Extra structurally abnormal chromosomes (ESACs)--presentation of 10 new cases

BACKGROUND

The goal of the presented studies as a retrospective reliability assessment of classical banding cytogenetic studies and of prognosing epicrises in a group of 14 cases, affected with additional marker chromosomes.

MATERIAL AND METHODS

Having collected the study material from peripheral blood, by means of trophoblast biopsy or amniocentesis, cytogenetic preparations were obtained, allowing for pre- or postnatal evaluation of the karyotype. A panel of auxiliary cytogenetic techniques accompanied the routine CTG protocol.

RESULTS

In a group of 6875 persons with recommendations to pre- or postnatal cytogenetic diagnostics, 14 (0.2%) cases of ESACs were diagnosed. In 5 cases of DA/DAPI(+) inv dup (15) as observed. A presence of polymorphic interstitial RHG(+) band was found within the marker chromosome. The measured size of that band allowed associating it with either the presence or the absence of pathological signs. In 9 cases of ESACs, DA/DAPI(-), the application of banding techniques (NOR and CBG) allowed to discover bisatellite heterochromatic ESACs in 6 cases (2 non-mosaic and 4 mosaic). In three other mosaic and non-satellite cases of ESACs, a 'genetic inactivity' of the marker chromosome was observed in one case, while a 'genetic activity' was ascertained in two cases. The 'activity' of marker chromosomes was studied by means of replication banding techniques.

CONCLUSIONS

At the time of the outburst of molecular techniques, still up-to-date is the use of classical banding techniques and of the replication techniques, allowing DNA replication kinetics studies at the level of single band.

Cytogenetic and molecular identification of a de novo direct duplication of the long arm of chromosome 4(q21.3-->q31.3)

We report on a 3-year-old boy with moderate developmental retardation, microcephaly, and malformations of ears, lids, mouth, and thumbs. Cytogenetic analysis demonstrated a direct duplication of chromosome subregion 4(q21.3-->q31.3). Confirmation of this specific rearrangement was performed by fluorescent in situ hybridization (FISH) with a chromosome painting probe and by means of quantitative Southern hybridization with DNA probes localized within the chromosome 4 region presumed to be duplicated.

De novo direct tandem duplication of the short arm of chromosome 7(p21.1-p14.2)

We report on a 6-year-old boy with moderate developmental retardation and unusual dermatoglyphics. Cytogenetic analysis demonstrated a duplication of chromosome sub-region 7p21.2-p14.2. Confirmation of the specific duplicated region was determined by quantitative Southern blotting by using a DNA fragment previously localized to the portion of chromosome 7 thought to be duplicated. This patient did not have the internal malformations seen with other dup(7p) patients.

Recurrences after surgical treatment of patients with post-thrombotic syndrome of the lower extremities

A Linton flap operation was performed in 148 patients with post-thrombotic syndrome of the lower extremities. One-hundred and five patients were followed up from 6 months to 10 years and 14.5% of cases had recurrent ulcers. The most common causes of recurrence was further deep venous thrombosis or remaining incompetent perforating veins. All patients with a recurrence of their ulcer had a further operation and incompetent perforating veins were ligated and divided with good clinical results.