A hypothesis is proposed here that RET rearrangements in papillary thyroid cancers are related to the disease duration and tumor progression. The most common RET rearrangements are RET/PTC1 and RET/PTC3. RET/PTC1 is more prevalent in classic papillary thyroid carcinoma (PTC), its diffuse sclerosing variant, and papillary microcarcinoma; while RET/PTC3 is frequently found in less differentiated solid PTC. RET/PTC3 is associated with larger tumor size and multifocality in sporadic pediatric PTC. The RET rearrangements; especially RET/PTC3, which is frequently detected among Chernobyl thyroid cancers is developed after exposure to radiation at an early age, is proposed to be a potential trigger of malignancy. There are many late-stage tumors among the first-wave Chernobyl PTCs that tend to be larger and less differentiated than those detected later. The high proportion of late-stage cases shortly after the accident is explained by the neglected cases in the screening process and also by the fact that some non-exposed patients were registered as radiation-exposed. The screening was productive because of the reservoir of undiagnosed cases in the population: registered incidence of thyroid cancer (TC) among children and adolescents prior to the Chernobyl disaster was low in the Soviet Union; compared to other developed countries. In conclusion, RET rearrangements, especially RET/PTC3, were correlated with the tumor progression. If the hypothesis defended here is correct, a low prevalence of RET/PTC3 among sporadic TC is circumstantial evidence of efficient cancer diagnosis and early detection.

One of the major causes of spontaneous abortion before the fourth month of pregnancy is CHROMOSOMAL abnormalities. We report an unusual case of a familial balanced CHROMOSOMAL translocation in a consanguineous couple who experienced 4 spontaneous abortions. CHROMOSOMAL studies were performed on the basis of Gbanding technique at high resolution and revealed 46, XX, t (16, 6) (p12, q26) and 46, XY, t (16, 6) (p12, q26) in both partners, which induced such pregnancy complications.CHROMOSOMAL balanced translocation is one of the most common causes of recurrent spontaneous abortions (RSA). In such cases prenatal diagnosis (PND) during the 16th week of gestation is strongly recommended.

Objective: CHROMOSOMAL aberrations are common causes of multiple anomaly syndromes. Recurrent CHROMOSOMAL aberrations have been identified by conventional cytogenetic methods used widely as one of the most important clinical diagnostic techniques.Materials and Methods: In this retrospective study, the incidences of CHROMOSOMAL aberrations were evaluated in a six year period from 2005 to 2011 in Pardis Clinical and Genetics Laboratory on patients referred to from Mashhad and other cities in Khorasan province. Karyotyping was performed on 3728 patients suspected of having CHROMOSOMAL abnormalities.Results: The frequencies of the different types of CHROMOSOMAL abnormalities were determined, and the relative frequencies were calculated in each group. Among these patients, 83.3% had normal karyotypes with no aberrations. The overall incidences of CHROMOSOMAL abnormalities were 16.7% including sex and autosomal CHROMOSOMAL anomalies. Of those, 75.1% showed autosomal CHROMOSOMAL aberrations. Down syndrome (DS) was the most prevalent autosomal aberration in the patients (77.1%). Pericentric inversion of chromosome 9 was seen in 5% of patients. This inversion was prevalent in patients with recurrent spontaneous abortion (RSA). Sex CHROMOSOMAL aberrations were observed in 24.9% of abnormal patients of which 61% had Turner’s syndrome and 33.5% had Klinefelter’s syndrome.Conclusion: According to the current study, the pattern of CHROMOSOMAL aberrations in North East of Iran demonstrates the importance of cytogenetic evaluation in patients who show clinical abnormalities. These findings provide a reason for preparing a local cytogenetic data bank to enhance genetic counseling of families who require this service.

