Trisomy 8 mosaicism in chorionic villus sampling: Case report and counselling issues

We report an unusual case involving chorionic villus sampling (CVS) and trisomy 8 mosaicism. CVS showed a normal direct preparation while the culture showed mosaicism for trisomy 8. Subsequent amniocentesis revealed only normal chromosomes. A peripheral blood culture after birth revealed low-level trisomy 8 mosaicism. The patient appeared phenotypically and developmentally normal at 30 months of age. We conclude that prenatal counselling for similar cases needs to include the rare but real possibility that chromosome mosaicism detected prenatally may be found postnatally with largely unknown consequences. Secondly, low-level chromosomal mosaicism may be more common than previously recognized. Thirdly, very low-level trisomy 8 mosaicism may be compatible with a normal phenotype but long-term follow-up is required. And lastly, the use of fetal blood sampling is questionable in these cases because the phenotype may not be accurately predicted. Further studies of such cases are needed to address these important and unanswered issues, including the potential implication of mosaicism on academic performance and cognitive functioning.     

A pipette method for rapid karyotyping in prenatal diagnosis

The 'pipette method' is introduced as a method of prenatal diagnosis which is in competition with the 'in situ' and the 'trypsinization' technique. It is sufficiently standardized for routine diagnosis and the banding techniques currently used in prenatal diagnosis (G, Q, C-banding and NOR) have been adapted for it. In 180 cases from 27 different centres, the 'pipette method' was employed for chromosomal harvesting in order to save time. An average of 6·6 days was taken to achieve a result. There was a pathological karyotype in 28 cases (16·1 per cent) and this high proportion can be related to cases where ultrasound scan has led to a diagnosis of 'suspected chromosomal abnormality'. This technique is also of use in advanced stages of pregnancy. The early recognition of the fetal karyotype can contribute to the future management of the pregnancy. The 'pipette method' can also be used in chromosomal harvesting of tumour cells and fibroblast cultures.     

Probable exclusion of juvenile neuronal ceroid lipofuscinosis in a fetus at risk: An interim report

In a family with two children affected by juvenile neuronal ceroid lipofuscinosis (JNCL) an attempt was made at the prenatal diagnosis of the disorder. The following tissues from the fetus at risk were investigated by electron microscopy and were found to be free of fingerprint profiles and curvilinear bodies, typical for JNCL: uncultivated amniotic fluid cells, lymphocytes isolated from fetal blood, and fetal skin biopsy specimens. The child was born at the 34th week of gestation and was clinically normal at the age of 15 months. Postnatally, lymphocytes (isolated at the age of 6 and 15 months) and skin tissue (taken at the age of 15 months) were found to be morphologically normal. It is highly unlikely that the child is affected but definite proof of the absence of JNCL remains difficult at this age.     

Abschätzung des umweltchemischen und ökotoxikologischen Verhaltens von Stoffen durch computergestützte Analyse von Struktur und Verhalten sowie von Struktur und Wirkung

Risk assessment of chemicals requires comprehensive data material, which often is not available. To provide substitutes for the lacking experimental ecotoxicological and physico-chemical data, a software-system (SAR-System) has been developed comprising more than 90 estimation models for relevant endpoints. The approach is based on quantitative structure-activity relationships (QSAR). Two major aspects characterize the SAR-System:

1. The implemented models were tested for their validity and application range.
2. The QSARs are accessible by a menu-driven programme package.

The following endpoints are included: Thysico-Chemical Data: 1-Octanol/water-partition-coefficient log P_ow, vapour pressure, water solubility, pK_a-value, boiling point Biological Data: Toxicity towards fish, daphnia, tetrahymenae, algae, bacteria and mammals, mutagenicity. Distribution: soil sorption, bioconcentration, Henry-Constant, Mackay (Level I). Degradation: photodegradation, biodegradability.