Biomedical subjects

O Verlinsky

Publications and source records attributed to O Verlinsky.

24 records · Page 2Linked to original sources

PubMed1996

Prenatal paternity testing with deoxyribonucleic acid techniques.

OBJECTIVES: Our purpose was to determine the feasibility and optimal techniques for prenatal paternity testing. STUDY DESIGN: Since January 1989 we have offered prenatal paternity testing by deoxyribonucleic acid testing. We analyzed the ability to complete the testing and the time required to complete the testing and developed polymerase chain reaction-based tests to speed test results. RESULTS: Before April 1990 only five of nine cases could be completed. Since that time 28 consecutive cases were successfully completed before delivery. Introduction of polymerase chain reaction-based testing has allowed us to perform testing on uncultured chorionic villi and to derive results within 3 weeks. CONCLUSION: Analysis of uncultured chorionic villi allows prenatal paternity testing to be completed within the first trimester of pregnancy. Prenatal paternity testing can also be performed on cultured amniocytes and chorionic villi.

Abortion, Therapeutic↗

PubMed1995

Homeobox gene expression in human oocytes and preembryos.

Homeobox gene expression in human preimplantation development has not been established. We used reverse transcriptase-polymerase chain reaction (RT-PCR) with intron spanning primer sets to investigate the presence of mRNA of homeobox genes in human oocytes and preembryos. RT-PCR products obtained from normal and unfertilized oocytes, from cleaving normal and triploid embryos, and from morulae and blastocysts were cloned, sequenced, and analyzed for the presence of homeobox sequences. The presence of mRNA of homeoboxes HoxA4 and HoxA7 was demonstrated; HoxA4 was present in normal and unfertilized oocytes and also in a 4-cell embryo. HoxA7 was present in normal oocytes and cleaving triploid embryos.

Amino Acid Sequence↗

PubMed1994

Nonisotopic identification of two point mutations in the CYP21 gene responsible for nonclassic 21-hydroxylase deficiency.

A simple nonradioactive method was developed for identification of the Pro-30-Leu and Val-281-Leu mutant alleles in the CYP21B gene. Not only does this approach improve mutation analysis for patients with the late onset form of 21-hydroxylase deficiency, but it also decreases problems with interference by the CYP21A pseudogene sequence.

Adrenal Hyperplasia, Congenital↗

PubMed1994

Review: borders, patterns, and distinctive families of homeodomains.

PURPOSE: Homeotic proteins function as transcription factors in early embryogenesis of many organisms. To date, hundreds of distinctive homeoproteins have been identified, including 84 human homeodomains. However further progress in understanding functional relationships between particular homeoproteins and other embryonic regulators requires a comprehensive structural classification of these proteins. RESULTS: The most probable borders and conservative amino acid positions inside the homeodomain region have been established using a statistical analysis of variabilities of amino acid occurrences at various positions outside and inside the domain. A new format for a homeodomain sequence presentation and regular amino acid patterns which are strongly representative of distinctive homeodomain groups are proposed. Using the established patterns, 33 families of closely related homeodomains have been distinguished and classified. The total list of 297 homeodomain amino acid sequences is presented in the Appendix. CONCLUSION: The structural classification of homeodomains has been proposed. It can be useful for both the identification (or prediction) of new homeotic genes/proteins and the recognition of possible PCR-induced sequence errors. This systematics will also have an impact on understanding functional relationships among homeotic proteins and other genetic regulators of developmental processes.

Amino Acid Sequence↗

PubMedDate not supplied

Polar body-based preimplantation diagnosis for X-linked disorders.

Preimplantation diagnosis for X-linked disorders has been performed predominantly by gender determination, which, however, leads to the discarding of 50% unaffected male embryos. In an attempt to identify X-linked mutation-free embryos for transfer, the present authors introduced preimplantation genetic diagnosis (PGD), using a sequential first and second polar body analysis, as an alternative to gender determination. This method was offered to eight couples at risk for having children with X-linked disorders, including haemophilia B, fragile-X syndrome (FMR1), myotubular myotonic dystrophy (MTMD), ornithine transcarbamylase (OTC) deficiency and X-linked hydrocephalus. The first and second polar bodies were removed following maturation and fertilization of oocytes in a standard IVF protocol and analysed using a multiplex nested polymerase chain reaction (PCR), involving testing for mutations simultaneously with linked markers. Overall, 13 PGD cycles were performed, resulting in the detection of 25 embryos with the predicted mutation-free maternal contribution; these embryos were transferred back to the patients in all cycles, yielding four clinical pregnancies. Four children were born following these pregnancies, including three unaffected and one with misdiagnosis as a result of allele dropout (ADO), which was predictable in the case of FMR1. Presented results demonstrate the clinical usefulness of the specific polar body testing for X-linked disorders as an alternative to PGD by gender determination.

Female↗

PubMedDate not supplied

Preimplantation diagnosis of single disorders.

Preimplantation diagnosis of inherited and chromosomal diseases provides an option for couples at risk for conceiving genetically abnormal fetus to avoid a birth of an affected child without the need for a prenatal diagnosis and selective abortion of affected fetus (1-3). In some countries this might be the only way to the prevention of genetic disease, as abortion is not acceptable procedure. Even in those countries where prenatal diagnosis is practiced for many years, there is also concern that existing genetic programs based on prenatal screening will lead to increasing number of abortions. On the other hand, the possibilities for genotyping oocytes and cleaving embryos open a new prospect for genetic diagnosis before pregnancy, making genetic programs more ethically acceptable in any social setting. This will make preimplantation diagnosis the method of choice in the community based programs for prevention of genetic disease in the future, as well as a useful addition to assisted reproduction technologies, at least for IVF patients of advanced maternal age.

Female↗