<prompt> Retinitis pigmentosa is a feature of all exceptRefsums diseaseHallervorden-Spatz diseaseNARPAbetalipoproteinemia  <response>: Ans is b i.e. Hallervorden-Spatz disease Retinitis pigmentosa is associated with many systemic conditions. These are important as they may be recognized first by an ophthalmologist.Systemic conditions associated with retinitis pigmentosa RP-Bardet-Biedl syndrome: It is characterized principally by retinitis pigmentosa, obesity, polydactyly, mental retardation, hypogonadism, and renal dysfunction.Laurence-Moon-Biedl syndrome: similar to Bardet-Biedl syndrome. In addition to Bardet Biedl syndrome has paraplegia.Ushers syndrome: RP labyrinthine deafnessBassen-Kornzweig disease Abetalipoproteinemia : RP, fat malabsorption, spinocerebellar degeneration, and acanthocytosisKearns-Sayer syndrome: Mitochondrial myopathy characterized by external ophthalmoplegia, lid ptosis, cardiac conduction block mild RP.Cockaynes syndrome: RP, progressive infantile deafness, dwarfism, mental retardation, nystagmus ataxia.Refsums syndrome: RP, peripheral neuropathy, cerebellar ataxia. This is an autosomal recessive hypertrophic neuropathy caused by defective oxidation of phytanic acid, a branched-chain fatty acid found in dairy products, beef, lamb, and fish. The onset is in late childhood or adolescence, with a slowly progressive course of a sensorimotor demyelinating neuropathy with sensorineural deafness, cerebellar ataxia, and anosmia. Retinitis pigmentosa presenting as night blindness often precedes the onset of neuropathyHallgren fs syndrome: RP, vestibulo-cerebellar ataxia, congenital deafness mental deficiencyNeuronal Ceroid Lipofuscinosis: is a devastating condition that involves progressive neurological failure, mental deterioration, seizures, and retinitis pigmentosa. It results from excessive accumulation of lip pigments lipofuscin in the bodys tissues.Olivopontocerebellar degenerationNARP: Neuropathy, ataxia, retinitis pigmentosa, developmental delay, mental retardation, lactic academia Ref: Harrison chapter e39This list has been compiled from the above mention books. Hallervorden-Spatz finds no mention in these books. However on the below mentioned web-addresses, associations have been described with RP. 