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Due to the heterogeneity of these disorders, the diagnosis of acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL) requires a broad spectrum of laboratory techniques: cytomorphology, immunophenotyping, chromosome banding analysis, fluorescence in situ hybridization, and molecular genetics. The cytomorphological leukemia subtypes can be indicative for distinct genetic alterations and contribute to the guidance of the further diagnostic process. Immunophenotyping allows to define the hematological lineage and to characterize the leukemia-associated immunophenotype as basis for follow up investigation. Cytogenetic alterations and molecular mutations are essential for the correct classification of cases and for prognostication. Molecular markers are helpful to define the minimal residual disease load after the achievement of hematological complete remission. In cases of hypocellular AML or in case of bone marrow necrosis, histopathology in combination with immunohistochemistry is of importance. Hierarchies between the different techniques catalyze the workflow in the laboratory and allow a rapid diagnosis and classification of the leukemia cases.

The multistep development of malignant tumors with increasing accumulation of genetic alterations from preneoplastic lesions to invasive carcinoma is an accepted model of carcinogenesis. Urothelial carcinoma of the bladder and upper urinary tract is an interesting model system to study tumor development and progression. There is both clinical and molecular evidence that urothelial carcinoma can be divided in two groups with different characteristics: 1) well differentiated genetic stable and mostly superficial papillary tumors with frequent recurrence and low progression risk and 2) poorly differentiated mostly solid and invasive tumors with a high number of genetic alterations. The aim of the studies summarized in this manuscript were: 1) to identify genetic changes with importance for urothelial carcinogenesis by investigation of preneoplastic and early neoplastic urothelial lesions, 2) to define molecular markers for progression of papillary carcinoma, and 3) to investigate the importance of microsatellite instability and mismatch repair defects for development of tumors of the upper urinary tract which are frequently found within the HNPCC syndrome. The investigation of urothelial hyperplasias, dysplasias and carcinoma in situ by deletion mapping (LOH analysis), FISH, CGH and mutation detection revealed that urothelial hyperplasias are precursors of papillary bladder tumors and flat dysplasias can be regarded as precursors of solid bladder cancers. In bladder cancer patients, there are genetic alterations already detectable in histologically inconspicous urothelium. The investigation of papillary bladder cancers for progression-related genetic alterations showed that mutations in the wnt pathway genes APC and beta-Catenin do not play an important role in urothelial carcinogenesis. Instead, the expression of the antagonistic wnt-related genes WIF-1 and sFRPI is strongly reduced in bladder cancer and associated with poor prognosis in papillary tumors. Loss of sFRP1 expression is not due to gene mutation but to epigenetic inactivation by promoter hypermethylation and is related to deletions at chromosome 8p12. In contrast to bladder cancers, tumors of the ureter and renal pelvis develop through a different genetic pathway in 30% of cases. The loss of mismatch repair proteins (hMSH2, hMLH1 or hMSH6) leads to a mutator phenotype with accumulation of genetic alterations in multiple repetitive sequences (microsatellite instability, MSI). MSI-positive tumors were predominantly located in the ureter and showed a lower tumor stage and grade and papillary and frequently inverted growth pattern. They were more frequent in females and younger patients and had a higher incidence of colorectal carcinomas and other tumors in the family. Chromosome 9 deletions, a hallmark of urothelial carcinomas, and the number of chromosomal alterations as detected by CGH analysis were significantly less frequent in these tumors. These data strongly suggest a distinct molecular pathway in the development of upper urinary tract tumors with mutator phenotype.

The WHO classification of renal cell carcinomas (RCC) takes into account chromosomal alterations. New cytogenetic techniques such as comparative genomic hybridization (CGH) and fluorescence in situ hybridization (FISH) offer alternative methods to the classic cytogenetic banding technique. Clear cell (classic) RCC frequently show the loss of 3p. Papillary RCC are characterized by trisomies and tetrasomies as well as loss of the Y chromosome. CGH analysis demonstrates that DNA copy increase is more common in type I papillary RCC compared to type II. Chromophobe RCC are characterized by losses in chromosomes 1, 2, 6, 10, 13, 17, and 21. Oncocytomas can be divided into cases with rearrangements in the 11q13 region and those with loss of chromosome 1 and the sex chromosomes. Translocations involving chromosome 3, such as t(3;8)(p14;q24.13) and t(2;3)(q35;q21) have been described in familial clear cell RCC. The most recent class of RCC, seen only in men, is referred to as translocation tumors. These tumors demonstrate a tubulopapillary growth pattern and have a t(X;1)(p11.2;q21.2) translocation. Although not required for most clinical diagnoses, CGH and FISH complement the standard histologic diagnosis of RCC and may provide a definitive diagnosis in a small number of challenging cases.

