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The article identifies the genetic mutations of the XLRS1 gene and describes the ocular phenotypes in two unrelated Thai patients with X-linked juvenile retinoschisis. Mutation screening identified two point mutations, with the first proband developing vitreous hemorrhage in both eyes and the second proband developing slightly blurred vision at age 10 years. The researchers detected foveal and peripheral schisis, and fundus examination revealed the presence of fine white dots at the macula. The probands showed eletronegative electroretinography (ERG).

Background: To identify genetic mutations of the VMD2 gene in two Thai families with Best macular dystrophy. Materials and Methods: Ophthalmic examination including best-corrected visual acuity (BCVA), dilated fundus examination and fundus photography, and electro-oculography (EOG) was performed in two probands and their family members. Mutation screening of the VMD2 gene was performed by single-strand conformation polymorphism (SSCP) analysis followed by direct DNA sequencing of the abnormal exons. Results: The 58-year-old male proband demonstrated typical egg yolk-like macular lesion in both eyes. Mutational screening of VMD2 identified a band shift in exon 7, which was confirmed by direct DNA sequencing to be a G to A transition at position 724 bp. This novel missense mutation resulted in the change of an amino acid valine to methionine and was responsible for the abnormal Arden ratio in the proband's daughter. The second male proband age 25 had a characteristic egg yolk-like macular lesion in the left eye and a scrambled egg appearance in the right. Mutation analysis identified a C to T transition at position 652 bp in exon 6. This reported missense mutation led to an amino acid substitution of cysteine for arginine. The mutation was documented in the maternal grandmother, the mother, as well as the elder sister of the proband. Conclusions: The Val-242-Met mutation is associated with a late-onset visual disturbance and the Arg-218-Cys mutation was associated with marked intra-familial clinical variability of expression. Presymptomatic testing will be available to the family members at risk with high accuracy. [ABSTRACT FROM AUTHOR]

Purpose: To describe the ophthalmic findings and mutation analyses of the PAX6 gene in Thai aniridia patients. Methods: Ten patients from six unrelated families underwent a comprehensive ophthalmic examination. Mutations in the PAX6 gene were screened by single-strand conformational polymorphism (SSCP) and direct DNA sequencing of the SSCP variants. Results: Seven patients developed cataracts and six developed glaucoma. Mutation analysis demonstrated four different truncating mutations, two of which were de novo. These included one novel insertion/deletion mutation (c.474del12insGA in exon 5) and three nonsense mutations. R203X and R240X are common recurrent mutations, while Q277X in exon 10 is novel. All mutations resulted in loss of function of the PAX6 protein. Conclusion: Our data confirm inter- and intrafamilial variable phenotypic manifestations of which the underlying mechanisms may be haploinsufficiency or dominant-negative mutation. [ABSTRACT FROM AUTHOR]