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The Project 

Down syndrome is caused by an extra copy of human chromosome 21 and is one of the most widely recognized genetic conditions. Individuals with DS often have differences in the development of the face and skull that can affect feeding, breathing, dental growth, speech, and social interactions. However, the biological mechanisms that cause these craniofacial differences remain poorly understood.

 

​One gene present in three copies in Down Syndrome is DYRK1A. DYRK1A produces a kinase that regulates cell division, cell behavior, and development. Increasing evidence suggests that excess DYRK1A contributes to the craniofacial features associated with DS. Understanding how elevated DYRK1A disrupts normal craniofacial development could therefore reveal an important cause of these differences.​Previous research strongly suggests that excess DYRK1A contributes to the facial differences seen in Down syndrome. People with extra copies of the DYRK1A gene often have craniofacial differences similar to those associated with Down syndrome. Mouse studies also show that increased Dyrk1a disrupts the growth and behavior of cells that form the face and skull, while restoring normal Dyrk1a levels improves craniofacial development. A small human study further suggested that reducing DYRK1A activity early in life may improve some facial measurements in children with Down syndrome.

 

Our own studies in Xenopus embryos have shown that Dyrk1a is essential for normal facial development, providing additional evidence that changes in its activity can alter craniofacial formation. Much of our work is performed in the frog Xenopus laevis, a widely used model for studying development. Model organisms allow researchers to investigate biological processes that cannot be easily examined directly in humans. During early development, the genes, signals, and cellular processes that shape the embryo are remarkably similar across vertebrates, making discoveries in Xenopus highly relevant to human development. Xenopus embryos develop rapidly outside the mother, are produced in large numbers, and can be observed and manipulated in real time. Their large, accessible embryos also support detailed imaging, molecular analysis, and efficient testing of genes and potential treatments. These strengths make Xenopus laevis a powerful system for determining how excess DYRK1A alters development in Down syndrome.