The Roberts-SC phocomelia syndrome is a rare autosomal recessive inherited disorder clinically manifested by tetraphocomelia, pre- and postnatal growth retardation, and craniofacial abnormalities (skull, eyes, lip, and palate), accompanied at times by centromer puffing and splitting, renal abnormalities, heart defect, clitoral or penile enlargement, and bilateral corneal opacities. Mental retardation is common in surviving patients.

Like in man, in neoplastic haematopoietic diseases of the dog genetical changes can be detected cytogenetically. In this study, some cytogenetically characterized cases are presented and discussed against the background of comparable cases reported in the literature. In two out of three patients investigated, one or two extra copies of chromosome 1 were detected. Corresponding changes have also been described in two other cases in the literature.

Primary cultures of 48 cases of prostate carcinoma were established. The expression of cytokeratin and prostate specific antigen were determined in the cultures routinely. G-banding analysis revealed some clonal numerical and structural aberrations: Trisomy 7 occurred in 4 cases, in one case in combination with a t(Y;22). Loss of the Y chromosome was found in 3 cases, in one case in combination with gain of chromosome #5. The most frequent clonal structural aberration var9(qh) occurred in 6 cases. A deletion of 6q(23) was found in two cases. None of these aberrations were found in normal tissue of the same patients. Numerical changes were demonstrated by fluorescence in situ hybridization (FISH) on native tissue, confirming the conventional cytogenetic findings.

The clinical picture and the course of the disease of seven patients with the 5q-syndrome are described. Examination of peripheral blood revealed refractory anaemia with macrocytosis, anisocytosis, poikilocytosis of erythrocytes, and platelet anisocytosis with some giant platelets. Characteristic bone marrow findings are megaloblastic dyserythropoiesis and micromegakaryocytes with hypolobulated nuclei. Cytogenetically, an interstitial deletion of the long arm of chromosome 5 is always found, associated with a haploid loss of the genes for the growth factors GM-CSF, M-CSF and IL-3. The disease is usually chronic, and only in the case of clonal evolution is there a considerable risk of leukemic transformation occurring. In the chronic phase, infusion of packed red cells as required individually has proved a reliable form of treatment. The results of chemotherapy have disappointed both in the chronic and acute phases of the disease.

We performed chromosome studies in 131 patients presenting with hypospadias, with the aim of detecting any causal connections between chromosomal abnormalities and the induction of hypospadias. Autosomal abnormalities were revealed in 6 and sex chromosomal abnormalities in 10 patients. Although a significant causal relationship between the occurrence of hypospadias and chromosomal abnormalities was seen in this study in only two cases of mixed gonadal dysgenesis (45,X/46,XY and streak gonad), the high incidence of chromosomal abnormalities observed (12.2%) seems noteworthy compared with the incidence of only 0.61% in the normal male population.

Cytogenetic findings contribute not only to a detailed classification of malignant lymphomas, but also to better prediction of prognosis. Therefore cytogenetic findings gain increasing importance in lymphoma diagnosis. Here, the characteristic chromosome abnormalities t(8;14)(q24;q32), t(2;8)(p12;q24), t(8;22)(q24;q11), t(14;18)(q32;q21), t(11;14)(q13;q32), + 12, + 3 and t(2;5)(p23;q35) and their molecular consequences are described.

Genetic factors, especially numerical chromosome anomalies, play an important role in embryonic loss. Since somatic cell analysis cannot assess the risk of errors arising de novo during germ cell maturation, we investigated, whether the male gametes from couples with habitual abortion (group HA) carry a higher rate of anomalies, than those from donors without reproductive dysfunction (group K). Chromosomes were demonstrated after fusion of sperm with zona-free golden hamster ova. Our results indicate no significant difference between the two groups for the total rates of aneuploidy (HA: 3.6%, K: 2.0%) and structural anomalies (HA: 15.3%, K: 7.0%). However, the levels of chromosome breaks and acentric fragments were significantly higher in the abortion group (5.8% and 8.1%, respectively, vs. 2.4% each in group K). The implications of this fact remain to be investigated.

This study was designed to assess the feasibility of amniocentesis and amnion cell culture for prenatal diagnosis in early weeks of gestation (less than 15 weeks). Within a period of 18 months (1/88-6/89) 135 diagnostic amniocenteses were performed between 10 and 14 weeks and amniotic fluid was obtained in all instances. In all cases but one, sufficient cell cultures and chromosomal analyses were achieved. In the follow up, one miscarriage (0.7%) occurred, in two cases transient amniotic fluid leakage ceased spontaneously. All of the aforementioned complications were related to amniocenteses in weeks 11 and 12. The course of the continued pregnancies as well as fetal outcome were without any further complications. Comparing specimens of early and regular (16-18 weeks) amniocenteses in terms of time required for cell culture and karyotyping as well as the quality of chromosomal banding no significant differences were found. In contrast to maternal serum AFP which increased continuously, amniotic AFP levels could be seen to increase to a peak at 13 weeks' gestation but afterwards gradually declined. Based on these first experiences and results of early amniocenteses the specific problems of this method are discussed. In summary, it is concluded, that early amniocentesis between 12 and 14 weeks of gestation is feasible with regard to both the technique of amniotic fluid retrieval and the technique of chromosomal analysis. Early amniocentesis, therefore, could fill up the diagnostic gap between chorionic villi sampling (CVS) between 9 and 11 weeks of gestation and "classical" amniocentesis during weeks 16-18.

