help button home button Endocrine Society JCEM
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
This Article
Right arrow Full Text (PDF)
Right arrow Submit a related Letter to the Editor
Right arrow Purchase Article
Right arrow View Shopping Cart
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow Request Copyright Permission
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Okamoto, H.
Right arrow Articles by Oiso, Y.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Okamoto, H.
Right arrow Articles by Oiso, Y.

Journal of Clinical Endocrinology & Metabolism, Vol 81, 2204-2208, Copyright © 1996 by Endocrine Society

ARTICLES

Molecular analysis of females manifesting thyroxine-binding globulin (TBG) deficiency: selective X-chromosome inactivation responsible for the difference between phenotype and genotype in TBG-deficient females

H Okamoto, Y Mori, Y Tani, Y Nakagomi, T Sano, K Ohyama, H Saito and Y Oiso
First Department of Internal Medicine, Nagoya University School of Medicine, Japan.

T4-binding globulin (TBG) is the major transport protein of thyroid hormone in man. Inherited TBG abnormalities were manifested fully in hemizygous males and partially in heterozygous females and transmitted in an X-chromosome-linked fashion, compatible with its location on Xq21- 22. We have previously reported that complete deficiency (CD) and partial deficiency (PD) in Japanese subjects resulted from two distinct mutations of the TBG gene, TBG-CDJ and TBG-PDJ, respectively. Recently, we encountered a female manifesting TBG-CD and herein investigated the molecular mechanisms. She was found to possess TBG-CDJ and common-type TBG (TBG-C) alleles by characterizing the TBG gene. Then, X-chromosome inactivation status was evaluated in her family members using a phosphoglycerate kinase (PGK) gene, located on Xq13. Three TBG-CDJ heterozygotes and one unaffected female, confirmed to be PGK heterozygotes for a polymorphic BstXI site, were analyzed. Only the CD female was shown to undergo selective inactivation by examining the BstXI site in amplified products after digestion with a methylation- sensitive enzyme, HpaII. Among an additional eight informative females with TBG deficiency, one heterozygous female for TBG-PDJ shared this selective inactivation pattern. Moreover, the X-chromosome with TBG-C was suggested to be inactivated selectively from the linkage of PGK and TBG alleles recognized in eight of nine family members. Selective X- chromosome inactivation was considered to be the cause of a female heterozygous for TBG-CDJ or -PDJ manifesting the same phenotype as a hemizygote.


This article has been cited by other articles:


Home page
 J. Clin. Endocrinol. Metab.Home page
S. Reutrakul, O. E. Janssen, and S. Refetoff
Three Novel Mutations Causing Complete T4-Binding Globulin Deficiency
J. Clin. Endocrinol. Metab., October 1, 2001; 86(10): 5039 - 5044.
[Abstract] [Full Text] [PDF]

Home page
 J. Clin. Endocrinol. Metab.Home page
G. A. Carvalho, R. E. Weiss, and S. Refetoff
Complete Thyroxine-Binding Globulin (TBG) Deficiency Produced by a Mutation in Acceptor Splice Site Causing Frameshift and Early Termination of Translation (TBG-Kankakee)
J. Clin. Endocrinol. Metab., October 1, 1998; 83(10): 3604 - 3608.
[Abstract] [Full Text]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Endocrinology Endocrine Reviews J. Clin. End. & Metab.
Molecular Endocrinology Recent Prog. Horm. Res. All Endocrine Journals
Copyright © 1996 by The Endocrine Society