Optic Nerve Edema, Splenomegaly, Cytopenias
Alternate Names
Defective Genes
Clinical Characteristics
Ocular Features
Persistent optic nerve edema is eventually followed by some degree of optic atrophy. The nerve edema may be seen early in the first decade of life and is not associated with increased lumbar puncture pressure. Peripapillary hemorrhages may be seen. Visual acuity may decrease somewhat by the end of the first decade of life and becomes functionally significant in early adolescence and may be reduced to counting fingers. The ERG, which shows minimal dysfunction early, eventually appears nearly flat without photopic or scotopic responses. The retinal vessels become markedly attenuated and the macula may be mildly edematous and show pigmentary changes. Pigment clumping is not seen. Visual fields show a central or cecocentral scotoma, enlargement of the blind spot, and eventually severe peripheral constriction. The vitreous and aqueous humor sometimes have an increased number of cells. Lenticular opacities requiring cataract surgery has been reported. One patient developed a phacomorphic angle closure attack at the age of 19 years.
Systemic Features
Splenomegaly is a consistent sign and is usually present in the first decade of life but histology shows primarily cellular congestion of the red pulp cords. Bone marrow biopsies show mild erythroid hyperplasia. Peripheral blood counts show mild neutropenia and thrombocytopenia. Occasional atypical lymphocytes may be seen. Patients often complain of mildly to moderately severe migraine headaches. Urticaria and anhidrosis are common features.
Genetics
Inheritance
Only a single report of this condition has been published. A mother and two daughters (half sisters) had the symptoms described here and this is the basis for consideration of autosomal dominant inheritance. Nothing is known regarding the etiology or the mechanism of disease.
Pedigree
Autosomal dominant
Autosomal dominant disorders require only one mutation for the disease to be expressed. Since an affected parent has two chromosomes, only one of which has the mutant gene, parents can expect that half (50%) of their children will receive that one and inherit the disease. It is common for individuals that inherit the mutation, however, to not have evidence of the disease (nonpenetrance).
Autosomal dominant inheritance leads to a vertical pattern of transmission