Inheritance of a Chromosome 3 and 21 Translocation in the Fetuses, with One also Having Trisomy 21, in Three Pregnancies in One Family.

The majority of chromosome rearrangements are balanced reciprocal and Robertsonian translocations. It is now known that such abnormalities cause no phenotypic effect on the carrier but lead to increased risk of producing unbalanced gametes. Here, we report the inheritance of a translocation between chromosomes 3 and 21 in a family with one of two fetuses with Down Syndrome carrying the same translocation and the other also carrying the same translocation without the additional chromosome 21. Chromosomal analysis from fetal amniotic fluid and peripheral blood lymphocytes from the family were performed at the Çukurova University Hospital at Adana, Turkey. We assessed a family in which the translocation between chromosomes 3 and 21 segregates: one of the three progenies carried the 47,XX,+21,t(3;21)(q21;q22) karyotype and presented with Down Syndrome; another of the three progenies carried the 46,XX,t(3;21) (q21;q22) karyotype and the third had the 46,XY karyotype. Their mother is phenotypically normal. Apparently this rearrangement occurred due to an unbalanced chromosome segregation of the mother [t(3;21)(q21;q22)mat]. This family will enable us to explain the behavior of segregation patterns and the mechanism for each type of translocation from carrier to carrier and their effects on reproduction and numerical aberrations. These findings can be used in clinical genetics and may be used as an effective tool for reproductive guidance and genetic counseling.

Rapid detection of fetal aneuploidies by quantitative fluorescent-polymerase chain reaction for prenatal diagnosis in the Turkish population.

Prenatal diagnosis is testing for diseases or conditions in a fetus or embryo before it is born. It employs a variety of techniques to determine the health and condition of an unborn fetus. The main goal of this process is to perform prenatal diagnosis at the earliest possible stage of gestation. In this regard, quantitative fluorescent-polymerase chain reaction (QF-PCR), a novel technique that is fast and reliable, was employed to detect aneuploidies (13, 18, 21, X and Y) without the need of the time-consuming culturing process. The QF-PCR method can detect five different chromosome aneuploidies with 98.6% accuracy. In this study, 1874 amniotic fluid samples of pregnant subjects, who were referred to the Department of Medical Biology and Genetics, Adana, Turkey (molecular biology section), were analyzed with the QF-PCR technique by employing 27 short tandem repeat (STR) markers to detect chromosomes 13, 18, 21, X and Y aneuploidies. We detected 31 subjects (1.7%) with aneuploidies or euploidies out of the 1874 subjects. The average age of the pregnant subjects was 32 (range: 14-49). Abnormal karyotypes detected were as follows: 47,XX,+21 (19.4%, 6/31), 47,XY,+21 (48.4%, 15/31), 48,XXX,+21 (3.2%, 1/31), 69,XXX (3.2%, 1/31), 47,XY,+13 (3.2%, 1/31), 47,XXY (9.6%, 3/31), 47,XXX (9.6%, 3/31) and 45,X (3.2%, 1/31). Moreover, some STR markers were found to be more specific to the Turkish population. In conclusion, QF-PCR can be regarded as an alternative method of conventional cytogenetic analysis as it is a rapid and reliable method; however, in most cases it is required to be supported or validated with conventional cytogenetic karyotyping and some STR markers employed for QF-PCR can be more informative for a given population.

Association between Obsessive Compulsive Disorder and Tumor Necrosis Factor-α Gene -308 (G>A) and -850 (C>T) Polymorphisms in Turkish Children.

Obsessive compulsive disorder (OCD) is a neurobiological disease characterized with obsessions and compulsions. Obsessive compulsive disorder occurs with an autoimmune mechanism after Group A ß hemolytic streptococcus (GABHS) infection. Tumor necrosis factor (TNF) is an important cytokine, as well as having an important role in the apoptosis mechanism of autoimmune diseases. It is expressed by the TNF-α gene. The aim of this study was to examine the relationship between the TNF-α gene promoter region -308 (G>A) and -850 (C>T) polymorphisms and OCD. In this study, ages of the OCD patients and the control group ranged between 4 and 12 years. We studied two patient groups, one included childhood onset OCD patients (n = 49) and the control group was composed of healthy children (n = 58). Patients were diagnosed according to the Diagnostic and Statistical Manual of Mental Disorder (DSM-IV) criteria and with Kiddie Schedule for Affective Disorders and Schizophrenia-Present and Lifetime (KSAD-S-PL) version. For identifying the polymorphisms, polymerase chain reaction (PCR), restriction fragment length polymorphism (RFLP) and polyacrylamide gel electrophoresis (PAGE) methods were used. For the -308 polymorphism, 45 of 49 OCD patients' results were completed, and for the -850 polymorphism, 47 of 49 OCD patients' results were completed. According to our statistical results, there is a positive relationship between OCD and the -308 polymorphism (p <0.001) but no association between OCD and the -850 polymorphism (p = 0.053). There is no positive relationship between antistreptolysin O (ASO) titers and the -308 polymorphism (p = 0.953) but there is an important significance between the -850 polymorphism and ASO (p = 0.010). There is no positive relationship between gender of patients and OCD (p = 0.180) and no positive association between ASO and gender (p = 0.467). According to our results, we hypothesize that we can propose the mutant AA genotype for the -308 polymorphism, and that the mutant CT genotype for the -850 polymorphism may be used as molecular indicators for OCD.