Genetics analysis with down syndrome and histopathological examination of buccal epithelial cells / Análisis genético y examen histopatológico de las células epiteliales bucales en pacientes con síndrome de down

Down syndrome is primarily caused by trisomy of chromosome 21. We reviewed cytogenetic studies performed on 1048 patients who were referred to the Cytogenetics Unit at Dicle University Hospital, Diyarbakir, Southeast Turkey, between 2000 and 2009. The cases were grouped according to the reason of referral for cytogenetic analysis. The highest frequencies of abnormal karyotypes were found among cases that were referred due to suspicion of Down syndrome (84.8 percent). For histologic examination to persons with Down syndrome and normal, buccal mucosa smear was prepared by rubbing. Down syndrome are disabled and control groups were compared statistically buccal epithelial cells and nuclei (p<0.05). Periphery of the nucleus in some patients with Down's syndrome, while the bud structures in the form of micronuclei was observed in the karyolytic cells.

El síndrome de Down es causado principalmente por la trisomía del cromosoma 21. Se revisaron los estudios citogenéticos realizados en 1.048 pacientes que fueron remitidos a la Unidad de Citogenética del Dicle University Hospital, Diyarbakir, sudeste de Turquía, entre los años 2000 y 2009. Los casos se agruparon de acuerdo a la razón de referencia para el análisis citogenético. Las frecuencias más altas de cariotipos anormales se encontraron ent los casos que fueron remitidos por sospecha de síndrome de Down (84,8 por ciento). Para el estudio histológico de las personas con y sin síndrome de Down, se realizó el frotis de mucosa oral por hisopado. Los grupos con síndrome de Down y de control (sin síndrome) se compararon estadísticamente en relación a las células epiteliales orales y los núcleos (p <0,05). Se observaron núcleos periféricos en algunos pacientes con síndrome de Down, mientras que estructuras de tipo brotes en la forma de micronúcleos se observaron en las células cariolíticas.

Chromosome heteromorphisms are more frequent in couples with recurrent abortions.

Chromosomal heteromorphism is considered a variant of a normal karyotype, but it is more frequent in couples with repeated miscarriages. We investigated chromosomal heteromorphism in couples with repeated miscarriages in comparison with a control group. A total of 455 couples who applied to our genetic diagnosis laboratory in Diyarbakir, Turkey, were evaluated for chromosome heteromorphisms; 221 of these couples (the study group) had recurrent abortions and 234 of them (the control group) had no history of abortions and had at least one living child. The patient group of couples with recurrent abortions were found to have a significantly higher rate of chromosome heteromorphism (8.4%) in comparison with the control group (4.9%). When the patients were evaluated according to gender, males had a significantly higher rate of chromosome heteromorphism (11.3%) than females (5.4%). We conclude that since couples with recurrent abortion and males have higher rate of chromosome heteromorphism, cases of heteromorphism should not be disregarded in the etiological investigation of recurrent abortions. Further research should be done to investigate the phenotypic effects of chromosome heteromorphism.

Evaluation of clinical and cytogenetic findings on 1,068 second-trimester amniocenteses in Southeast Turkey.

OBJECTIVE: To investigate the indications of amniocentesis for the detection of chromosomal abnormalities among a sample of patients in Southeast Turkey. MATERIAL AND METHODS: Between 2004 and 2007, 1,068 second-trimester amniocentesis tests were performed in the Medical Biology and Genetics Department Laboratory at Dicle University. Amniotic fluids were cultured by using long-term tissue culture for prenatal diagnosis with cytogenetic analysis. The clinical and cytogenetic findings on 1,068 second-trimester amniocenteses were analyzed. The indications, the proportions of karyotypes according to indications and complications were summarized. RESULTS: Among the 1,068 amniocentesis cases, the maternal age between 35 and 39 years was the most common age group (34.5%). Of the clinical indications abnormal maternal serum screening results were the most common indication for amniocentesis (37.6%). Of 52 cases (4.9%) with detected chromosomal aberrations, 39 were numeric (27 trisomies, 10 sex chromosome aberrations and two triploidies) and 13 were structural (2 reciprocal translocations, 2 Robertsonian translocations and 6 inversions). The highest detection rate of chromosome aberrations was in cases undergoing amniocentesis for abnormal maternal serum screening combined with abnormal ultrasound (US) findings (8.0%). CONCLUSION: This study suggests that complementary measures, such as routine antenatal US and maternal serum screening, should be added to increase the efficiency of genetic amniocentesis. Therefore, the study could be used for the establishment of a database for genetic counseling.

Cytogenetic analysis of 4216 patients referred for suspected chromosomal abnormalities in Southeast Turkey.

We reviewed cytogenetic studies performed on 4216 patients who were referred to the Cytogenetics Unit at Dicle University Hospital, Diyarbair, Southeast Turkey, between 2000 and 2009. The cases were grouped according to the reason of referral for cytogenetic analysis. The frequencies of the different types of numerical and structural abnormalities were determined, and the relative frequency of cases with abnormal karyotypes was calculated in each group. The most common reason for requesting cytogenetic testing was referral for Down syndrome and for repeated abortions. The highest frequencies of abnormal karyotypes were found among cases that were referred due to suspicion of Down syndrome (84.8%). Among the chromosomal abnormalities, sexual chromosomal abnormalities were found in 239 cases (17.6%), and Klinefelter syndrome was the most frequent sex chromosomal abnormality. Autosomal abnormalities were found in 1119 cases (82.4%), and Down syndrome was the most frequent autosomal chromosomal abnormality. In conclusion, the high rate of chromosomal abnormalities (32.2%) found in this population demonstrates the importance of cytogenetic evaluation in patients who show clinical abnormalities. This is the first report on cytogenetic testing in the southeast region of Turkey. This type of study provides a basis for determining the risks of recurrence and for deciding on clinical treatment and genetic counseling.