Association between a point mutation at the -743-bp region of the transthyretin (TTR) gene and familial vitreous amyloidosis.

The aim of this study was to identify changes in the base sequence of the upstream regulatory region of the transthyretin (TTR) gene. Whole-blood DNA was extracted from ten subjects belonging to a family with familial amyloidosis vitreoretinopathy; the upstream regulatory sequence was amplified by polymerase chain reaction, detected by gel electrophoresis, and sequenced. The DNA sequence of the upstream regulatory region of the TTR gene was successfully sequenced, and a point mutation (-743A→T) was identified in six of the ten blood samples: four patients and two family members without disease incidence. Therefore, a point mutation was identified in the upstream regulatory region of the TTR gene in a Han Chinese family with familial vitreous amyloidosis.