Five novel locations of Neocentromeres in human: 18q22.1, Xq27.1∼27.2, Acro p13, Acro p12, and heterochromatin of unknown origin.

Since the first report in 1993, an ectopic centromere, i.e. neocentromere formation, has been reported in more than 100 small supernumerary marker chromosomes (sSMC), in 7 instances of centromere repositioning, and in about a dozen cases with more complex chromosomal rearrangements. Here we report 2 new cases with centromere repositioning and 3 neocentric sSMC consisting exclusively of heterochromatic material. Yet, no centromere formation was reported for the regions 18q22.1 and Xq27.1∼27.2 as it was observed in the 2 cases with centromere repositioning here; in both cases, cytogenetically an inversion was suggested. Two of the 3 neocentric sSMC were derived from a short arm of an acrocentric chromosome. The remainder neocentric sSMC case was previously reported and was stainable only by material derived from itself.

Delineation of a complex karyotypic rearrangement by microdissection and CGH in a family affected with split foot.

We report on a male patient and members of his family with additional material in chromosome 3. This derivative chromosome 3 was transmitted from his mother who had a complex rearrangement between chromosomes 2, 3, and 7. It was possible to delineate her chromosomal rearrangement by microdissection and reverse painting and to exclude these aberrations from being responsible for neonatal deaths and several abortions in this family. Two members of this family suffer from ectrodactyly or split hand/foot malformations (SHFM) of the feet which possibly correlates with the derivative chromosome 7 containing a breakpoint in the SHFM1 critical region involving several homeobox genes.

An easy and reliable procedure of microdissection technique for the analysis of chromosomal breakpoints and marker chromosomes.

Microdissection in combination with reverse painting fluorescence in-situ hybridization (FISH) is a very effective method to identify breakpoints and rearrangements of derived chromosomes and reveal the chromosomal origin of marker chromosomes. We describe an innovation that allows a convenient, fast and safe isolation of microdissected fragments as currently available protocols. The microdissected chromosomes are harvested in a collection drop located in a movable micropipette adjusted to a second micromanipulator under microscopic observation. We used this technique to analyze several cytogenetic aberrations. In order to evaluate the efficiency of our microdissection procedure, we compared the results obtained with microdissection probes made from only one fragment with those obtained with more than six microdissected fragments. In all cases, the single-fragment microdissections were sufficient to provide probes.

[Intracytoplasmic injection (ICSI) of cryopreserved testicular spermatozoa (Cryo-TESE): a retrospective study of the first 250 treatment cycles]. / Intrazytoplasmatische Injektion (ICSI) von kryokonservierten testikulären Spermatozoen (Kryo-TESE): Eine retrospektive Analyse der ersten 250 Behandlungszyklen.

It is reported on the results of 250 treatment cycles in which we carried out intracytoplasmic injections (ICSI) with frozen and thawed testicular spermatozoa (cryo-TESE). Up to July 1997 we treated 127 patients, 225 embryo transfers were performed (90%), and an average of 2.3 preimplantation embryos were transferred. This resulted in 53 clinical pregnancies, six patients aborted (11.3%). The pregnancy rate was 21.2% per treatment cycle, 23.5% per embryo transfer, and 41.7% per patient. This so called cumulative pregnancy rate is still about to rise, because 49 out of the 72 non-pregnant patients are still in our ICSI-program. Twenty-two children are born, 2 twins and 1 triplet. All children are healthy and without any major malformations. We conclude from these results that using cryopreserved testicular sperm for ICSI is an effective and successful approach for the treatment of severe testicular insufficiency. In comparison to the use of native testicular sperm with the necessity of repetitive testicular biopsies, cryopreservation is advantageous in many concerns (e.g. logistic, organisatoric and financial) and is therefore recommended for clinical routine.