Chromosomal sharing in atypical cases of gelatinous drop-like corneal dystrophy

Abstract

In Japanese GDLD patients, phenotypic variability is observed both among and within families in spite of the allelic homogeneity of Q118X. Even in these atypical cases, the patients shared the same chromosomal region, received from a founder.

Novel TACSTD2 mutation in gelatinous drop-like corneal dystrophy

“…The onset of the disease in proband 1 was much earlier than that of his brother and sister, who initially experienced the symptoms in their second decade of life. Similar to the previous study of Tsujikawa et al , 20 we observed high phenotypic variability in a single family with GDLD.…”

Spectrum of Clinical Signs and Genetic Characterization of Gelatinous Drop-Like Corneal Dystrophy in a Colombian Family

“…Because this family is consanguineous, affected individuals are likely to share an extended haplotype at the TACSTD2 locus so genetic variants in the shared genomic interval are unlikely to contribute to the observed phenotypic variability. Similarly, Tsujikawa et al 19 described a homozygous Q118X mutation in 4 Japanese families with inter-and intrafamilial phenotypic variability. Previous reports have indicated that the phenotypic variability for this dystrophy is because of age-related progression over time, as the nodular subepithelial amyloid deposits gradually increase in number and coalesce during the first and second decades of life, 3,9,10 and it remains possible that the milder phenotype observed in some individuals in this family could progress in the next few years or decades.…”

Gelatinous drop-like corneal dystrophy: a review

“…The mutations identified were p.Gln118Ter (Q118X), c.632delA, p.Gln207Ter (Q207X) and p.Ser170Ter (S170X), of which p.Gln118Ter (Q118X) was found to be the most commonly observed mutation 29. Interestingly, their group also demonstrated absence of genetic variability in Japanese patients who presented with phenotypic variations and were clinically initially diagnosed as atypical bilateral amyloidosis 31. The p.Gln118Ter (Q118X) mutation consists of a C→T transition at nt352, replacing the nucleotide sequence codon encoding for glutamine at position 118 with a stop codon, which in turn truncates the protein sequence at that point.…”