Syndrome de Di George, étude rétrospective de 52 cas

[Persistence of the 5th aortic arch associated with interruption of the aortic arch]

We report a case of persistence of the 5th aortic arch associated with total interruption of the aortic arch. This clinical case shows the diagnostic pitfall of the persistence of the 5th aortic arch and its beneficial hemodynamic effect. Preoperative clinical picture was misleading, due to the persistence of femoral pulses and clinical signs of left-to-right shunt via a wide ductus arteriosus. The diagnosis was intraoperatively adjusted on the basis of blood pressure monitoring using catheter placed into the femoral artery.

Diagnostic applications of fluorescence in situ hybridization

BACKGROUND

Fluorescence in situ hybridization (FISH) assays are indispensable in diagnostics and research. Routine application of this so-called molecular cytogenetic technique on human chromosomes started in 1986. Since then, a huge variety of different approaches for chromosomal differentiation based on FISH has been described. It was established to characterize marker chromosomes identified in conventional banding analysis as well as cryptic rearrangements not resolved by standard cytogenetics.

OBJECTIVE/METHOD

Even though molecular cytogenetics, like banding cytogenetics for almost 40 years, is often called dead now, it offers unique possibilities of single cell analysis. Thus, a review is presented here on the available diagnostic-relevant FISH methods and probe sets applied in routine pre- and postnatal clinical as well as tumor cytogenetics.

CONCLUSION

Molecular cytogenetics is a fast, straightforward and reliable tool that is indispensable in cytogenetic diagnostics. It is and will continue to be of high clinical impact in diagnostics, especially in the overwhelming majority of routine cytogenetic laboratories that cannot afford and do not need high-throughput chip-based platforms for their daily work.

Mapping cortical thickness in children with 22q11.2 deletions

The 22q11.2 deletion syndrome (velocardiofacial/DiGeorge syndrome, 22q11.2DS) involves cardiac and craniofacial anomalies, marked deficits in visuospatial cognition, and elevated rates of psychosis. Although the mechanism is unknown, characteristic brain alterations may predispose to development of psychosis and cognitive deficits in 22q11DS. We applied cortical pattern matching and new methods for measuring cortical thickness in millimeters to structural magnetic resonance images of 21 children with confirmed 22q11.2 deletions and 13 demographically matched healthy comparison subjects. Thickness was mapped at 65 536 homologous points, based on 3-dimensional distance from the cortical gray-white matter interface to the external gray-cerebrospinal fluid boundary. A pattern of regionally specific cortical thinning was observed in superior parietal cortices and right parietooccipital cortex, regions critical for visuospatial processing, and bilaterally in the most inferior portion of the inferior frontal gyrus (pars orbitalis), a key area for language development. Several of the 30 genes encoded in the deleted segment are highly expressed in the developing brain and known to affect early neuronal migration. These brain maps reveal how haploinsufficiency for such genes can affect cortical development and suggest a possible underlying pathophysiology of the neurobehavioral phenotype.