OHSU

Child Health Pilot Project Abstract - Maslen, Cheryl, PhD

Maslen, Cheryl, PhD, Professor, Dept. of Cardiology, OHSU

“Genetic modifiers of cognitive function in Down syndrome”

The goal of this pilot project is to gather preliminary data to support a large-scale study of genetic factors that influence variability in cognitive abilities of persons with Down syndrome.

Down syndrome (DS) is a commonly occurring condition resulting from trisomy 21. One of the principle features of DS is decreased cognitive function. Nearly 1 in 700 children is born with DS, making it one of the most frequent causes of mental retardation. Individuals with DS require considerable resources for special education, long-term supervisory care, and economic support because of their limited intellectual capabilities. The presentation of trisomy 21 is highly variable between individuals. In particular, levels of cognitive function vary across a large range. Some individuals with DS have nearly normal cognitive function, while others are severely limited. This suggests that the initial genetic challenge represented by trisomy 21 is further modified by genetic background variation. The goal of this project is to gather preliminary data to support a large-scale study of genetic factors that influence cognitive variability in DS. Successful genetic analyses require well-defined phenotypes, but little is known about the specifics of cognitive deficiency in DS. It is clear that standard IQ measures do not reflect true cognitive ability in DS. The aim of this pilot study is to carefully define cognitive phenotypes in DS using a series of validated tests that measure cognitive function of different areas of the brain. These phenotypes will become the basis for identifying well-characterized cohorts for genetic analyses designed to discover genetic variation contributing to cognitive deficits. Once identified, these genetic sources of variability become targets for improving the lives of individuals with DS by optimizing functions at every opportunity.