Type and frequency of chromosome aberrations in 781 couples undergoing intracytoplasmic sperm injection.

Cytogenetic investigations were performed in 781 couples prior to intracytoplasmic sperm injection (ICSI) because of severe male infertility or fertilization failures in previous in-vitro fertilization attempts. Out of these 1562 patients, 1012 had a normal karyotype without any aberrations (64.8%), 204 patients had an abnormal karyotypes (13.1%). These chromosome aberrations included constitutional aberrations (4.4%), fragile sites of autosomes (3.0%), low level mosaicism of sex chromosomes (4.0%) and secondary structural chromosome aberrations (4.2%). Combinations of different types of abnormalities were stated. Another 346 patients (22.1%) showed single cell aberrations; the significance of these is unclear at the moment. Constitutional chromosome aberrations were detected in 69 patients. The following chromosome aberrations were observed: 35 sex chromosomal aberrations (comprising hyperploidies of X or Y chromosomes, mosaicisms and derivative X and Y chromosomes), 34 autosomal aberrations including 14 reciprocal translocations, five Robertsonian translocations, six inversions, one marker chromosome, one trisomy 18 mosaicism and seven other structural aberrations. Three autosomal regions showed fragile sites: 6q13 in 2.9% of the patients, 17p12 and 10q24 in 0.05% each. In conclusion, our data show that a high number of infertile couples in an ICSI programme are affected by chromosome aberrations which occur in both sexes. It is suggested that a chromosomal analysis should be performed on both partners before ICSI treatment is initiated.

Frequent 4-bp deletion in exon 9 of the SMAD4/MADH4 gene in familial juvenile polyposis patients.

Familial juvenile polyposis (FJP) is a hamartomatous polyposis syndrome characterized by the appearance of juvenile polyps in the gastrointestinal tract. Patients with this syndrome are at an increased risk for cancer of the colon, stomach, and pancreas. Recently, germline mutations in the SMAD4/DPC4 gene (official symbol MADH4) have been found in the majority of patients suffering from FJP. We have examined 11 unrelated patients with FJP for MADH4 germline mutations by direct sequencing of genomic DNA encompassing all 11 exons of the gene. Besides a novel mutation (959-960delAC at codon 277, exon 6) in one patient, we observed a 4-bp deletion (1372-1375delACAG) in exon 9 in two unrelated patients. Examination with microsatellite markers flanking MADH4 supports an independent origin of the mutation in these two families. The same 4-bp deletion in exon 9 has previously been described in three out of nine patients examined for MADH4 mutations. Our results combined with these previous data demonstrate that a unique 4-bp deletion in exon 9 of MADH4 accounts for about 25% of all FJP cases and that other MADH4 mutations occur in an additional 15% of patients. Genes Chromosomes Cancer 25:403-406, 1999.

Genetic counseling in a patient with XXY/XXXY/XY mosaic Klinefelter's syndrome: estimate of sex chromosome aberrations in sperm before intracytoplasmic sperm injection.

OBJECTIVE: To report the sex chromosome aberrations in the sperm of a patient with mosaic Klinefelter's syndrome before ICSI. DESIGN: Case report. SETTING: Institute of Human Genetics, University Hospital PATIENT(S): A patient with an XXY/XXXY/XY mosaic Klinefelter's syndrome and extreme oligozoospermia. INTERVENTION(S): Skin biopsy, buccal smear, hair root sampling, and semen sampling. MAIN OUTCOME MEASURE(S): The karyotypes of three additional somatic cell systems and the ratio of sex chromosome aberrations in sperm. RESULT(S): After two-color fluorescence in situ hybridization of 202 interphase sperm nuclei, both the proportion of hyperhaploid 24, XY and 25, XXY sperm (5.0% and 0.5%, respectively) and of hyperhaploid 24, XX sperm (2.0%) were elevated. In contrast with peripheral lymphocytes, 93.9% of which showed sex chromosome aberrations, in the present patient only 7.5% of sperm proved to be hyperhaploid with an extra sex chromosome. CONCLUSION(S): The determination of sex chromosome aberrations in the sperm of a patient with mosaic Klinefelter's syndrome may provide additional information to estimate the transmission risk to his offspring.

[Experience and problems with biochemical differentiation of Enterobacteriaceae with microtiter plates]. / Erfahrungen und Probleme mit der biochemischen Differenzierung von Enterobacteriaceae in Mikrotiterplatten.

A self-made miniaturized test system for the biochemical identification of enterobacteriaceae in microtitre plates has been examined. Special emphasis was laid on easy and unequivocal interpretation of the reactions. This was achieved among other things by including further sugar fermentations. Applying a corresponding reaction matrix it is possible to get clear identifications, even in the case of missing test results. The performed tests show the usefulness of our test system.

[Increased yields of insulin by recycling of non-combined insulin chains]. / Erhöhte Insulinausbeuten durch "Recycling" der nichtkombinierten Ketten.

The yield of insulin by the combination of reduced A and B chains is increased from 15% to 33-34% if the non-insulin-containing fractions of the gel filtration are isolated and used for further combinations (recycling). Crude insulin recovered by gel filtration can be highly purified by preparative high-performance liquid chromatography. Lower yields of insulin were obtained on recombination of chains which had been recycled five times or more. Sulfur analyses show a loss of cystine sulfur. The occurrance of lanthionine and lysinoalanine indicates an alkaline destruction of cystine/cysteine during the repeated combination steps.

[An improved method for the combination of modified insulin chains (author's transl)]. / Eine verbesserte Methode der Kombination von Insulinketten zur Darstellung von Insulinanalogen.

A procedure is described in which the yields of the combination of insulin A and B chains, especially of modified chains, are increased. The chains are reduced simultaneously in 8M urea buffer at pH 8.6 with 2-mercaptoethanol. The thiol chains are not isolated but transferred to the oxidation buffer at pH 10.6 by means of gel chromatography on Sephadex G-25. During the chromatography about 50% of the tetrathiol A chain is oxidized specifically to a dithiol A chain disulphide, in which presumably the 6,11-disulphide ring is closen. Generally we observed that the combination yields of modified A or B chains are lower than the yields of combinations of unmodified A or B chains. It seems that there is a correlation between the biological activity of the analogue and the yield obtained by the recombination of the chains.