Prenatal diagnosis of isochromosome 21p and isochromosome 21q in a fetus with Down syndrome.

The aim of this study was to present the first case with Down syndrome in conjunction with de novo isochromosomes of both short and long arm of the chromosome 21. Cytogenetics, molecular cytogenetics and molecular genetic analysis were performed on chorionic villus sampling at 12 weeks of gestation of a 42-years-old pregnant woman. According to cytogenetics, molecular cytogenetics and molecular genetic analysis the karyotype was designated as: 47,XY,i(21) (qter --> q10::q10 --> qter),+i(21) (pter --> p10::p10 --> 10pter).ish i(21)(qter --> q10::q10 --> qter)(CEP13/21+,WCP21+),+i(21) (pter --> p10::p10 --> pter)(CEP13/21+,WCP21+). Quantitative Fluorescent Polymerase Chain Reaction (QF-PCR) analysis revealed that isochromosome 21q was maternal in origin. After the detailed genetic counseling, the family decided termination of the pregnancy. This is the first report of co-existence of an isochromosome 21p and an isochromosome 21q in a case with Down syndrome. Our case shows the importance of the molecular cytogenetics and molecular genetic analysis in cases with isochromosomes of the acrocentric chromosomes and supernumerary marker chromosomes regarding to highlight of the formation mechanisms of co-existence of these two rearrangements.

RLIP76 Gene Variants are not Associated with Drug Response in Turkish Epilepsy Patients.

Approximately 30% of epileptic patients remain untreated, in spite of trials with maximum tolerable doses of more than one drug. The RalA binding protein 1 (RALBP1/RLIP76), a multifunctional, anti-apoptot-ic, multidrug transporter protein, has been proposed as being responsible for the drug resistance mechanism in epilepsy. We have investigated polymorphic differences in the coding regions and exonintron boundaries of the RLIP76 gene, between 146 refractory and 155 non refractory epileptic patients in Turkey, using denaturing high performance liquid chromatography (HPLC) and sequencing analysis techniques. We have detected the following sequence variants: c.160-4G>A, c.187C>G, c.1562-38G>A, c.1670+107G>A, c.1670+93G>A, c.1670+96G>A, c.1670+100C>T, c.1670+130C>T, c.1670+131G>C, c.1670+140 G>C, and found no statistically significant correlation between allele frequencies and drug response status. We conclude that sequence variants of this gene are not involved in drug resistance in epilepsy.

AIDIT and IMPACT: building research collaborations in targeted prostate cancer screening.

AIDIT (Advancing International Co-operation and Developing Infrastructure for Targeted Screening of Prostate Cancer in Men with Genetic Predisposition) is a project funded by the Sixth Framework Programme of the European Community which is endeavouring to facilitate co-operation between European countries in the field of cancer research. The project also aims to raise awareness of familial prostate cancer among health professionals and the public within the associated candidate countries (ACCs) and new member states of the European Union (EU). AIDIT will focus on linking clinical and research teams in the ACCs and new member states with the IMPACT Consortium (Identification of Men with a genetic predisposition to ProstAte Cancer: Targeted screening in BRCA1/2 mutation carriers and controls), an international team investigating screening and diagnosis for men with a genetic risk of prostate cancer predisposition genes BRCA1 or BRCA2). Cancer research has been targeted as a high priority for the European Community; however, research is most successful when centralised and well coordinated, avoiding the duplication and fragmentation associated with smaller, isolated studies. AIDIT will consolidate the current IMPACT consortium and allow research partners from across the world to benefit from shared knowledge and experience. To date, the AIDIT team has established a website to facilitate communication between project collaborators (www.impact-study.co.uk), has been represented at several international meetings and has facilitated a conference for the IMPACT study to bring together international research teams, clinicians and policy makers.

A case with de novo interstitial deletion of chromosome 7q21.1-q22.

A case with de novo interstitial deletion of chromosome 7q21.1-q22: A patient with multiple congenital anomalies was found to have a de novo proximal interstitial deletion of chromosome 7q21.1-q22. The patient was 10.5 years of age, and manifestations include growth retardation (below 3rd percentile), mental retardation, mild microcephaly, hypersensitivity to noise, mild spasticity, short palpebral fissures, alternant exotropia, compensated hypermetropic astigmatism, hypotelorism, hypoplastic labia majora and minora, clinodactyly of fingers 4 and 5. Molecular studies revealed that the deletion had a paternal origin, while chromosomes of both parents cytogenetically were shown to be normal. Molecular, and fluorescence in situ hybridization (FISH) analyses confirmed no deletion at the Williams-Beuren Syndrome region. Some of the heterogeneous clinical findings were consistent with previously reported cases of same chromosomal breakpoints.

Molecular analysis of beta-thalassemia and sickle cell anemia in Antalya.

We have studied 918 chromosomes for mutations leading to beta-thalassemia and sickle cell anemia, which are the two most frequently found monogenic disorders in Antalya, Turkey. Three hundred and seventy-seven postnatal and 82 prenatal cases were studied between 2000 and May 2003 in our center using reverse dot blot hybridization (RDBH) with 22 probes specific for Mediterranean populations. In this study, IVSI-110 (G-->A) appeared to be the most common mutation with an occurrence rate of 44.4% among the 16 different mutations found to be associated with beta-thalassemia. Heterozygosity for IVSI-110 was the most prevalent combination, whereas 34 of our 377 postnatal cases showed homozygosity for this mutation, a genotype leading to beta-thalassemia major. The total percentage of postnatal patients clinically diagnosed as beta-thalassemia major was 18.6%, whereas 5% of the cases were diagnosed clinically as beta-thalassemia intermedia. One new Hb variant, Hb Antalya, and one new mutation, Cod 3 (+T) were found. HbS accounted for 10.3% of all mutations; homozygosity was found in 1.9% of all cases. Of the 82 cases analysed prenatally for beta-globin gene mutations and by cytogenetic techniques for possible chromosomal abnormalities, 21 fetuses were found to be affected with beta-globin gene mutations. One of these fetuses was also found to have a 45,X karyotype, and 1 had a 46,XY/47,XY,+22 karyotype. Quite a high rate of consanguineous marriages in Antalya (35.17%) renders mutation screening, genetic counseling, and educational programs held by our Thalassemia Unit essential. This study was the first to be performed specifically in our region where hemoglobinopathies are most frequent as a consequence of migrations of racially and culturally distinct groups to the area in the distant past.