In a sister and a brother with striking similarity of facial dysplasias, severe disturbance of expressive speech, and mild mental retardation a partial trisomy of the long arm of chromosome 4 was identified as cause of these anomalies. The partial trisomy 4q was due to a balanced translocation between the chromosomes 1 and 4 in the father of both children.

Congenital stationary night blindness is a rare disease with autosomal dominant, autosomal recessive, or X-linked recessive inheritance. The X-chromosomal form is frequently associated with myopia. Female carriers have no symptoms of visual impairment and therefore cannot be identified clinically. The close link recently described between the disease locus and the DXS7 locus, mapped in Xp11.3, as well as other marker loci from this chromosomal region, permits indirect genotype analysis and thus identification of the carriers; with the information thus obtained, improved genetic counseling is possible. The authors studied a large Swiss family with the X-linked trait. Segregation analysis was performed with DXS7 as well as two flanking markers, DXS255 and OTC. It was thus possible to determine the degree or probability of several female members of the family being carriers.

Many spontaneous abortions are caused by chromosome abnormalities of zygotes or embryos. We found chromosome aberrations in 15 of 59 successful cultivated tissues of miscarriages. The detecting of one trisomy 2 in these investigations is remarkable. At the same time we examined the chromosomes of couples suffering from repeated abortions. 21 of 512 tested females and 12 of 474 tested males showed abnormal chromosome sets. The results and their consequences are discussed.

In the case of characteristic chromosomal deletion of chromosome 15(q11----q13) the diagnosis of the Prader-Willi syndrome can be already confirmed in early infancy as shown in our case report. In this connection cytogenetic high-resolution techniques are indispensable. Cytogenetic and clinical problems are discussed.

In males affected by a special form of X-linked mental retardation a characteristic chromosomal abnormality can be demonstrated, - i.e. a fragile site on the long arm of the X chromosome, fra(X) (q27 or 28) (marker-X chromosome). Male carriers are physically normal, but in most cases show macroorchidism. The demonstration of the marker-X chromosome requires special cell culture conditions, above all a folic acid-deficient medium. The frequency of cells with fragile X chromosome varies interindividually, ranging from 2 to 50%. In female heterozygous carriers the number of cells with fra(X) decreases with age and cannot be demonstrated in some cases. Distribution and frequency of X-linked mental retardation with marker-X chromosome and macro-orchidism are discussed, as well as possibilities of prenatal diagnosis of this disorder.

Studies conducted by Atkin and Pickthall are likely to suggest more frequent occurrence in normal cells of enlargement of the heterochromatin region of the A1 chromosome in patients with ovarian carcinoma, and its is also claimed to be a predisposing factor, in the context of ovarian carcinoma. - The authors of the paper have tried to find out, if they could draw similar conclusions from their own patients and, therefore, applied cytogenetic tests of lymphocytes to 50 patients, including 25 who had undergone treatment for ovarian carcinoma and 25 control probands. - An assessment was made of 298 mitoses. C-bands were accurately measured and calculated in 84 mitoses of both groups. --The dimensions of A1 heterochromatin were variable in the authors' preparations, too. However, such variability in size in either group is considered still as normal variant of the well-known A1 polymorphism, and the authors were not convinced that pathognomonic relevance should be attributed to those findings. - Enlarged C-band of A chromosome was recordable only from one lymphocyte culture of one patient with ovarian carcinoma. C-banding, consequently, cannot be considered a suitable screening method for ovarian carcinoma, in the context of lymphocyte culturing.

Chromosome variants (= markers) are segments of variable length and staining properties which do not exert an apparent impact on the phenotype of the person. These variants mainly include centromeric segments on chromosomes 1, 3, 4, 9, 13-15, 21, 22 and the distal long arm of the Y chromosome. Individual markers differ by their variable length and fluorescence intensity following Q-staining. Inheritance is dominant, and fresh mutations occur very rarely indeed. Markers can be used for the following purposes: To demonstrate the take of a bone marrow transplant; to determine zygosity in like-sexed twins and paternity (both already feasible during the fetal period); to determine maternal versus paternal origin of additional chromosomes (trisomies), of de novo structurally altered chromosomes, and of haploid sets in triploidy and chimerism.

