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Refsum's Disease
 Childhood onset (< 20 yrs): Classic form
 l Phytanic Acid Oxidase ; Chromosome 10pter-p11.2; Recessive
 Onset
 Night blindness
 5 to 20 years of age
 Demyelinating Neuropathy
 Distribution of signs: Symmetric; Distal progressing to Proximal
 Weakness: Distal; Legs > Arms
 Sensory loss: Vibration & Proprioception > Pain & Temperature
 Tendon reflexes: ê or Absent
 Nerve size: Enlarged in some patients
 Course
 May present subacutely over weeks
 Progressive or Relapsing
 Nerve conduction: Very slow motor & sensory velocity (Some < 10 M/s)
 CSF Protein: Very High
 Nerve pathology
 Hypertrophy: Proximal > Distal
 Onion bulbs: Large
 ê Myelinated axons
 Ultrastructure: Inclusions in Schwann cell cytoplasm
 Cranial nerves
 Anosmia
 Deafness
 CNS
 Clinical: Ataxia
 Pathology: ê Purkinje cells & Neurons in Inferior olive, Dentate, Vestibular, Cochlear & Red nuclei
 Retinitis Pigmentosa
 Granular
 Concentric constriction of visual fields
 ê ERG
 Systemic
 Cardiac Failure: May cause sudden death; Onset after childhood
 Ichthyosis
Diabetes
 Skeletal: Short 4th metatarsal; Epiphyseal dysplasia; Syndactyly
 Biochemistry
 Elevated serum phytanic acid
 Reduced oxidation of phytanic acid in fibroblasts
 Peroxisomal dysfunction
 Treatment: Low phytanic acid diet
 Infantile onset
 l Peroxin-1 ; Chromosome 7q21-q22; Autosomal recessive
 Protein
 Required for peroxisomal matrix protein import
 Genetics
 Homozygous mutation (gly843asp) found in
 Infantile Refsum's & 1 patient with neonatal adrenoleukodystrophy (NALD)
 Heterozygosity for this mutation (? other mutation) found in
 Zellweger's; Neonatal Adrenal Leukodystrophy; Infantile Refsum's
 Clinical
 Mental retardation
 Neuropathy: Demyelinating
 Deafness
 Retinitis pigmentosa
 GI: Hepatomegaly; Steatorrhea
 Skeletal: Facial dysmorphism; Growth failure; Osteopenia
 Biochemistry
 Hypocholesterolemia
 Accumulation of phytanic acid, pipecolic acid, very long chain fatty acids
 Pathology
 CNS: Leukodystrophy
 Peroxisomes: ê or Absent
 Adult onset with increased pipecolicacidemia ;
 l ? Peroxisomal disorder; Chromosome 10p; Recessive
Carbohydrate-deficient glycoprotein syndrome
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