Genetic Diagnosis To Surgical Outcome: A Case Series Of Macular Corneal Dystrophy In Four Burmese Refugees

Macular Corneal Dystrophy (MCD) is an autosomal recessive (AR) stromal corneal dystrophy with abnormal metabolism of proteoglycans, due to mutations of the Carbohydrate sulfotransferase (CHST6) gene. We present a case of four Burmese refugee siblings that presented with severe MCD due to an inherited CHST6 homozygous pathogenic variant. The siblings report a total of 8 children in their generation, 4 of them having MCD, with unaffected heterozygous parents. Given AR inheritance, the likelihood of this is 8.65%. This report describes the findings on exam/imaging/pathology/genetic testing, treatments, subsequent outcome, and complications of each case.

These patients were evaluated and treated at a university-associated tertiary care center in the United States.

We present the case of four Burmese refugee siblings that presented with severe MCD secondary to an inherited CHST6 homozygous pathogenic variant. The siblings report a total of 8 adult children, 4 of them having MCD, inherited from unaffected heterozygous parents. Given AR inheritance, the chance of this inheritance is 8.65%. This report describes the findings on exam/imaging/pathology/genetic testing, treatments, subsequent outcome, and complications of each case.  

Each of the four patients presented successively across ten years' time. All four affected individuals (3 brothers, 1 sister) underwent diagnostic genetic testing with the 33-gene Invitae Corneal Dystrophies panel. The results identified a homozygous CHST6 pathogenic variant (c.680del). This is a rare frameshift variant that creates a premature translational stop signal (p.Gly227Alafs*154) that has not been previously reported in the literature. The homozygosity suggests a degree of consanguinity in this Burmese family. 

All siblings were diagnosed with severe MCD and elected to undergo PKP in one or both eyes based on individual preference and clinical course. Each underwent standard post operative care following their respective PKP operations including topical steroid and antibiotic drops, and these regimens were altered based on individual post operative courses. Cases were complicated by delayed wound healing and development of open angle or steroid induced glaucoma.

Macular Corneal Dystrophy has certain genetic and geographic patterns. This Burmese sibling cohort (4 of 8 with a homozygous variant) highlights the increased risk of single-gene disorders in consanguineous populations and identifies Myanmar as a potential region of higher prevalence, in addition to other known populations including Saudi Arabia and southern India. Management challenges include delayed wound healing, secondary glaucoma, language barriers, and follow-up difficulties in refugee populations. This series emphasizes the importance of early diagnosis, genetic counseling for families, culturally sensitive care planning, and vigilant post-transplant monitoring to improve outcomes in this progressive, vision-threatening dystrophy.