Early White Matter Microstructure Alterations in Infants with Down Syndrome

Area of Science:

• Neuroscience
• Genetics
• Developmental Biology

Background:

• Down syndrome (trisomy 21) is the most common chromosomal disorder, leading to intellectual disability.
• Early brain development, especially white matter microstructure, is significantly impacted, yet research in infants is limited.

Purpose of the Study:

• To investigate early white matter microstructure in infants with Down syndrome.
• Utilize advanced neuroimaging techniques, including diffusion tensor imaging (DTI) and neurite orientation dispersion and density imaging (NODDI).

Main Methods:

• Prospective cohort study involving infants with and without Down syndrome.
• Scanned 49 infants with Down syndrome and 37 controls at 6 months of age using DTI and NODDI.
• Analyzed white matter microstructure in association tracts and optic tracts.

Main Results:

• Infants with Down syndrome exhibited reduced fractional anisotropy and neurite density in major association tracts, indicating compromised structural integrity and delayed myelination.
• Increased orientation dispersion index in specific tracts suggested altered neurite organization.
• Optic tracts showed a unique pattern of accelerated maturation in Down syndrome infants.

Conclusions:

• This study provides the first comprehensive characterization of white matter microstructure in infants with Down syndrome.
• Findings reveal widespread delays in white matter development, offering crucial insights into early neurodevelopmental trajectories.
• Results may inform the development of targeted early therapeutic interventions for Down syndrome.