Early Brain Development in Twins
The purpose of this study is to study the role of genes and environment in early brain development using a twin approach. The investigators will use magnetic resonance imaging (MRI) to study brain structure and it's relationship to cognitive development. Specifically, the investigators will study cortical gray and white matter volumes, volumes of subcortical structures and cerebellum, as well as diffusion properties in major white matter tracts using DTI tractography.
Twin Brain Development
|Study Design:||Observational Model: Cohort
Time Perspective: Prospective
|Official Title:||Early Brain Development in Twins|
- Brain Gray Matter Volume [ Time Frame: Change in heritability from birth to age 6 years ] [ Designated as safety issue: No ]Will assess gray matter volume with MRI and use stuctural equation modeling to determine relative contributions of genes and environment to variation of gray matter volumes.
- Brain white matter tract integrity [ Time Frame: Change in heritability from birth to age 6 years ] [ Designated as safety issue: No ]Will asseess white matter tract developemnt and integrity using diffusion tensor imaging and will determine realtive contributions of genes and environment ot this using twin methodology.
- Mullen composite Score [ Time Frame: 1,2,4,6 years ] [ Designated as safety issue: No ]Will assess genetic and environmental contributions to early cogntive development using a twin methodology
Biospecimen Retention: Samples With DNA
buccal swabs; MRIs, ultrasounds
|Study Start Date:||April 2004|
|Estimated Study Completion Date:||March 2014|
|Estimated Primary Completion Date:||March 2014 (Final data collection date for primary outcome measure)|
Twin studies have been critical in determining the contributions of genetic and environmental factors to normal brain structure and for understanding abnormalities of brain development that underlie neurodevelopmental and neuropsychiatric disorders. In adults and older children, twin studies indicate that genes play a significant role in the variability of global brain volumes, including total brain, total gray and total white matter volumes. Other than this current study, there have been no studies of twin brain development in early childhood, the period of brain development implicated in the pathogenesis of many psychiatric disorders. In the first funding cycle of this grant, the investigators used prenatal ultrasound and neonatal MRI to study discordance of early brain development, and to determine genetic and environmental contributions to neonatal brain structure. The investigators have and have developed a unique and valuable cohort of twins, having recruited and scanned over 100 twin pairs. The investigators found that discordance of prenatal brain size in MZ twins is similar to that in DZ twins, but that by 1 month after birth, discordance of overall brain volume in MZ twins is already less than in DZ twins. Contrary to our original hypothesis, statistical modeling of neonatal MRI brain volumes in our twin cohort indicates that global tissue volumes are highly heritable, similar to that observed in older children and adults. Therefore, it appears that genetic programs act very early in postnatal brain development to determine global tissue volumes. Interestingly, preliminary longitudinal mapping of correlations in gray matter density indicate correlations decrease in the first year of life, perhaps as the result of rapid brain growth in the first years of life. The investigators also found that while global white matter volumes are highly heritable, diffusion tensor properties of specific white matter tracts are not. In the next funding cycle, the investigators propose to continue enlarging this unique cohort and to follow them through age 6 years with structural MRI, diffusion tensor imaging (DTI), and developmental assessments to determine how genetic and environmental factors contribute to brain development in the first years of life.
|Contact: John H Gilmore, MDfirstname.lastname@example.org|
|United States, North Carolina|
|UNC Department of Psychiatry||Recruiting|
|Chapel Hill, North Carolina, United States, 27599|
|Contact: John Gilmore, MD 919-966-6971 email@example.com|
|Principal Investigator: John H Gilmore, MD|
|Principal Investigator:||John H Gilmore, MD||University of North Carolina, Chapel Hill|