Constitutional and acquired trisomy 8.

Trisomy 8 is seen in a range of disorders both constitutional and acquired. The full constitutional condition presents with physical stigmata, skeletal abnormalities and a mild to moderately retarded IQ. Trisomy 8 is frequently seen as a mosaic in the blood or in the skin or both. Trisomy 8 as an acquired condition is found in haematological disorders, notably in myelodysplasia (MDS) and acute myeloid leukaemia (AML), and is restricted to the malignant cells. These arise in the bone marrow and may also be found in the peripheral blood. Reported in the issue (Zollino et al. (1995) Leukemia Res. 19(10), 733) is a case of a patient with constitutional trisomy 8 mosaicism who developed myelodysplasia with trisomy 8 in 95-100% of bone marrow cells. Here we consider the implications of this case to the diagnosis of both malignant and constitutional conditions.

Molecular studies of the fragile X syndrome.

We have studied families segregating for the fragile X syndrome for the presence of amplification of the CGG repeat sequence adjacent to the HpaII Tiny Fragment (HTF) island in the FMR-1 gene. We demonstrate that 138/143 fragile X positive, mentally retarded males show a characteristic smear of fragments corresponding to somatic variation in the amplification of the CGG sequence. In 7/8 normal transmitting males (NTM's), we show that there is a small amplification of sequence but no evidence for somatic variation. Defined mutated fragments in the size range found in NTM's are seen in daughters of NTM's. The daughters of these female carriers show either a defined fragment in the NTM size range, a defined larger fragment or a heterogeneous pattern of fragments. In the latter 2 cases the clinical phenotype of the females cannot easily be predicted, presumably because of variable X inactivation. In some families, the observed DNA genotype does not correlate with the phenotype; in others we demonstrate the occurrence of individuals with a mosaic DNA genotype. The implications of these data for diagnosis of the disease are discussed.

Complete and partial XY sex reversal associated with terminal deletion of 10q: report of 2 cases and literature review.

We describe 2 karyotypically male infants with terminal deletion of 10q and mental retardation, multiple phenotypic anomalies and abnormal genitalia. One [karyotype 46,XY, del(10)(q26.1)] had female external genitalia; the other [karyotype 46,XY,-10,+der(10)t (10;16)(q26.2;q21)] had an intersex phenotype. Of 8 males previously reported with terminal 10q deletion as the major or only cytogenetic abnormality, 2 had an intersex phenotype, and the others all had combinations of cryptorchidism, micropenis, and hypospadias. Terminal 10q deletions appear to be strongly associated with abnormal male genital development, and should be specifically searched for in the cytogenetic workup of such cases.

Polycythaemia rubra vera and hairy cell leukaemia in the same patient: studies on the spleen.

The first association of polycythaemia rubra vera (PRV) and hairy cell leukaemia (HCL) is reported. The secretion by spleen cells in short term culture of IfGlambda to the exclusion kappa demonstrated that despite aberrant surface marker studies the HCL was a monoclonal tumour of B cells. Chromosomal studies on splenic cells were not able to demonstrate the common clonal origin of the two tumours.

Solid tissue culture for cytogenetic analysis: a collaborative survey for the Association of Clinical Cytogeneticists.

AIMS: To survey the diagnostic service provided by UK laboratories for the culture of solid tissue samples (excluding tumours) and in particular to examine the variation in culture success rates and the problems of maternal cell overgrowth. METHODS: Twenty seven laboratories took part in a collaborative survey during 1992. Each laboratory submitted data on up to a maximum of 60 consecutive specimens (n = 1361) over a six month period. RESULTS: Skin specimens, the largest category received (n = 520), were the most problematic (51% success rate). Culture success rates were significantly lower (43%) when skin specimens (n = 140) were transported dry to the laboratory. Success rates for skin specimens also varied, depending on the origin of the specimen, from 18% for intra-uterine deaths (IUD) (n = 94) to 85% for neonatal deaths (n = 33) and 83% for live patients (n = 54). Culture of selected extra-fetal tissues from IUD, stillbirths and following elective termination of pregnancy (TOP) gave comparable success rates to those achieved for skin samples from neonatal deaths and live births. Skewed sex ratios, female > male, were identified for products of conception (POC) (n = 298) and placental biopsy specimens (n = 97). CONCLUSIONS: By appropriate selection, transport and processing of tissues, and in particular by avoiding relying solely on skin samples from IUD, stillbirths and TOP, an increase in culture success rates for solid tissue samples submitted for cytogenetic analysis could be achieved. The high risk of maternal cell contamination from POC and placental biopsy specimens was also identified in this survey.

