Prenatal diagnosis of Langer-Giedion Syndrome confirmed by BACs-on-Beads technique.

Langer-Giedion Syndrome (LGS), with characteristic phenotypic features including craniofacial dysmorphic signs, postnatal growth retardation and skeletal abnormalities, mental impairment, urogenital malformations and heart defects, is caused by partial deletions of the long arm of chromosome 8. We present a case of a female fetus with LGS. The diagnosis was molecularly proven with the BACs on Beads method at 32 weeks of gestation. To the best of our knowledge, prenatal recognition of that genetic defect had previously been made in only one case. Also, it has never been described before.

[Will the new molecular karyotyping BACs-on-Beads technique replace the traditional cytogenetic prenatal diagnostics? Preliminary reports]. / Czy nowa technika kariotypowania molekularnego BACs-on-Beads zastapi klasyczna cytogenetyczna diagnostyke prenatalna? Wyniki wstepne.

Recently several attempts have been made to introduce molecular karyotyping techniques into prenatal diagnosis. These methods can be used not only for the diagnosis of classical aneuploidies, but first of all they should be employed in the diagnostics of microaberrations, which are not revealed by low resolution methods of classical cytogenetics. The new method BACs-on-Beads is designed for quick detection of broad panel of aneuploidies and microdeletions, by the specified detection of deletions and duplications in the examined fetal DNA acquired from amniocytes. Prenatal diagnostics was performed with the use of BACs-on-Beads and classical amniocyte karyotyping simultaneously in a group of 54 pregnancies. This new method proved to be fully compatible with typical karyotyping in cultures of amniocytes in 98.2%. It was confirmed that the main advantage of this method is the possibility of quick diagnosis, within 48 hours, with much wider spectrum of detected anomalies when compared to classical methods. Contrary to other molecular karyotyping methods, the BACs-on-Beads technique is more economical, less time consuming and less complex equipment is needed than in case of other methods. We suppose that this technique can replace classical karyotyping methods in the near future.