[Cytogenetic risk categories in acute myeloid leukemia: a comparison between MRC (Medical Research Council) and SWOG (Southwest Oncology Group) models)]. / Grupos de riesgo citogenético en la leucemia mieloide aguda: comparación de los modelos adoptados por los grupos MRC (Medical Research Council, del Reino Unido) y SWOG (Southwest Oncology Group, de EE.UU.).

BACKGROUND AND OBJECTIVE: Classification of acute myeloid leukemia (AML) based on karyotype provides an important tool for therapy selection. There are two standardized criteria for the classification of patients into groups of cytogenetic risk. One of them was established by the UK Medical Research Council (MRC) and the other by the US Southwest Oncology Group (SWOG). They define three and four cytogenetic categories, respectively. The aim of this study was to define the frequency of chromosomal abnormalities and to compare the groups of cytogenetic risk in patients with AML who received intensive chemotherapy, as a guide for future investigations. PATIENTS AND METHOD: Chromosomal analysis was performed using standard techniques on bone marrow samples from 146 adult patients between January 1995 and December 2001. Kaplan-Meier and Cox's regression models were used for statistical analysis. RESULTS: Cytogenetic results were obtained in 142 patients. The incidence of a complex karyotype and del(5q) was higher in patients with secondary AML. Classification by cytogenetic risk was performed in 105 treated patients. The classification using both models was identical in 82 patients and different in 23. Results in univariate analysis were significant for EFS (p < 0.000 for MRC and p < 0.02 for SWOG). Nevertheless, only the MRC model was significant for OS (p < 0.001). In multivariate analysis, age and cytogenetics were the only variables having prognostic value. CONCLUSIONS: There was some relation between secondary AML, advanced age and adverse karyotype. Both classification models have a great prognostic value. In our experience, codification according to MRC criteria appears to be more effective to detect patients at high risk of relapse.

Chromosomal anomalies in patients with short stature.

BACKGROUND: The incidence of chromosomal anomalies in patients with short stature (SS) was studied in order to determine the value of routine karyotyping in this population. METHODS: This study was a retrospective evaluation of 972 patients (719 females and 253 males) with SS. Chromosomal analysis was performed on cultured peripheral lymphocytes. RESULTS: The incidence of chromosome aberrations in males was 2.77% (7/253) and in females 9.8% (71/719). Several groups were made according to clinical features and familial antecedents of SS. We observed different incidence rates of chromosomal anomalies among groups of patients, mainly in females. The incidence in the group without familial antecedents was 18.89%, however, in females with familial antecedents it was 4.45%. In females with isolated SS we detected karyotype anomalies in the 3.98%, while in patients with phenotypic features, amenorrhoea and SS the incidence was 77.78%. In females the most frequent anomaly was Turner syndrome, present in 55 patients (77.46%). CONCLUSION: Karyotype analysis is recommended for all girls with unexplained SS and associated abnormalities. In females with isolated SS a cost-benefit analysis must be done in each case.

SRY-positive 46,XX male with cryptorchidism as the only presenting clinical feature.

The SRY gene, located on the short arm of the Y chromosome, is responsible for differentiation of the testis from the undifferentiated gonad. We report a 4-year-old patient with male phenotype and female karyotype (46,XX) with cryptorchidism as the only presenting clinical abnormality. Fluorescent in situ hybridization analysis, using Y- and X-specific (whole chromosome painting WCP Y WCP X) DNA and SRY probes, detected a small Y chromosome fragment, including the SRY gene, transferred to the short arm of the X chromosome.