High-throughput analysis of subtelomeric chromosome rearrangements by use of array-based comparative genomic hypridization

Telomeric chromosome rearrangements may cause mental retardation, congenital anomalies, and miscarriages. Automated detection of subtle deletions or duplications involving telomeres is essential for high-throughput diagnosis, but impossible when conventional cytogenetic methods are used. Array-based comparative genomic hybridization (CGH) allows high-resolution screening of copy number abnormalities by hybridizing differentially labeled test and reference genomes to arrays of robotically spotted clones. To assess the applicability of this technique in the diagnosis of (sub)telomeric imbalances, we here describe a blinded study, in which DNA from 20 patients with known cytogenetic abnormalities involving one or more telomeres was hybridized to an array containing a validated set of human-chromosome–specific (sub)telomere probes. Single-copy-number gains and losses were accurately detected on these arrays, and an excellent concordance between the original cytogenetic diagnosis and the array-based CGH diagnosis was obtained by use of a single hybridization. In addition to the previously identified cytogenetic changes, array-based CGH revealed additional telomere rearrangements in 3 of the 20 patients studied. The robustness and simplicity of this array-based telomere copy-number screening make it highly suited for introduction into the clinic as a rapid and sensitive automated diagnostic procedure

CDK19 is disrupted in a female patient with bilateral congenital retinal folds, microcephaly and mild mental retardation

Microcephaly, mental retardation and congenital retinal folds along with other systemic features have previously been reported as a separate clinical entity. The sporadic nature of the syndrome and lack of clear inheritance patterns pointed to a genetic heterogeneity. Here, we report a genetic analysis of a female patient with microcephaly, congenital bilateral falciform retinal folds, nystagmus, and mental retardation. Karyotyping revealed a de novo pericentric inversion in chromosome 6 with breakpoints in 6p12.1 and 6q21. Fluorescence in situ hybridization analysis narrowed down the region around the breakpoints, and the breakpoint at 6q21 was found to disrupt the CDK19 gene. CDK19 was found to be expressed in a diverse range of tissues including fetal eye and fetal brain. Quantitative PCR of the CDK19 transcript from Epstein–Barr virus-transformed lymphoblastoid cell lines of the patient revealed ~50% reduction in the transcript (p = 0.02), suggesting haploinsufficiency of the gene. cdk8, the closest orthologue of human CDK19 in Drosophila has been shown to play a major role in eye development. Conditional knock-down of Drosophila cdk8 in multiple dendrite (md) neurons resulted in 35% reduced dendritic branching and altered morphology of the dendritic arbour, which appeared to be due in part to a loss of small higher order branches. In addition, Cdk8 mutant md neurons showed diminished dendritic fields revealing an important role of the CDK19 orthologue in the developing nervous system of Drosophila. This is the first time the CDK19 gene, a component of the mediator co-activator complex, has been linked to a human disease

Allocation of substance use disorder patients to appropriate levels of care: feasibility of matching guidelines in routine practice in Dutch treatment centres

AIMS: To examine the feasibility of implementing evidence-based guidelines for patient-treatment-matching to levels of care in two Dutch substance abuse treatment centres. DESIGN: Multi-centre observational follow-up study. SETTING: Two large substance abuse treatment centres (SATCs). PARTICIPANTS: All 4394 referrals to the two SATCs in 2003. MEASUREMENTS: Baseline patient characteristics needed for treatment allocation according to protocol, treatment allocation according to matching protocol, treatment allocation according to actual level of care (LOC) entered. ANALYSIS: Comparison of recommended and actual LOC entered. Evaluation of reasons for observed differences between recommended and actual LOC entered. FINDINGS: Data needed for treatment allocation according to protocol were available for 2269 (51.6%) patients. Data needed for evaluation of actual LOC entered were available for 1765 (40.2%) patients. Of these patients, 1089 (60.8%) were allocated according to protocol: 48.4% based on the guideline algorithm and 12.4% based on clinically justified deviations from this algorithm. The main reason for deviation was a different appraisal of addiction severity, made by the intake counsellor compared to the protocol. CONCLUSION: The feasibility of guideline-based treatment allocation is seriously limited due to inadequate data collection of patient characteristics and suboptimal guideline-based treatment allocation. As a consequence, only 24.4% of the patients could be evaluated as being matched properly to the treatment planned. The results indicate several barriers which limit the adequate implementation of patient-treatment-matching guidelines: problems in the infrastructure of data collection and storage and the inertia of intake staff who did not adhere to the guidelines for assessment and matchin