2005; 42(2):166-71. · 6.36 Impact Factor -
Article: NIPBL mutations and genetic heterogeneity in Cornelia de Lange syndrome.
Journal of Medical Genetics 01/2005; 41(12):e128. · 6.36 Impact Factor -
Article: Genome-wide screening using automated fluorescent genotyping to detect cryptic cytogenetic abnormalities in children with idiopathic syndromic mental retardation.
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ABSTRACT: Mental retardation (MR) is the most common developmental disability, affecting approximately 2% of the population. The causes of MR are diverse and poorly understood, but chromosomal rearrangements account for 4-28% of cases, and duplications/deletions smaller than 5 Mb are known to cause syndromic MR. We have previously developed a strategy based on automated fluorescent microsatellite genotyping to test for telomere integrity. This strategy detected about 10% of cryptic subtelomeric rearrangements in patients with idiopathic syndromic MR. Because telomere screening is a first step toward the goal of analyzing the entire genome for chromosomal rearrangements in MR, we have extended our strategy to 400 markers evenly distributed along the chromosomes to detect interstitial anomalies. Among 97 individuals tested, three anomalies were found: two deletions (one in three siblings) and one parental disomy. These results emphasize the value of a genome-wide microsatellite scan for the detection of interstitial aberrations and demonstrate that automated genotyping is a sensitive method that not only detects small interstitial rearrangements and their parental origin but also provides a unique opportunity to detect uniparental disomies. This study will hopefully contribute to the delineation of new contiguous gene syndromes and the identification of new imprinted regions.Clinical Genetics 09/2004; 66(2):122-7. · 3.13 Impact Factor -
Article: Microarray based comparative genomic hybridisation (array-CGH) detects submicroscopic chromosomal deletions and duplications in patients with learning disability/mental retardation and dysmorphic features.
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ABSTRACT: The underlying causes of learning disability and dysmorphic features in many patients remain unidentified despite extensive investigation. Routine karyotype analysis is not sensitive enough to detect subtle chromosome rearrangements (less than 5 Mb). The presence of subtle DNA copy number changes was investigated by array-CGH in 50 patients with learning disability and dysmorphism, employing a DNA microarray constructed from large insert clones spaced at approximately 1 Mb intervals across the genome. Twelve copy number abnormalities were identified in 12 patients (24% of the total): seven deletions (six apparently de novo and one inherited from a phenotypically normal parent) and five duplications (one de novo and four inherited from phenotypically normal parents). Altered segments ranged in size from those involving a single clone to regions as large as 14 Mb. No recurrent deletion or duplication was identified within this cohort of patients. On the basis of these results, we anticipate that array-CGH will become a routine method of genome-wide screening for imbalanced rearrangements in children with learning disability.Journal of Medical Genetics 05/2004; 41(4):241-8. · 6.36 Impact Factor