Skorodumova LO, Grafskaia EN, Kharlampieva DD, Maltsev DI, Petrova TV, Kanygina AV, Fedoseeva EV, Makarov PV, Malyugin BE. TACSTD2 in gelatinous drop-like corneal dystrophy: variant functional analysis and expression in the cornea after limbal stem cell transplantation.
Hum Genome Var 2024;
11:26. [PMID:
39013858 PMCID:
PMC11252363 DOI:
10.1038/s41439-024-00284-x]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2024] [Revised: 06/04/2024] [Accepted: 06/05/2024] [Indexed: 07/18/2024] Open
Abstract
Gelatinous drop-like corneal dystrophy (GDLD) is a rare autosomal recessive eye disease. GDLD is characterized by the loss of barrier function in corneal epithelial cells (CECs) and amyloid deposition due to pathogenic variants in the TACSTD2 gene. Limbal stem cell transplantation (LSCT) has been suggested as an effective therapeutic alternative for patients with GDLD. However, despite LSCT, amyloid deposition recurs in some patients. The pathogenesis of recurrence is poorly studied. We present the case of a patient with GDLD. Genetic analysis revealed a homozygous deletion, NM_002353.3:c.653del, in the TACSTD2 gene. Functional analysis in a cell model system revealed the loss of the transmembrane domain and subcellular protein mislocalization. The patient with GDLD underwent direct allogeneic LSCT with epithelial debridement followed by deep anterior lamellar keratoplasty 10 months later due to amyloid deposition and deterioration of vision. Taken together, the results of transcriptome analysis and immunofluorescence staining of post-LSCT corneal sample with amyloid deposits obtained during keratoplasty demonstrated complete restoration of wild-type TACSTD2 expression, indicating that donor CECs replaced host CECs. Our study provides experimental evidence that amyloid deposition can recur after LSCT despite complete restoration of wild-type TACSTD2 expression.
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