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Magnetic resonance imaging (MRI) and MRI relaxometry were used to investigate disturbed brain myelination in 18q- syndrome, a disorder characterized by mental retardation, dysmorphic features, and growth failure. T1-weighted and dual spin-echo T2-weighted MR images were obtained, and T1 and T2 parametric image maps were created for 20 patients and 12(More)
Individuals with a constitutional chromosome abnormality consisting of a deletion of a portion of the long arm of chromosome 18 (18q-) have a high incidence ( approximately 95%) of dysmyelination. Neuroradiologic findings in affected children report a smaller corpus callosum, but this finding has not been quantified. This is in part due to the large(More)
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(More)
Chromosome rearrangements are caused by many mutational mechanisms; of these, recurrent rearrangements can be particularly informative for teasing apart DNA sequence-specific factors. Some recurrent translocations are mediated by homologous recombination between large blocks of segmental duplications on different chromosomes. Here we describe a recurrent(More)
Although constitutional chromosome abnormalities have been recognized since the 1960s, clinical characterization and development of treatment options have been hampered by their obvious genetic complexity and relative rarity. Additionally, deletions of 18q are particularly heterogeneous, with no two people having the same breakpoints. We identified 16(More)
We examined 36 participants at least 4 years old with hemizygous distal deletions of the long arm of Chromosome 18 (18q-) for histories of mood disorders and to characterize these disorders clinically. Since each participant had a different region of 18q hemizygosity, our goal was also to identify their common region of hemizygosity associated with mood(More)
Most individuals with constitutional deletions of chromosome 18q have developmental delays, dysmyelination of the brain and growth failure due to growth hormone deficiency. We monitored the effects of growth hormone treatment by evaluating 23 individuals for changes in growth, performance intelligence quotient (pIQ) and quantitative brain MRI changes. Over(More)
Inverted duplications are a common type of copy number variation (CNV) in germline and somatic genomes. Large duplications that include many genes can lead to both neurodevelopmental phenotypes in children and gene amplifications in tumors. There are several models for inverted duplication formation, most of which include a dicentric chromosome intermediate(More)
We report on a mother and child with a paracentric inversion of the long arm of chromosome 18: 46,XX,inv(18)(q21.1q23). The child had findings in common with those seen in 18q- syndrome including: microcephaly, epicanthal folds, midface hypoplasia, and abnormally modeled ears, dermatoglyphic whorls on fingertips, clubfeet, hearing loss, and developmental(More)
Chromosome 18 abnormalities are associated with a range of physical abnormalities such as short stature and hearing impairments. Psychiatric manifestations have also been observed. This study focuses on the presentations of psychiatric syndromes as they relate to specific chromosomal abnormalities of chromosome 18. Twenty-five subjects (13 with an 18q(More)