[Female Preterm Monozygotic Twins Discordant for Fetal Megacystis due to Cloacal Dysgenesis After Conception by Intracytoplasmatic Sperm Injection - Case Report and Review of Literature]. / Monozygote, weibliche Zwillingsfrühgeborene diskordant für das seltene, schwere Fehlbildungssyndrom einer fetalen Megazystis mit Kloakenfehlbildung nach künstlicher Befruchtung ­ Fallbericht und Literaturübersicht.

Monozygotic twins were previously regarded as "identical". By now an increasing number of case reports of monozygotic but discordant twins have been reported, and therefore discordance between monozygotic twins is being investigated intensively. We report a case of female preterm monozygotic twins who were discordant for fetal megacystis due to cloacal dysgenesis. Pregnancy was achieved after intracytoplasmatic sperm injection and transfer of 2 embryos. By the first trimester fetal megacystis with consecutive oligohydramnios and hypoplasia of the lungs was diagnosed. Both foetuses had normal karyotypes. After delivery at 25+3 weeks of gestation due to premature labour, the affected child was treated palliatively and died within 2 hours. In the postmortem physical examination, a cloacal dysgenesis was detected. In the male foetus, megacystis is typically caused by obstructive uropathy. In the rarely affected female foetus, it usually results from complex urogenital malformations like cloacal dysgenesis which originates from disruption during gastrulation. We identified 10 case series of mono- or dizygotic twins who were discordant either for fetal megacystis or for cloacal dysgenesis. Issues like conception, zygosity, sex, karyotype and aetiology of fetal megacystis were not reported in all cases. Discordance between monozygotic twins for structural birth defects is closely linked to the twinning process itself. Assisted reproduction is said to generate a higher rate of monozygotic twin pregnancies and to be responsible for a higher prevalence of chromosomal aberrations or congenital malformations. With regard to conception, zygosity, sex, karyotype and combination of malformations, our case is unique.

Transient change in GABA(A) receptor subunit mRNA expression in Lurcher cerebellar nuclei during Purkinje cell degeneration.

BACKGROUND: Lurcher mice suffer from a complete Purkinje cell (PC) loss in the first four postnatal weeks. Parallel to this degeneration, GABAergic synapses in the deep cerebellar nuclei (DCN), the major recipient of the inhibitory PC projection, increase synaptic conductance. Here, we further investigated this phenomenon, using real-time RT-PCR to assess GABAA receptor subunit gene expression during PC degeneration. RESULTS: We observed a specific reduction in gamma2 subunit gene expression, while alpha1-5, beta1-2, gamma1,3 and delta subunits were unaffected. We made two further specific findings. First, the difference in gene expression was shown in tissue from DCN only. Neither the hippocampus nor coronal sections through the forebrain showed such effects. Furthermore, the involvement of different levels of corticosterone, a possible humeral trigger for differences in gene expression, could be excluded. Second, like the known potentiation of GABAergic synapses, the gamma2 down-regulation was present only after the onset of degeneration at p14. The difference in gamma2 mRNA expression, however, appeared transient, since it was no longer detectable in adult Lurcher mice. CONCLUSION: In conclusion, the down-regulation of gamma2 subunits may be related to differences in synaptic efficacy and, as such, may reflect the initial phase of adaptive responses of DCN tissue to massive GABAergic deafferentation. Its transient course, however, does not support the idea that modulations in GABAergic transmission are at the basis of the well-known DCN-based functional benefit of Lurcher mice present throughout their life.