Gelatinous drop-like corneal dystrophy with a novel mutation of TACSTD2 manifested in combination with spheroidal degeneration in a Chinese patient.
OBJECTIVE
To report the clinicopathological findings of a Chinese patient with an unusual phenotype of gelatinous drop-like corneal dystrophy (GDLD) combined with spheroidal degeneration and to detect molecular defect in the tumor-associated calcium signal transducer 2 (TACSTD2) gene.


METHODS
Extensive physical and ophthalmologic examination of the patient was performed. Initially superficial keratectomy was performed for both eyes. Due to recurrence of the corneal opacity, penetrating keratoplasty for the right eye and deep lamellar keratoplasty for the left eye were performed. The obtained corneal tissues were examined by light microscopy. Molecular genetic analysis consisted of PCR amplification and direct automated sequencing of the complete coding region of TACSTD2.


RESULTS
Slit-lamp biomicroscopy of the patient revealed bilateral band-like corneal opacities composed of brown-yellow, oily appearing droplets at the first visit. Two years after superficial keratectomy, elevated mulberry-like gelatinous lesions companied with brown-yellow droplets in the superficial cornea in both eyes were found. Histological analysis of corneal tissue revealed subepithelial amorphous deposits stained positively with Congo red, typical of GDLD. Meanwhile, eosinophilic globular deposits with irregular peripheral margins and various sizes, which were characteristics of spheroidal degeneration, were found. Sequencing of TACSTD2 from the patient revealed a novel homozygous missense mutation c.354G>C, leading to amino acid substitution Q118H in the patient.


CONCLUSIONS
This is the first report indicating a new type of gelatinous drop-like corneal dystrophy (GDLD) combined with spheroidal degeneration. Molecular analysis demonstrated a novel mutation in TACSTD2, which may expand the spectrum of mutations in TACSTD2.
Zhang
Bei
B
Department of Ophthalmology and Sir Run Run Shaw Institute of Clinical Medicine, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Zhejiang, PR China.
Yao
Yu-Feng
YF
D000293:Adolescent; D000951:Antigens, Neoplasm / Q000235:genetics*; D044466:Asian People / Q000235:genetics*; D001483:Base Sequence; D015815:Cell Adhesion Molecules / Q000235:genetics*; D002681:China; D003062:Codon / Q000235:genetics; D003317:Corneal Dystrophies, Hereditary / Q000150:complications* / Q000235:genetics* / Q000473:pathology / Q000628:therapy; D004252:DNA Mutational Analysis; D005780:Gelatin; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics*; D012162:Retinal Degeneration / Q000150:complications* / Q000235:genetics*; D055815:Young Adult
D000951:Antigens, Neoplasm; D015815:Cell Adhesion Molecules; D003062:Codon; C499380:TACSTD2 protein, human; D005780:Gelatin
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