Karyotype analysis using the Tri-staining-technique (Chromomycin A3/Distamycin A/DAPI) and subsequent DAPI/AMD staining (Schweizer, 1981) was performed on the bone marrow and peripheral blood of three patients with "Burkitt-like" acute lymphatic leukaemia (FAB: L3). In two patients we found the specific translocation t(8;22). One patient displayed in addition a structural abnormality of chromosome 9, visualized with C-banding using the DA/DAPI stain, and in two patients we found specific abnormalities of chromosome 1. Several patterns of the abnormal chromosome 1 revealed an intercalated DA/DAPI positive C-band in the elongated long arm.

Cytogenetic studies on biopsies of cervix uteri (5 dysplasias, 2 carcinomas in situ and 13 invasive carcinomas) are reported in this paper in order to detect the numerical and structural chromosome changes. In dysplasias, the deviation number is mostly restricted around the diploid mode while in carcinomas the range of deviation is wider and more than one modal number could be identified. Structural aberrations of chromosome 1 were found in one case of dysplasia and in 10 cases of invasive carcinomas. A long acrocentric was observed in three carcinomas and one dysplasia, while a medium-sized metacentric in three carcinomas. Further markers : minute chromosomes (in two carcinomas) and double minute bodies (DMs, in one carcinoma). These studies and the early ones suggest that the changes of chromosome 1 may be a relative late appearance of malignant transformation. The possible role of DMs is also discussed.

Recent models for the organization of the chromosomes of eukaryotes in mitosis and interphase are discussed with respect to their condensation hierarchy. Possible functional interpretations are indicated. At present, an alternating coiling and loop formation, induced by histones and nonhistone proteins, respectively, appears to be the most probable structure. The relationship of DNA properties to chromatin structure and function is also briefly discussed.

A newborn male with multiple malformations and an extrachromosome is presented. The cytogenetic study of peripheral blood lymphocytes revealed tetrasomy 9p: 47,XY, + t(9;9)(pter----q13::p11----pter). The C-banding pattern provided evidence for maternal origin of the extrachromosome. Tetrasomy for the short arm of chromosome 9 is a very rare condition; reports about only ten further patients have been found in the literature. The phenotypic expression resembles trisomy 9p, but tetrasomy 9p has more severe additional malformations.

A cytogenetical study has been conducted in patients with impaired spermatogenesis and reduced fertility or complete sterility to investigate the frequency of chromosomal aberrations in this condition. 78 patients with azoospermia and 74 patients with a sperm count of below 20 million/ml have been studied cytogenetically and endocrinologically between 1977 and 1981. Numerical or structural chromosomal aberrations were found in 27 out of the 152 patients. In two phenotypically normal males hitherto-undescribed balanced autosomal translocations were detected.

In the study reported here the incidence and significance of translocations in antenatal diagnosis are described with reference to data of the cytogenic laboratory of Cologne University Gynecological Clinic. During the last 10 years 19 translocations were found in 4532 amnion cell cultures (0.44%), without exception in single pregnancies. In 18 cases the chromosome aberrations were balanced, i.e., the location of the genetic material was changed without loss or addition of parts of chromosomes. In one case the diagnosis of an unbalanced translocation in the form of a translocation mongolism led to termination of pregnancy. All of the other pregnancies were continued to term. Phenotypically and clinically the children were normal. The translocations were inherited in 78.9% (n = 15; 11 from the mother, 4 from the father), and de novo in 21.1% (n = 4). The results are in agreement with those of the DFG study, which identified 0.66% translocations in over 10,000 antenatal diagnoses. Of the balanced chromosome aberrations all of the newborns but one were clinically and phenotypically healthy. In cases of inherited translocations in particular, no increase in risk to the child could be determined. In cases of de novo chromosome aberrations there is a slight increase in the residual risk due to loss of minute portions of the gene. With careful technique this risk may be assumed to be very slight, so that in such cases also there is no indication for termination of pregnancy.

We report a paternity testing case in which a decisive clue was a deletion of the short arm of chromosome 13 in the child and in his putative father.

Methodological prerequisites for the culture of leukaemic blasts and the fluorescence banding of spread metaphases are represented in detail. By using an improved method the percentage of aneuploid karyotype findings increased in AML from 49% to 68% and ALL from 65% to 81% of all evaluable patients. Specific aberrations known up to the present day are discussed. They could be diagnosed in 46% of aneuploid AML-clones and in 59% of ALL-clones. The fluorescence banding according to the three-colour technique is demonstrated by three examples of "non-specific" aberrations: a) Tandem translocation of 1q and 7 q (64a, male, FAB:M5B), b) Karyotype instability with variability of chromosome numbers arising from trisomy, tetrasomy and polyploidisation of single normal as well as marker chromosomes (57a, female, FAB:M6), c) Identification of a marker chromosome as a derivative chromosome 16 (33a, female, FAB:L2, c-ALL).