Homozygous MTHFR C667T carriers ≤45 years old develop central retinal vein occlusion five years earlier than wild type

ABSTRACT

Purpose

To assess age at 1^st central retinal vein occlusion (CRVO) in carriers ≤ 45 years old of the methylenetetrahydrofolate reductase (MTHFR) C667T genotype compared to heterozygous and wild type, and to identify predictors of age at CRVO.

Methods

Retrospective cohort study consisting of 18 MTHFR TT, 23 MTHFR TC and 28 MTHFR CC participants; information regarding age, sex, age at CRVO, history of dyslipidaemia, hypertension, smoking and plasma HC measured by immunoassay were collected.

Results

Age at CRVO was lower in MTHFR TT than MTHFR TC and CC (32 ± 6 vs 38 ± 5 vs 37 ± 6 years, respectively, p = 0.005); plasma HC was higher in MTHFR TT than in the other genotypes [14.4 (10.8, 19.6) vs 10.4 ((8.6,12.5) vs 8.5 ((7.5,9.8) μmol/l, p = 0.0002). Smoking (cigarettes/day) independently predicted age at CRVO (p = 0.039) and plasma HC (p = 0.005); smoking status (yes/no) predicted ischemic CRVO (p = 0.01) that was more common in the MTHFR TT group (p = 0.006).

Conclusions

Carriers of the MTHFR TT genotype ≤ 45 years old develop their 1^st CRVO on average 5 years earlier than the MTHFR CC genotype; smoking contributes to the prematurity and severity of CRVO in MTHFR TT carriers.

KEYWORDS:

• Retinal vein occlusion
• methylenetetrahydrofolate reductase
• homocysteine
• smoking

Acknowledgments

Supported by www.fondazioneaps.org an Italian Registered Charity.

Disclosure statement

The authors report no conflicts of interest. The authors alone are respon-sible for the content and writing of this article.

Author contributions

All authors participated in the conception and design of the study. PRJA, VM and FG retrieved the data; GD, LI and AA performed the laboratory tests; PRJA and MM run the statistical analysis; MM and FG wrote the first draft of the manuscript, subsequently reviewed by all authors and finalized by PRJA. All authors read and approved the final manuscript.

Ethics approval and informed consent to participate in the study

At the time of the original study patients gave informed and written consent to the use and storage of their genetic material and of their anonymized clinical information as per approval of the local Ethics Committee.

Additional information

Funding

The author(s) reported there is no funding associated with the work featured in this article.