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What is Retinitis pigmentosa is a feature of all except - and explain in detail?
Retinitis pigmentosa has features of : 1.Refsum's syndrome. It is characterised by retinitis pigmentosa, peripheral neuropathy and cerebellar ataxia. 2.Usher's syndrome. It includes retinitis pigmentosa and labyrinthine deafness. 3.Hallgren's syndrome. It comprises retinitis pigmentosa, vestibulocerebellar ataxia, congenital deafness and mental deficiency. 4. Other associated syndromes include Bussen- Koranzweig syndrome (Abetalipoproteinaemia), Kearns-Sayer syndrome, Friedreich's ataxia, Bardet-Biedle syndrome, NARP (neuropathy, ataxia, and retinitis pigmentosa), neuronal ceroid lipofuscinosis, olivopontocerebellar degeneration. Ref AK khurana 6/e p 289