This Article  • References  • Full text PDF  • Reply to article  • Send to a friend  • Save in My Folder  • Save to citation manager  • Permissions  Citing Articles  • Citation map  • Contact me when this article is cited  Related Content  • Similar articles in this journal  Social Bookmarking   What's this?

A Case Report of Monozygotic Twins Discordant for the Disease

Kailash Bhol, PhD; Ira Udell, MD; Nezam Haider, PhD; Juan J. Yunis, MD; Aloke Mohimen, PhD; Ronald Neuman, MD; Cono Grasso, MD; A. Razzaque Ahmed, MD; Stephen Foster, MD

Arch Ophthalmol. 1995;113(2):202-207.

Abstract
Objective
To identify the major histocompatibility complex markers and the autoantibody associated with ocular cicatricial pemphigoid (OCP) in a proband, her unaffected cotwin, and the children of the cotwin. Ocular cicatricial pemphigoid is a chronic autoimmune disorder that affects the conjunctiva and other squamous epithelium. It is associated with the major histocompatibility complex class II alleles that are presumed to provide enhanced susceptibility to the disease. We encountered a pair of monozygotic female twins, one of whom has OCP. In addition to totally identical physical appearances since birth, the two sisters have identical blood groups.

Methods
The following studies were performed on the patient, her unaffected cotwin sister, and her children: (1) polymorphism of major histocompatibility complex class II genes by DNA typing, (2) sequence analysis of DQβ gene second and third exons, and (3) serologic evaluation for the presence of anti—basement membrane zone autoantibodies specific for OCP by Western immunoblot with the use of skin and conjunctiva lysates as substrates.

Result
Both monozygotic twins had the same HLA haplotypes. The sequence analysis of the second and third exons of DQβ genes revealed no significant differences between the proband and her unaffected cotwin. Autoantibodies specific to OCP were detected only in the patient's serum. The serum of the unaffected cotwin and the other relatives did not demonstrate the presence of the OCP autoantibody.

Conclusion
This isolated family study does not support a single-gene theory for the development of OCP. It is most likely due to a multigene effect and associated with environmental factors.

Author Affiliations
From the Department of Dermatology, Boston (Mass) University School of Medicine (Drs Bhol, Haider, Mohimen, and Ahmed); the Department of Ophthalmology, Long Island Jewish Medical Center, Long Island Campus for Albert Einstein College of Medicine, New Hyde Park, NY (Dr Udell); the Division of Immunogenetics, Dana-Farber Cancer Institute, Department of Pathology (Dr Yunis), and the Massachusetts Eye and Ear Infirmary, Department of Ophthalmology (Drs Neuman and Foster), Harvard Medical School, Boston, Mass; and Catholic Medical Center of Brooklyn-Queens (NY) (Dr Grasso).

CiteULike    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter     What's this?