Histopathologically: total derangement of cortical cytoarchitecture with severe degeneration of white matter. Clinically: rapid psychomotor deterioration, ataxia, and muscular hypotonia; microcephaly and myoclonic jerks are also features
. This has led some to use the term early onset severe retinal dystrophy (EOSRD) to describe severe rod-cone dystrophies of infantile onset.
The main differential diagnosis is from other causes of infantile nystagmus [14, 76] particularly early onset static retinal conditions such as congenital stationary night blindness  and the various forms of achromatopsia . The clinical features, and in particular the ERG findings, allow these disorders to be distinguished from LCA. Although most children with LCA have disease confined to the eye; there are a number of recessively inherited systemic disorders such as Joubert syndrome, and the peroxisomal disorders in which an early onset retinal dystrophy similar to LCA may form part of the syndrome (Table 10.1). Usually the other systemic findings allow these disorders to be distinguished from LCA but in some disorders, for example Alstrom syndrome  and juvenile nephronothisis [7,30,132] the systemic features may not become apparent until later childhood.
Was this article helpful?