Abstract
Purpose:
Knobloch syndrome is an autosomal recessive vitreo-retinal degeneration,associated with high myopia, perinuclear lens opacity, ectopia lentis and an occipital defect. Mutations in COL18A1 and ADAMTS18 are responsible for the disease. This is a case report of familiar Knobloch syndrome associated with terminal transverse defect.
Methods:
A complete systemic and ophthalmologic evaluation for phenotypic characterization was done.
Results:
The proband is a female patient, 10 years old, with high myopia, congenital cataract and vitreo-retinal degeneration with myopic fundus. Also she had an occipital defect and left arm with terminal transverse defect. There were two sisters with similar phenotypical ophthalmic characteristics. One of them 9 years old with high myopia, poor pupillary dilation, smooth iris, perinuclear lens opacity, inferotemporal ectopia lentis, and retinal detachment in left eye. The other one, 6 years old, with high myopia, congenital cataract and strabismus. There was no consanguinity and parents were healthy.
Conclusions:
Knobloch syndrome is a very distinctive ocular phenotype with vitreo-retinal degeneration and abnormalities of iris and lens. It is different from other congenital vitreoretinopathies because of the autosomal recessive pattern and association with occipital encephalocele. As far as we know the terminal transverse defect has not been associated with the disease. Occipital encephalocele is variable in presentation, therefore, ophthalmologists must be able to diagnose this disease recognizing the characteristic ocular abnormalities.