Propranolol (PL), a non-selective beta-blocker, is a cardiovascular drug widely used to treat hypertension. The present study was concerned with assessing the cytogenetic effects of this drug on Chinese hamster ovary (CHO) cell line. MTT assay was then carried out to determine the cytotoxicity index (IC50) of the drug. The IC50 value of PL was 0.43±0.02 mM. To investigate the clastogenic effects of the drug, chromatid and chromosome breaks and polyploidy in metaphases were analyzed. CHO cells were exposed to different concentrations of the drug (0.1, 0.2, 0.3, 0.4 mM) for 24 hours. Considering that PL has liver metabolism, experiments were carried out in the presence and absence of the metabolic activation system (S9 mix). Mitomycin-C and sodium arsenite were used as positive controls. It was observed that in cells treated with different PL concentrations as 0.1, 0.2 and 0.3 mM, the frequency of chromatid and chromosome breaks as well as polyploidy increased when compared with untreated CHO cells. The addition of S9 mix significantly decreased the chromatid breaks, chromosome breaks and polyploidy compared to the treatment of PL alone. It is concluded that, PL causes chromatid and chromosome aberrations in CHO cell line and the metabolic activation system (S9 mix), playing an important role in drug cytotoxicity reduction.

CHROMOSOMAL microdeletions are usually accompanied with medical and developmental concerns. Although same microdeletions obviously are not symptomatic during childhood, some other deletions are related to clinical manifestations in neonates such as growth and neurodevelopmental delay, feeding difficulties, hypotonia, andmotor developmental DEFECTS (1). Cardiovascular anomalies have been revealed to affect up to half of all neonates born with a 10q26 microdeletion (2). The described case was a female neonate (11 month, 15 days) with the birth weight of 2400 g that was born through cesarean section from a 25-years old healthy mother (G3P2Ab1L1). The patient was the second child of the family with no abnormal condition in first child...

Introduction: The aim of this study which was done for the first time in Iran, was the assessment of CHROMOSOMAL abnormalities in patients with oral cancer.Materials & Methods: For clinical, epidemilogic and probable CHROMOSOMAL abnormalities evaluation, 45 patients with oral cancer were selected from patients referred to oral disease department of Mashhad dental school and Emam Reza, Ghaem and amid hospitals.We performed clinical examination and biopsy for confirming diagnosis of oral cancer. After pathology confirmation, two blood samples (containing EDTA and heparin) were prepared from patients who had not received any treatments (radio therapy, chemical therapy or antibiotic therapy) during the previous two weeks. Heparinized blood samples were transported to genetic laboratory for cell culture.Results: Cell culture of 30 patients was done successfully and the other 15 which failed, were excluded from the study. In Karyotype examination, no CHROMOSOMAL abnormalities were detected in these patients. Conclusion: Minor CHROMOSOMAL disorders can not he studied through current available procedures in Iran and FISH system which makes further studies available, had not been put into practice in Iran so far. Molecular genetic study and gene isolation can help in detecting gene effect on oral cancer.  

Germination vigour is one of the most important factors for plant stablishing under drought stress. In order to detect of quantitative trait loci related to drought tolerance in germination stage a genetic map was provided by 74 SSR marker and 192 individuals of F2:4 derived from cross between Tarom mahalli´Khazar population. The hundred seeds of 20 families were used for recording of germination rate, radical length and plumule length. Seventy four SSR markers grouped in 12 linkage groups. Thirteen QTLs were detected for traits. Three QTLs were mapped on chromosome 1 that increased drought tolerance in germination stage in rice. Out of these QTLs, qGR-1a distinguished as major effect and explained 26.27% of the total variation. Correlations between traits and overlapping QTLs in RM466-RM259 interval provided a good region for gene pyramiding and marker assisted programs.

The most significant complication of pregnancy is recurrent miscarriage. Numerous factors have been described as associations with recurrent wastage such as: uterine abnormalities, immunological factors, endocrinologic imbalance and CHROMOSOMAL DEFECTS. Cytogenetic evaluation of couples with recurrent pregnancy losses is performed on the basis of G-banding technique only after other possible etiologic factors have been excluded. The purpose of this study was to determine the frequency of balanced translocation in 153 couples who were introduced to the medical genetic laboratory by gynecologists. The prevalence of balanced CHROMOSOMAL translocation was 9.8% among which 3.3% appeared with Robertsonian translocation and the remaining (6.5%) was evident with different type of balanced CHROMOSOMAL rearrangement. The yield of positive results for balanced CHROMOSOMAL translocation carrier was lower than that expected. With regard to the low incidence of balanced translocation in normal population and high cost and time-consumption of CHROMOSOMAL analysis cytogenetic investigation should be suggested only in couples with recurrent spontaneous abortions when clinical data fail to clarify the cause