Poster #069, Children's Hospital Los Angeles
Characterizing Novel Arg20Trp Mutation in MODY9 iPSCs
Mentors: Marney Granados, B.S and Senta Georgia,PhD
Diabetes is a condition that affects beta cells in the pancreas, which are responsible for insulin production, secretion, and maintaining the body’s overall blood glucose levels. MODY, or Maturity-Onset Diabetes of the Young, is a rare form of diabetes caused by a single genetic mutation that causes a disruption in normal pancreatic development. A recent Children’s Hospital Los Angeles (CHLA) patient was found to have a novel Arg20Trp point mutation in their PAX4 gene, which is associated with subtype MODY-9. PAX4 is a transcription factor responsible for repressing alpha cell differentiation during stages 5-6 of endocrine development, therefore bolstering beta cell production. Null studies have shown in the absence of PAX4, beta cell populations are reduced and less mature, followed by an increase in alpha cell production. Although this novel mutation has unknown clinical significance, computational studies suggest this mutation is likely pathogenic. Additionally, the mutation is located in the paired-domain of the protein, shown to be responsible for recognizing and binding to target sequences. Therefore, we hypothesize the novel Arg20Trp mutation will affect PAX4’s transcriptional function. We aim to understand this by characterizing newly derived “MS-29” induced pluripotent stem cells (iPSCs). We differentiated 3 clones of MS-29 iPSCs (#3,#4, #7) and H1 embryonic stem cells (ESCs) into stages 5 and 6 of beta cell differentiation and analyzed cells for stage specific markers using flow cytometry and immunocytochemistry. We expect mutant MS-29 cells to have inefficient beta cell differentiation and have less beta cell markers compared to control ESC lines.