Comparative genomic hybridization on a microarray (microarray-CGH) allows to detect genomic chromosome imbalances. In order to assess its value to detect small chromosome imbalances observed in a clinical setting, using a DNA chip available commercially (Spectral Genomics, Houston, Texas, USA), we studied the DNA of 9 patients carrying a well characterized chromosome imbalance and the DNA of 11 patients where cytogenetic techniques such as high resolution banding karyotype, FISH using subtelomeric probes and comparative genomic hybridization on metaphase chromosomes conclude to a normal and/or balanced karyotype. A result was obtained for 19/20 patients. Failure of hybridization was observed for one patient. For all the other cases the sex of patients was correctly identified. Microarray-CGH was able to correctly diagnose the chromosome imbalance in 6/8 patients carrying such a defect i.e 9/11 imbalances (deletion or duplication) were detected. No chromosome imbalance was observed in 11 patients considered normal and/or balanced using cytogenetic techniques. Several clones were found to be polymorphic and required FISH studies to eliminate duplication or deletion. In conclusion, we think that this commercially available DNA chip might be useful to screen for chromosome imbalances. However, technical improvements are still necessary before using it in a clinical setting. Also, further studies are necessary to assess its sensitivity and specificity.

Chromosome Aberrations↗

PubMedDate not supplied

[Prenatal diagnosis of various hereditary blinding diseases].

The availability of more and more reliable obstetrical echographies makes now possible to screen fetuses for microphtalmies and anophtalmies. More over, by mean of linkage studies with DNA markers within a family, we can identify the women who will transmit X-linked diseases, and realize a prenatal diagnosis. This technology can be applied to the following ophthalmological diseases: the X-linked retinoschisis, the choroideremia, the ocular albinism, the Noorie disease, and recently the retinoblastoma. From now on, the use of such a technology which makes it possible to detect ophthalmological diseases in the fetuses, is posing ethical problems especially in case of diseases without any survival prognosis involvement.

Anophthalmos↗