PT  - JOURNAL ARTICLE
AU  - Lancaster, Jack L.
AU  - Cody, Jannine D.
AU  - Andrews, Trevor
AU  - Hardies, L. Jean
AU  - Hale, Daniel E.
AU  - Fox, Peter T.
TI  - Myelination in Children with Partial Deletions of Chromosome 18q
DP  - 2005 Mar 01
TA  - American Journal of Neuroradiology
PG  - 447--454
VI  - 26
IP  - 3
4099  - http://www.ajnr.org/content/26/3/447.short
4100  - http://www.ajnr.org/content/26/3/447.full
SO  - Am. J. Neuroradiol.2005 Mar 01; 26
AB  - BACKGROUND AND PURPOSE: We compared myelin levels in white matter (WM) in typically developing children with those of children with partial deletions of chromosome 18q (18q−).METHODS: Conventional spin-echo MR imaging at 1.9T was used to acquire T1-, T2-, and proton density-weighted images of the brain. From these images, a three-pool model was used to estimate the fraction of water in myelin, myelinated axon, and mixed water compartments (or pools) in six WM regions. A model curve was fit to the pool fractions to model the trend of myelin development by age in each region. Water-pool fractions in children with 18q− aged 5 months to 13 years were compared with those of age-matched, typically developing children.RESULTS: In children with 18q−, the model predicted later onset of myelination (P < .02), lower myelination rates (P < .001), and smaller equilibrium myelin pool fractions (P < .001). Significant differences were seen between the two groups for all three water pool fractions (P < .001). The mixed pool fraction was larger in children with 18q−. Although the myelin pool fraction was significantly smaller, the myelinated axon pool fraction was only slightly smaller, leading to a significantly smaller estimate of myelin per myelinated axon in children with 18q− (P < .001).CONCLUSION: Myelination modeling in 18q− children indicated delayed onset, a lower rate of myelination, and equilibrium myelin levels less than 50% those of age-matched, typically developing children.