Pelizaeus-Merzbacher Disease: A Valine to Phenylalanine Point Mutation in a Putative Extracellular Loop of Myelin Proteolipid
In the central nervous system, myelin proteolipid protein isoforms (PLP and DM20) play an essential structural role in myelination. It has been shown in several species that myelination is impaired by molecular defects resulting from single base mutations in the PLP gene. We have used DNA amplificat...
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Published in | Proceedings of the National Academy of Sciences - PNAS Vol. 88; no. 17; pp. 7562 - 7566 |
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Main Authors | , , , , , , , |
Format | Journal Article |
Language | English |
Published |
Washington, DC
National Academy of Sciences of the United States of America
01.09.1991
National Acad Sciences |
Subjects | |
Online Access | Get full text |
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Summary: | In the central nervous system, myelin proteolipid protein isoforms (PLP and DM20) play an essential structural role in myelination. It has been shown in several species that myelination is impaired by molecular defects resulting from single base mutations in the PLP gene. We have used DNA amplification by polymerase chain reaction to study the PLP gene coding regions from 17 patients in 15 unrelated families with similar Pelizaeus-Merzbacher phenotype. In one case amplification of peripheral nerve PLP/DM20 cDNAs revealed that a silent T → C transition was unrelated to the disease. In one family a nonsilent mutation was identified that leads to a phenylalanine substitution for valine-218 in PLP/DM20 proteins. We investigated the inheritance of the mutant allele in 19 subjects of this four-generation family and found a strict cosegregation of the Phe218substitution with transmission and expression of the disease. The effect of the Val218→ Phe mutation is discussed in the frame of a recently suggested topological model of PLP/DM20, according to which Val218is part of an extracellular loop that connects the last two of four membrane-spanning α-helices. |
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Bibliography: | ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 ObjectType-Case Study-2 ObjectType-Feature-4 ObjectType-Report-1 ObjectType-Article-3 |
ISSN: | 0027-8424 1091-6490 |
DOI: | 10.1073/pnas.88.17.7562 |