Combined factor V Leiden and prothrombin genotyping in patients presenting with thromboembolic episodes.

BACKGROUND: Several genetic defects are associated with increased risk of venous thrombosis. The factor V Leiden (FVL) and prothrombin G20210A mutations are the most frequent causes of inherited thrombophilia. OBJECTIVES: To evaluate combined genotyping for these 2 mutations in patients presenting with thromboembolic episodes and to correlate genotypic findings with clinical characteristics. RESULTS: Blood specimens were collected from 401 patients presenting with thromboembolic disease between January 1998 and September 1998, and genotyping for both FVL and prothrombin mutations was performed. Thirty-two patients (8%) were heterozygous for FVL, 4 (1%) were homozygous for FVL, and 20 (5%) were heterozygous for the prothrombin mutation. Two cases (0.5%) were identified with combined FVL and prothrombin mutations. The most common clinical presentation was lower-extremity deep vein thrombosis with or without pulmonary embolism. Arterial events were rare. The thromboembolic episodes were often precipitated by additional risk factors. Recurrent disease was found in 73.9% of FVL carriers and 52.9% of prothrombin mutation carriers; 52% of the patients with FVL and 50% of prothrombin mutation carriers had a first thrombotic episode before age 45 years. The 2 cases with combined genetic defects demonstrate amplified thrombotic risk. In the first case this was effected in thrombosis at a young age, and recurrence of thrombotic events even in the absence of precipitating factors. A complex interplay between genetic and additional risk factors was seen in the second case. CONCLUSIONS: Identification of both FVL and prothrombin mutations is important in the overall assessment and management of patients with thrombophilia. Detection of these mutations can identify patients at high risk and help evaluate the interaction of genetic and acquired risk factors.

Myelodysplastic syndrome at a large tertiary care community hospital: analysis according to the international prognostic scoring system.

The outcome of patients diagnosed myelodysplastic syndromes (MDS) between 1990 and 1997 from William Beaumont Hospital (WBH) was analyzed according to the International Prognostic Scoring System (IPSS) risk categorization. A retrospective study of 195 MDS patients wa s performed. Seventy-nine patients with MDS, in whom a karyotype was obtained and with an adequate follow-up were included in the final analysis. Cases of proliferative CMML (WBC > 12x10(9)/l) were excluded from the study. The overall median survival was 3.1 years, and median survival stratified by IPSS was 3.4, 4.1 and 0.5 years for the INT-1, INT-2 and high risk group and not yet reached for the low risk group. The overall survival by IPSS subcategorization were 6.88, 5.29, 5.30 and 2.12 years for the low, INT-1, INT-2, and high risk groups respectively. Cytogenetics were significant in predicting the overall survival. The IPSS score stratified patients into risk categories for development of AML. The risk of development into AML was 8, 8, 33 and 54% for the low, INT-1, INT-2 and high risk groups, respectively. We conclude that IPSS score can be useful in predicting survival and AML evolution in some MDS patients.

Differential expression of the MT-1E gene in estrogen-receptor-positive and -negative human breast cancer cell lines.

The goal of this study was to determine which of the 10 functional metallothionein (MT) genes are expressed in four human breast cancer cell lines and whether expression varies among the cell lines. Using reverse transcription polymerase chain reaction (RT-PCR) technology, it was shown that there was no expression of mRNA for the MT-1A, MT-1B, MT-1F, MT-1G, MT-1H, MT-3, and MT-4 genes in any of the four cell lines. All four cell lines were shown to express mRNA for the MT-2A and MT-1X genes. The expression level of mRNA for the MT-2A gene demonstrated modest differences among the cell lines, whereas expression of the MT-1X gene was consistent. In contrast, mRNA for the MT-1E gene was expressed in only two of the four cell lines and expression correlated to the estrogen receptor status of the cell lines. The two estrogen-receptor-positive cell lines showed no mRNA expression for the MT-1E gene. In the two estrogen-receptor-negative cell lines, mRNA expression for the MT-1E gene was elevated with expression levels similar to the housekeeping gene, glyceraldehyde-3-phosphate dehydrogenase. The cellular content of MT protein was also shown to be elevated in the estrogen-receptor-negative cell lines that express MT-1E mRNA. These results suggest a possible relationship between estrogen receptor status and MT-1E gene expression in human breast cancer.