Gelatinous drop like dystrophy (GDLD) in a Sudanese patient

Abstract Purpose Gelatinous drop‐like corneal dystrophy (GDLD) (OMIM #204870) is an early‐ onset, autosomal recessive corneal dystrophy, reported globally. It presents in the first decade of life with bilateral, mulberry‐like or gelatinous lesions, due to amyloid deposition in the superficial cornea. Methods A 50 year old Sudanese patient was diagnosed for GDLD. The patient had penetrating keratoplasty in the right eye. The tissue was processed for light and electron microscopy. A DNA sample was screened for 333 sequence variants in 13 corneal dystrophy genes by Asper Ophthalmics Ltd, followed by confirmatory sequencing. Results The GDLD cornea contained deposits of amyloid fibrils at the sub‐epithelial region and in various parts of stroma. The deposits were Congo red positive and showed apple green birefringence under polarized light. The growth of amyloid fibrils was associated with large splits between lamellae, a reduced diameter of collagen fibrils and degeneration of keratocytes. A homozygous c.355T>A mutation in exon 1 of the TACSTD2 (M1S1) gene was identified, not present in dbSNP, predicted to cause a pathogenic amino acid change (p.Cysl19Ser in NCBI entry NP_002344.2). Conclusion The cornea of this GDLD patient with a novel c.355T>A mutation in exon 1 of TACSTD2 showed degeneration of the corneal epithelium, Bowman’s layer, stroma and keratocytes. Deposits of amyloid were found in the sub‐epithelium region, Bowman’s layer, and stroma. Acknowledgement: Supported by National Plan for Science and Technology, KSU, Riyadh.