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Monozygotic Twins Discordant (monozygotic + twin_discordant)
Selected AbstractsSpecific bronchoalveolar lavage fluid T cells associate with disease in a pair of monozygotic twins discordant for sarcoidosisJOURNAL OF INTERNAL MEDICINE, Issue 6 2001J. Grunewald Abstract.,Grunewald J, Eklund A (Karolinska Hospital, Stockholm, Sweden). Specific bronchoalveolar lavage fluid T cells associate with disease in a pair of monozygotic twins discordant for sarcoidosis (Case report). J Intern Med 2001; 250: 535,539. A 49-year-old Caucasian woman had an acute onset of sarcoidosis. Bronchoscopy with bronchoalveolar lavage (BAL) showed a pronounced accumulation of BAL fluid CD4+ T cells expressing the T-cell receptor (TCR) AV2S3 gene. In line with this observation, the patient was HLA-DR17 positive, previously shown to strongly correlate with lung compartmentalized AV2S3+ T cells. At follow-up after recovery, reduced numbers of BAL fluid AV2S3+ T cells were found. Interestingly, BAL fluid of a healthy monozygotic twin sister contained normal numbers of AV2S3+ lung T cells. This report shows the T-cell repertoire of BAL fluid T cells to correlate with the disease (sarcoidosis), indicating a local and specific immune response triggered by an unknown antigen in sarcoidosis. [source] Disc degeneration and bone density in monozygotic twins discordant for insulin-dependent diabetes mellitusJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 5 2000T. Videman The effects of insulin-dependent diabetes mellitus on bone density and connective tissue degeneration have theoretical interest and practical relevance. Several experimental studies in animals have demonstrated the harmful effects of insulin deficiency on connective tissues. However, clinical studies in humans have produced somewhat contradictory results, most likely due to difficulties controlling for general degeneration and factors associated with diabetes. In nine pairs of monozygotic twins discordant for insulin-dependent diabetes mellitus, we compared femoral and lumbar bone mineral density (assessed by dualenergy x-ray absorptiometry) and spinal degeneration (assessed by magnetic resonance imaging). The bone densities were, on average, 0.1,0.3% lower (p = 0.87,0.96) in diabetic patients. However, after controlling for smoking, we found that the bone density in the femoral neck was 2.5% (0.025 g/cm2) lower in diabetic individuals than in their twins (p = 0.09). The five magnetic resonance imaging parameters used to evaluate discdegeneration did not differ between diabetic patients and their twins. In conclusion, our results provide no evidence that insulin-dependent diabetes mellitus has any major effect on bone density or disc degeneration. [source] Prenatal diagnosis of female monozygotic twins discordant for Turner syndrome: implications for prenatal genetic counsellingPRENATAL DIAGNOSIS, Issue 8 2002B. Gilbert Abstract We describe a set of monozygotic (MZ) female twins, one of whom presented with a typical Turner syndrome (TS) phenotype and the other a normal female phenotype. Prenatal fetal ultrasonographic examination showed a monochorial diamniotic pregnancy with a hygroma colli and growth delay in Twin A and no anomalies in Twin B. Karyotypic analysis performed on fetal blood samples demonstrated a 46,XX/45,X (23/2) mosaicism in Twin A and a normal 46,XX chromosome constitution in Twin B. At birth, Twin A presented with a typical TS and Twin B had a normal female phenotype. Postnatal cytogenetic investigation of blood lymphocytes showed the same 46,XX/45,X mosaicism in both twins: 46,XX/45,X (40/7) in Twin A and 46,XX/45,X (40/5) in Twin B. Further investigations at the age of 10,months showed in Twin A a 46,XX/45,X (98/2) mosaicism in lymphocytes and 100% of 45,X (50 analysed cells) in fibroblasts, and in Twin B a normal 46,XX (100 analysed cells) chromosome constitution in lymphocytes but a mild 46,XX/45,X (78/2) mosaicism in fibroblasts. Monozygosity was confirmed by molecular analysis. To our knowledge, this is the first report of prenatal diagnosis of MZ female twins discordant for TS. Review of reported sets of MZ female twins (eight cases) or triplets (one case) discordant for TS shows, as in the present case, that the phenotype correlates better with the chromosomal distribution of mosaicism in fibroblasts than in lymphocytes. In the blood of MZ twins chimerism may modify the initial allocation of the mosaicism. These results suggest that, in cases of prenatal diagnosis of MZ female twins discordant for TS, the phenotype of each twin would be better predicted from karyotype analysis of cells from amniotic fluid than from fetal blood. Copyright © 2002 John Wiley & Sons, Ltd. [source] | ||||||||||