RT Journal Article
SR Electronic
T1 MR-Revealed Myelination in the Cerebral Corticospinal Tract as a Marker for Pelizaeus-Merzbacher's Disease with Proteolipid Protein Gene Duplication
JF American Journal of Neuroradiology
JO Am. J. Neuroradiol.
FD American Society of Neuroradiology
SP 1822
OP 1828
VO 20
IS 10
A1 Jun-ichi Takanashi
A1 Katsuo Sugita
A1 Yuzo Tanabe
A1 Kasumi Nagasawa
A1 Ken Inoue
A1 Hitoshi Osaka
A1 Yoichi Kohno
YR 1999
UL http://www.ajnr.org/content/20/10/1822.abstract
AB BACKGROUND AND PURPOSE: Pelizaeus-Merzbacher's disease (PMD) is caused by mutations in the proteolipid protein (PLP) gene. Recent studies have shown that an increased PLP dosage, resulting from total duplication of the PLP gene, invariably causes the classic form of PMD. The purpose of this study was to compare the MR findings of PMD attributable to PLP duplication with those of PMD arising from a missense mutation.METHODS: Seven patients with PMD, three with a PLP missense mutation in either exon 2 or 5 (patients 1–3), and four with PLP duplication (patient 4 having larger PLP duplication than patients 5–7) were clinically classified as having either the classic or connatal form of PMD. Cerebral MR images were obtained to analyze the presence of myelination and T1 and T2 shortening in the deep gray matter. Multiple MR studies were performed in six of the seven patients to analyze longitudinal changes.RESULTS: Four patients (patients 1–4) were classified as having connatal PMD, whereas the other three (patients 5–7) were classified as having classic PMD. Myelination in the cerebral corticospinal tract, optic radiation, and corpus callosum was observed in three cases of classic PMD with PLP duplication. In patient 4, myelination extended to the internal capsule, corona radiata, and centrum semiovale over a 3-year period. No myelination was observed in three PMD cases with a PLP point mutation. T2 shortening in the deep gray matter was recognized in all patients with PMD.CONCLUSION: The presence of myelination in the cerebral corticospinal tract with diffuse white matter hypomyelination on MR images could be a marker for PMD with PLP duplication. It is suggested that progression of myelination may be present in connatal PMD with large PLP duplication.