Chromosome Analysis Of Peripheral Lymphocytes Research Articles

The Genotoxic Effect of Interventional Cardiac Radiologic Procedures on Human Chromosomes

In recent years, an important part of the ionizing radiation (IR) that human have been exposed for diagnostic purposes are interventional radiologic procedures. The X-rays and contrast media are used in angiography. The patients and staff members are exposed to X-ray during these procedures. While it is known that X-rays cause DNA damage and carcinogenesis, the effect of the contrast agent is still unknown. The aim of this study was to investigate the effect of X-rays and contrast agent on chromosomes of human patients. Peripheral blood samples were taken from 50 patients (30 males, 20 females, ages between 38-75 years). Chromosome analysis of peripheral lymphocytes in 50 patients were performed at 3 different periods; before the interventional radiologic procedure, 24 hours and 1-3 months after the procedure. Also, chromosome analysis was performed on 17 staff members working during interventional radiological procedures to investigate the effect of X-rays. Standard cytogenetic analysis techniques were used for this study. The frequency of chromosomal aberrations (CAs) was significantly higher in patients 24 hours after the interventional radiologic procedures than pretreatment (p=0,000). At the same time, CAs after 24 hours compared with those taken 1-3 months later, shown that the CAs were significantly reduced after 1-3 months (p=0,000). We also found that the frequency of CAs was also statistically higher in patients exposed to high radiation doses (p=0,042). Compared with the control group (n=30), CAs were found significantly higher in workers exposed to radiation. Our findings have shown that X-rays and contrast agents that used in interventional radiological cause chromosomal damage. For this reason, the dose of radiation to be given to the patient must be carefully selected. Due to the potentially high genetic damage of patients with coronary artery disease (CAD), the type and amount of medication to be given and the frequency of radiological diagnostic procedures to be performed should be meticulously adjusted.

Clinical and radiological findings in Pallister–Killian syndrome

Pallister–Killian syndrome (PKS) is a potentially lethal disorder with facial dysmorphism, pigmentary skin anomalies, developmental delay and major visceral anomalies, such as diaphragmatic hernia, anorectal malformation, and congenital heart disease. PKS is causally associated with mosaic tetrasomy of chromosome 12p. A routine chromosome analysis in peripheral lymphocytes usually fails to detect the mosaic state. A prompt diagnosis rests on clinical awareness and a subsequent chromosome or molecular analysis in fibroblasts, buccal mucosal cells, or bone marrow cells. We report here on three infants with PKS. One infant had aortic dilatation, a previously unreported association in PKS. More importantly, all infants showed a recognizable, though mild, pattern of skeletal changes mainly affecting axial bones, including delayed ossification of the vertebral bodies and pubic bones, flared anterior ribs, and broad metaphyses of the long bones, particularly of the femora. These skeletal changes should be considered as a useful diagnostic sign in PKS. Awareness of the axial skeletal alterations can be helpful in prompting clinicians to search for mosaic tetrasomy 12p and perform chromosomal analysis in appropriate tissue types.

Lethal Pallister-Killian syndrome and Fryns syndrome: diagnostic considerations

Clinical similarities between Pallister-Killian and Fryns syndrome have been previously noted. A newborn with diaphragmatic hernia, diffuse corneal opacities, dysmorphic fades, and hypoplastic nails was believed to have Fryns syndrome. Chromosome analysis of peripheral lymphocytes showed 46, XY in 20 cells counted (525 band level). Despite maximal support, the baby remained unresponsive to therapy. Given the poor prognosis, it was agreed that respiratory support be discontinued. Autopsy confirmed a large left diaphragmatic defect/pulmonary hypoplasia, bilateral ureteral dilation, and intraventricular hemorrhage. Mild shortening of the upper limbs and cleft of the soft palate were also noted. Testicular tissue chromosome analysis showed isochromosome 12p in all 20 cells examined. There appears to be a subset of patients with Pallister-Killian who present in utero or neonatally with lethal manifestations. The most common cause of death in these individuals has been a large diaphragmatic hernia with resultant pulmonary hypoplasia. Although reports vary, the frequency of diaphragmatic hemia in lethal Pallister-Killian syndrome may be as high as 50%. We suspect that Pallister-Killian, lethal type, is underdiagnosed. Most routine cultured lymphocyte chromosome analyses will not demonstrate isochromosome 12p, leaving Fryns syndrome as the most likely diagnosis. Our case further substantiates the need for solid tissue chromosome examination in individuals with diaphragmatic hemia and other congenital anomalies.

Chromosome analysis of peripheral lymphocytes from persons exposed to radioactive fallout in Norway from the Chernobyl accident

Chromosome analysis of peripheral lymphocytes from two Norwegian populations (44 reindeer herding South samis from Røros and Snåsa, 12 sheep farmers from Valdres) exposed to fallout from the Chernobyl accident were made. The doses from caesium through the years 1987–1991 were calculated based on whole-body measurement of 134Cs and 137Cs giving a total cumulative mean internal dose of 5.54 mSv for the total group of 56 persons. Chromosome aberrations were within the normal range when compared with historical controls with the exception of dicentrics (0.3% per cell, which is a 10-fold increase) and rings (0.07% per cell). A dose-dependent increase in dicentrics and rings based on caesium exposure was not observed.

Identification of the triploid genome by the C-banding method.

We report on cytogenetic studies of a malformed fetus, whose clinical symptoms indicated the diagnosis of triploidy. This was confirmed by chromosome analysis of peripheral lymphocytes of cord blood. Using the C-banding method it was possible to identify the origin of the extra haploid set: marker chromosomes indicate, that nonreduction of the first meiotic division in the father's spermiogenesis most probably leads to triploidy. However, in our case fertilization of the zygote by two sperms cannot be excluded.