Array comparative genomic hybridization (array CGH) for detection of genomic copy number variants.

Array CGH for the detection of genomic copy number variants has replaced G-banded karyotype analysis. This paper describes the technology and its application in a clinical diagnostic service laboratory. DNA extracted from a patient's sample (blood, saliva or other tissue types) is labeled with a fluorochrome (either cyanine 5 or cyanine 3).

A new direction for prenatal chromosome microarray testing: software-targeting for detection of clinically significant chromosome imbalance without equivocal findings.

Purpose. To design and validate a prenatal chromosomal microarray testing strategy that moves away from size-based detection thresholds, towards a more clinically relevant analysis, providing higher resolution than G-banded chromosomes but avoiding the detection of copy number variants (CNVs) of unclear prognosis that cause parental anxiety. Methods.

Benefits and drawbacks of preimplantation genetic diagnosis (PGD) for reciprocal translocations: lessons from a prospective cohort study.

Preimplantation genetic diagnosis (PGD) using fluorescence in situ hybridisation probes was carried out for 59 couples carrying reciprocal translocations. Before treatment, 85% of pregnancies had resulted in spontaneous miscarriage and five couples had achieved a healthy live-birth delivery. Following treatment, 33% of pregnancies failed and 21 of 59 couples had a healthy live-born child.

Validation and implementation of array comparative genomic hybridisation as a first line test in place of postnatal karyotyping for genome imbalance.

Background: Several studies have demonstrated that array comparative genomic hybridisation (CGH) for genome-wide imbalance provides a substantial increase in diagnostic yield for patients traditionally referred for karyotyping by G-banded chromosome analysis. The purpose of this study was to demonstrate the feasibility of and strategies for, the use of array CGH in place of karyotyping for genome imbalance, and to report on the results of the implementation of this approach.

Results: Following a validation period, an oligoarray platform was chosen.

Preimplantation genetic diagnosis for a carrier of a Y;autosome translocation resulting in a healthy male offspring.

Objective: To demonstrate the feasibility of establishing a successful pregnancy for a carrier of a balanced Y;autosome translocation.

Design: Four locus-specific fluorescence in situ hybridization (FISH) probes, informative for the translocation, were identified and tested on peripheral lymphocyte metaphase chromosomes and interphase preparations from the translocation carrier and his partner.

Setting: National health service genetics center, cytogenetics laboratory, and assisted conception unit.