We're unable to sign you in at this time. Please try again in a few minutes.
We were able to sign you in, but your subscription(s) could not be found. Please try again in a few minutes.
There may be a problem with your account. Please contact the AMA Service Center to resolve this issue.
Contact the AMA Service Center:
Telephone: 1 (800) 262-2350 or 1 (312) 670-7827  *   Email: subscriptions@jamanetwork.com
Error Message ......
Original Investigation |

Correlation of Severity of Fuchs Endothelial Corneal Dystrophy With Triplet Repeat Expansion in TCF4

Ahmed Z. Soliman, MD1,2; Chao Xing, PhD3; Salma H. Radwan, MD1,4; Xin Gong, MD2; V. Vinod Mootha, MD2,3
[+] Author Affiliations
1Department of Ophthalmology, Cairo University, Cairo, Egypt
2Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas
3McDermott Center for Human Growth and Development, University of Texas Southwestern Medical Center, Dallas
4Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis
JAMA Ophthalmol. 2015;133(12):1386-1391. doi:10.1001/jamaophthalmol.2015.3430.
Text Size: A A A
Published online

Importance  The CTG18.1 triplet repeat expansion in TCF4 has recently been found to be a common functional variant contributing significant risk to the development of Fuchs endothelial corneal dystrophy (FECD) in Eurasian populations.

Objectives  To determine the effect of the expanded CTG18.1 allele of TCF4 on FECD severity and to correlate CTG triplet repeat allele length to the severity of FECD.

Design, Setting, and Participants  In a cross-sectional analysis, we studied 139 index cases (probands and unrelated individuals) with FECD recruited from a cornea referral practice at the University of Texas Southwestern Medical Center, Dallas, from April 2010 through February 2015. The triplet repeat polymorphism CTG18.1 was genotyped using a combination of short tandem repeat analysis, triplet repeat–primed polymerase chain reaction assay, and Southern blot analysis. Severity of FECD was graded using a modified Krachmer grading system (severity scale of 0-6 based on extent of confluent guttae).

Main Outcomes and Measures  The CTG triplet repeat length of the largest allele was compared with the Krachmer grade of FECD severity, keratoplasty proportion, and central corneal thickness in the white subset.

Results  Eighty-five of 122 white index cases with FECD (69.7%) harbored the triplet repeat expansion. The mean (SD) Krachmer grade was 5.61 (0.76) in the group with the repeat expansion compared with 5.11 (1.05) in the group without the expanded repeats (P = .01). Forty-seven participants with the repeat expansion (55.3%) had undergone keratoplasty at the time of recruitment, compared with 13 (35.1%) of those without the expansion (P = .0497). There was a positive correlation of Krachmer grade to triplet repeat number (P = .002) and a nominal association of the keratoplasty proportion with triplet repeat number (P = .04). The mean (SD) central corneal thickness was 605.9 (50.5) μm in the group with the expanded repeats compared with 581.3 (50.5) μm in the group without the expansion (P = .04).

Conclusions and Relevance  The Krachmer grade of disease severity was greater in FECD cases with the CTG18.1 triplet repeat expansion in TCF4 than in those without the expansion. The CTG triplet repeat allele length was positively correlated with the Krachmer grade of severity. The TCF4 triplet repeat expansion resulted in a more severe form of FECD, with clinical and surgical therapeutic implications.

Figures in this Article

Sign in

Purchase Options

• Buy this article
• Subscribe to the journal
• Rent this article ?


Place holder to copy figure label and caption
Scatterplot Showing the Relationship Between Krachmer Grade and CTG Repeat Length of the Largest Allele

The Spearman rank correlation coefficient was estimated to be 0.27 (P = .002).

Graphic Jump Location




Also Meets CME requirements for:
Browse CME for all U.S. States
Accreditation Information
The American Medical Association is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians. The AMA designates this journal-based CME activity for a maximum of 1 AMA PRA Category 1 CreditTM per course. Physicians should claim only the credit commensurate with the extent of their participation in the activity. Physicians who complete the CME course and score at least 80% correct on the quiz are eligible for AMA PRA Category 1 CreditTM.
Note: You must get at least of the answers correct to pass this quiz.
Please click the checkbox indicating that you have read the full article in order to submit your answers.
Your answers have been saved for later.
You have not filled in all the answers to complete this quiz
The following questions were not answered:
Sorry, you have unsuccessfully completed this CME quiz with a score of
The following questions were not answered correctly:
Commitment to Change (optional):
Indicate what change(s) you will implement in your practice, if any, based on this CME course.
Your quiz results:
The filled radio buttons indicate your responses. The preferred responses are highlighted
For CME Course: A Proposed Model for Initial Assessment and Management of Acute Heart Failure Syndromes
Indicate what changes(s) you will implement in your practice, if any, based on this CME course.


Some tools below are only available to our subscribers or users with an online account.

1 Citations

Sign in

Purchase Options

• Buy this article
• Subscribe to the journal
• Rent this article ?

Related Content

Customize your page view by dragging & repositioning the boxes below.

See Also...
Articles Related By Topic
Related Collections