title: A Case ofTransforming Growth Factor-β-InducedGene-Related Oculorenal Syndrome: Granular Corneal Dystrophy Type II with a Unique Nephropathy.
abstract: Many types of inherited renal diseases have ocular features that occasionally support a diagnosis. The following study describes an unusual example of a 40-year-old woman with granular corneal dystrophy type II complicated by renal involvement. These two conditions may coincidentally coexist; however, there are some reports that demonstrate an association between renal involvement and granular corneal dystrophy type II. Granular corneal dystrophy type II is caused by a mutation in thetransforming growth factor-β-induced (TGFBI)gene. The patient was referred to us because of the presence of mild proteinuria without hematuria that was subsequently suggested to be granular corneal dystrophy type II. A kidney biopsy revealed various glomerular and tubular basement membrane changes and widening of the subendothelial space of the glomerular basement membrane by electron microscopy. However, next-generation sequencing revealed that she had no mutation in a gene that is known to be associated with monogenic kidney diseases. Conversely, real-time polymerase chain reaction, using a simple buccal swab, revealedTGFBIheteromutation (R124H). The TGFBI protein plays an important role in cell-collagen signaling interactions, including extracellular matrix proteins which compose the renal basement membrane. This mutation can present not only as corneal dystrophy but also as renal disease.TGFBI-related oculorenal syndrome may have been unrecognized. It is difficult to diagnose this condition without renal electron microscopic studies. To the best of our knowledge, this is the first detailed report of nephropathy associated with aTGFBImutation.
authors: Department of Internal Medicine, Koseiren Sanjo General Hospital, Sanjo, Japan.
authors: Yoichi
authors: Y
authors: Iwafuchi
authors: Department of Internal Medicine, Kidney Center, Shinrakuen Hospital, Niigata, Japan.
authors: Tetsuo
authors: T
authors: Morioka
authors: Department of Internal Medicine, Koseiren Sanjo General Hospital, Sanjo, Japan.
authors: Yuko
authors: Y
authors: Oyama
authors: Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan.
authors: Kandai
authors: K
authors: Nozu
authors: Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan.
authors: Kazumoto
authors: K
authors: Iijima
authors: Division of Clinical Nephrology and Rheumatology, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.
authors: Ichiei
authors: I
authors: Narita
keywords: Extracellular matrix; Granular corneal dystrophy type II; Next-generation sequencing; Oculorenal syndrome; Protein-protein interactions; Transforming growth factor-β-induced gene