Biology Project Abstract
ASSOCIATION OF SCHIZOPHRENIA WITH A BALANCED TRANSLOCATION OF CHROMOSOMES 6 AND 11
Presenters:
Maciej Mroczek, Illinois Mathematics and Science Academy, 1500 West Sullivan Road, Aurora, IL, 60506; mmroczek@imsa.edu
Sridhar Narla, Illinois Mathematics and Science Academy, 1500 West Sullivan Road, Aurora, IL, 60506; stnarla@imsa.edu
Mentors:
Dr. Pablo V. Gejman, Evanston Northwestern Healthcare,1001 University Place, Evanston, IL, 60201; 224-364-7550; pgejman@northwestern.edu
Dr. Alan Sanders, Evanston Northwestern Healthcare, 1001 University Place, Evanston, IL, 60201; 224-364-7560; asanders@northwestern.edu
Abstract:
Our main mentorship project has focused on examination for the possibility of a balanced translocation of chromosomes 6 and 11 in families with members suffering from schizophrenia. Holland and Gosden (1990) suggested a possible relationship between the translocation and psychotic illness in a three-generation English family where both were present. A few years later, Jeffries et al. (2003) molecularly defined the translocation breakpoint, thus enabling the development of an assay to examine for the presence of the translocation in schizophrenia families collected by Dr. Gejman and others over the years, most of which have British Isles ancestry and which have shown previous evidence for linkage of schizophrenia to the region of chromosome 6 where the breakpoint occurs. Therefore, we are examining DNA collected from individuals in families with schizophrenia for evidence of this balanced translocation of chromosomes 6 and 11. We are using two sets of PCR (polymerase chain reaction) primers for our tests: F6, R6, F11, and R11 (F=forward, R=reverse, and the numbers correspond to the chromosome). For example, pairing F6 and R6 should amplify a DNA segment residing on a normal chromosome 6, and pairing F6 and R11 should amplify a DNA segment residing on a translocation chromosome containing part of chromosome 6 and part of chromosome 11. Thus far, we have examined 192 DNA samples using the F6 and R11 primer, including a positive control DNA (i.e., DNA from a member with the translocation from the original family in which the translocation was discovered). After electrophoresis six samples each displayed a specific band (indicating a DNA segment of a particular size) when the PCR products were separated based on size via agarose gel electrophoresis with ethidium bromide staining of the DNA; two of these samples corresponded to the positive control DNA. Since the other samples displayed a band we hypothesize that the subjects corresponding to these samples have the translocation in their DNA. Our next steps are (1) to complete the initial screen of the collection, (2) to re-check the entire families of positive subjects from the initial screen, and (3) if replicated thusly, the next step would be sequencing to further identify and confirm the presence of the chromosomes 6 and 11 translocation breakpoint in these subjects. We are also considering examining for the presence of the translocation in a control sample, i.e., one without individuals with schizophrenia.