Chromosome abnormalities involving band 13q14 in hematologic malignancies.

Fifteen patients with hematologic disorders showed abnormalities involving chromosome band 13q14. Nine patients had an interstitial deletion of this band, similar to that reported in some retinoblastoma tumors and as a constitutional abnormality in a small proportion of cases of familial retinoblastoma. In five patients, band 13q14 was involved in translocations and in one case there was a deletion of one chromosome #13 and a translocation involving the homologous #13. The diagnosis in the majority of our patients (11 of 15) was chronic lymphocytic leukemia. In these patients the abnormalities were detected in cultures stimulated with 4-phorbol 12-myristate 13-acetate (PMA). It is possible that the utilization of this agent is a fundamental requirement for the reliable demonstration of abnormalities involving 13q14 in patients with B-cell malignancies. The incidence of abnormalities involving 13q14 and their significance in the development of neoplasias, other than retino-blastoma, is discussed.

Trisomy 15 associated with loss of the Y chromosome in bone marrow: a possible new aging effect.

Trisomy 15 as a single autosomal abnormality is a rare finding in hematological disorders and has not as yet been associated with any specific disease type. We report 20 cases of trisomy 15 observed in the bone marrow of patients referred for a suspected hematological malignancy. Most patients were elderly, and a marked male predominance was evident. Aneuploidy for the Y chromosome was observed in addition to +15 in 11 out of 15 male patients. A myelodysplastic disorder (MDS) was confirmed in six cases, and acute myeloid leukemia (AML) in one. There was no evidence of malignant hematological diseases in the remaining 13 patients. We propose that there may be an association between loss of the Y chromosome and trisomy 15 and that trisomy 15, like missing Y, may not always be a marker of malignancy, but may reflect an underlying age effect. The possibility that its presence may herald the development of a malignant condition cannot, however, be excluded.

Cytogenetic Findings and Survival in B-cell Chronic Lymphocytic Leukemia. Second IWCCLL Compilation of Data on 662 Patients.

Chromosome analysis on CLL-cells from 649 patients revealed clonal changes in 311 cases (48%). The most common abnormalities were trisomy 12 (n = 112), and structural changes on the long arm of chromosome 13 (n = 62), most of them interstitial deletions or translocations involving 13q14, the site of the retinoblastoma gene. Complex karyotypes were associated with poor prognosis, although karyotypic changes rarely develop during the course of the disease. Among patients with single chromosomal abnormalities those with trisomy 12 had a poor survival, whereas those with structural changes on chromosome 13 had as good a prognosis as patients with a normal karyotype.

Predictability of VO2 max from submaximal cycle ergometer and bench stepping tests.

The predictability of the maximal oxygen uptake (VO2 max) was studied using progressive and steady state protocols for cycle ergometry and bench stepping. The subjects were 12 healthy men, 23-58 years old. Prediction of VO2 max was made by extrapolation of the heart rate and O2 uptake at several sub-maximal work-loads using the least squares regression technique. The four sub-maximal procedures underestimated the measured VO2 max by between 0.13-0.55 l.min-1. The differences between the measured and predicted values were statistically significant for the tests involving the steady state protocol. The correlation coefficients between the predicted VO2 max for each of the submaximal tests, and the measured VO2 max, were significant at the .05 level. The results indicate that for a group of male subjects VO2 max can be predicted using the progressive protocol on either the cycle ergometer or stepping bench. Individual predictions are liable to considerable error.

The behaviour of fragile X and other aberrations during recovery from low folate conditions.

Whole blood from two mentally retarded fra-X brothers was grown in low folate medium where fra-X expression was enhanced. Bromodeoxyuridine was added to mitigate the low folate conditions and metaphases were sampled sequentially, and stained for replication banding, through one cell cycle of recovery. The replication bands allowed detailed analysis of the cell cycle and the allocation of individual cells to precise sub-phases. Various classes of fra-X and all other types of chromosomal aberrations were scored in these classified cells. The fra-X does not conform in morphology to any of the known simple chromatid intrachange types, which were often present within the same cells, but the subsequent fall in frequency once bromodeoxyuridine was added closely paralleled that of the conventional aberrations. Normal folate level frequencies of fra-X are restored by the time early S-phase cells (sub-phase SkI) reach metaphase. When sub-phased cells are rearranged in true chronological sequence, there is a suggestion of a sudden fall in frequency between SkII-III (about 70% of the transit of S). This suggests that the critical point for low folate enhancement occurs in this region of the S-phase. This is somewhat earlier than the band-appearance distribution curve for Xq27 which lies within sub-phase SkIV.

