Objective: Syndromes with genetically determined retinal diseases and concurrent multiple neurologic abnormalities are rare. Kjellin described an autosomal recessive entity with spastic paraplegia, mental retardation, amyotrophia, and macular dystrophy. We sought to further characterize the retinal phenotype and to contrast fundus changes and the genotype to Stargardt's disease in a young patient with progressive Kjellin's syndrome.
Design: Observational case report and family genetic study.
Patients: One affected and 11 unaffected members of a family with Kjellin's syndrome were investigated.
Methods: Complete ophthalmologic and neurologic examinations were performed, including electrophysiologic evaluation, color vision assessment, fundus autofluorescence, and fluorescence angiography. To investigate a possible role of the ABCA4 gene in the etiology of the macular changes, the entire 50 coding exons, including flanking intronic sequences of the patient, were analyzed by direct sequencing.
Main outcome measures: The patient was evaluated for her symptoms, retinal function, fundus autofluorescence, angiography, and mutations in the ABCA4 gene.
Results: A 27-year-old female patient initially was seen with trembling of her right hand. Subsequently, progressive paraspasticity occurred, and a diagnostic workup revealed mild mental retardation. Biomicroscopy disclosed symmetric multiple round yellowish flecks at the level of the retinal pigment epithelium scattered at the posterior pole, which showed increased intrinsic fluorescence in the center, with a halo of reduced autofluorescence. Multifocal electroretinography elicited abnormal responses in the macular area in the presence of normal Ganzfeld electroretinography recordings. In gene mapping, several common variants were identified, although none seem to be associated with the disease features.
Conclusions: Macular changes in Kjellin's syndrome share phenotypic characteristics with Stargardt's disease, although there are differences with regard to appearance, distribution, angiographic, and autofluorescence behavior of the retinal flecks. Ophthalmologic examination is prudent in patients with similar neurologic deficits, because it is essential for the diagnosis and because visual symptoms may be absent even in the presence of obvious and widespread retinal manifestations. The abnormal gene product in Kjellin's syndrome seems to cause progressive dysfunction in various neuronal tissues but seems to be distinct from the major defect underlying the Stargardt's disease phenotype.