von Hippel-Lindau disease type 2A in a family with a duplicated 21-base-pair in-frame insertion mutation in the VHL gene.
BACKGROUND
von Hippel-Lindau disease (VHL), also called angiomatosis retinae, is inherited as an autosomal dominant trait. It is frequently associated with other tumors in the central nervous system, kidneys, or adrenal glands. In order to investigate the relationship between genotype and corresponding phenotypes, we performed molecular genetic analysis in a Japanese patient with VHL type 2A.


METHODS
After informed consent had been obtained, the three exons of the VHL gene were PCR-amplified and sequenced either directly or after subcloning. Clinical features were also examined.


RESULTS
A novel in-frame duplication of the 21 base pairs at nucleotide 806 (the position of codon 198) of the VHL gene was found in our patient. The clinical phenotype of the patient included retinal hemangiomas associated with vitreous hemorrhage and traction retinal detachment, pheochromocytoma, and hemangioma-like lesions in the cerebellum which corresponded to those of VHL type 2A. Abnormal diffuse vascular leakage was observed in the apparently intact retina by fluorescein angiography.


CONCLUSIONS
An insertion mutation of the VHL gene is a rare association with VHL type 2. This insertion mutation may interfere the binding between the VHL gene and elongins. Abnormal retinal vascular leakage suggests the possible effects of overexpressed vascular permeability factors such as vascular endothelial growth factor from hemangiomas associated with defective VHL gene.
Miyagawa
Yasuhiro
Y
Department of Ophthalmology, Hirosaki University School of Medicine, 5 Zaifu-cho, Japan.
Nakazawa
Mitsuru
M
Noda
Yasuko
Y
Ito
Shoichi
S
Ohguro
Hiroshi
H
D000310:Adrenal Gland Neoplasms / Q000235:genetics; D000595:Amino Acid Sequence; D001483:Base Sequence; D004252:DNA Mutational Analysis; D005091:Exons; D005260:Female; D005451:Fluorescein Angiography; D020440:Gene Duplication; D005838:Genotype; D006391:Hemangioma / Q000235:genetics* / Q000473:pathology; D006801:Humans; D008025:Ligases / Q000235:genetics*; D008875:Middle Aged; D008969:Molecular Sequence Data; D009154:Mutation; D010375:Pedigree; D010641:Phenotype; D010673:Pheochromocytoma / Q000235:genetics; D016133:Polymerase Chain Reaction; D019572:Retinal Neoplasms / Q000235:genetics* / Q000473:pathology; D025521:Tumor Suppressor Proteins; D044767:Ubiquitin-Protein Ligases; D014823:Vitreous Hemorrhage / Q000235:genetics; D051794:Von Hippel-Lindau Tumor Suppressor Protein; D006623:von Hippel-Lindau Disease / Q000235:genetics* / Q000473:pathology
D025521:Tumor Suppressor Proteins; D044767:Ubiquitin-Protein Ligases; D051794:Von Hippel-Lindau Tumor Suppressor Protein; D008025:Ligases; C497446:VHL protein, human