Chromosomal abnormalities in B-CLL.

Amongst 141 patients with B-CLL, 53% had an abnormal karyotype. Treatment free survival was shorter in those with karyotypic abnormalities, and especially in those with multiple abnormalities. Multiple abnormalities tended to be associated with progressive disease. Trisomy 12 alone carried no worse a prognosis than a normal karyotype. 49% of patients with stage AO disease had an abnormal karyotype.

A new parental cell line for human x human hybridoma production.

The potential of a new HAT-sensitive human lymphoblastoid cell line TK6 TG(r).P1. as a fusion partner was assessed, by comparison with the established human parental cell line UC729.6. Both of these cell lines were fused with the peripheral blood mononuclear cells of a patient with B-chronic lymphocytic leukaemia. The hybridomas generated in these fusion experiments were analysed by the fluorescence activated cell sorter and karyotyping. An anti-idiotype ELISA assay detected the presence of the patient's characteristic idiotype bearing immunoglobulin in the supernatant of a number of the hybridoma cell lines generated in both fusions.

Interstitial deletion of band 3q25.

Interstitial deletions of the long arm of chromosome 3 are rare. We report a man with an interstitial deletion involving band 3q25. To our knowledge, this is the first patient to be described with this cytogenetic abnormality.

Chemical models and radiation damage.

E.s.r. spectroscopy has been used in conjunction with an aqueous flow system to investigate both the metal-catalysed decomposition of hydrogen peroxide to OH. and the subsequent reactions of this radical with a variety of biomolecules. Particular emphasis is placed on the effects of pH and ligand on the FeII-H2O2 reaction and on the sites of attack by OH. in its reaction with pyranose and furanose sugars, sugar phosphates, nucleosides and nucleotides. Attention is focused on subsequent reactions (for example, of radicals formed by attack in the ribofuranose moiety of adenosine) which may be involved in radiation damage.

Karyotypic evolution in B-cell chronic lymphocytic leukaemia.

Sequential cytogenetic studies were performed on a minimum of two and a maximum of nine occasions (mean 3.6) on the peripheral blood leucocytes of 112 patients with B-CLL. On initial cytogenetic analysis, 58 had a normal karyotype and 64 had a clonal abnormality. Karyotypic evolution occurred in 18 patients (16%). There was no significant difference in the incidence of disease progression between patients with a stable karyotype and those who underwent karyotypic evolution. In only one patient was there a clear association between disease progression, a change in cell morphology and karyotypic evolution.

Neurofibromatosis and childhood leukaemia/lymphoma: a population-based UKCCSG study.

There is a well-known raised risk of leukaemia in children with neurofibromatosis type 1 (NF-1). We carried out the first detailed population-based study of leukaemia and non-Hodgkin lymphoma (NHL) associated with NF-1 in order to estimate the risk and elucidate the relationship between these conditions. Over the 17 year study period there were five cases of chronic myelomonocytic leukaemia (CMML) in patients with NF-1 (relative risk 221; 95% CI 71-514), 12 cases of acute lymphoblastic leukaemia (ALL) (relative risk 5.4; 95% CI 2.8-9.4) and five cases of NHL (relative risk 10.0; 95% CI 3.3-23.4). Marrow cytogenetics could be reviewed for seven patients. Specific abnormalities found were monosomy 21 in a child with CMML and 7p+, 17p- in a child with ALL. No abnormalities were reported of 17q, which includes the NF1 gene. CMML occurred predominantly in boys, who also had a family history of NF-1. ALL and NHL were more often found in children with no previous family history.

Interstitial deletion of distal 13q associated with Hirschsprung's disease.

Three cases of interstitial deletion of chromosome 13 involving the common segment 13q22.1----q32.1 are reported. In addition to the recognised clinical features of this deletion, two had Hirschsprung's disease.