Retinitis Pigmentosa with Ataxia

Clinical Characteristics
Ocular Features: 

Pigmentary retinopathy has been noted by 6 months of age. Typical symptoms of retinitis pigmentosa are reported by early childhood.  The visual fields are progressively constricted and a ring scotoma can be plotted.  Night blindness and visual acuity loss are evident in the first decade of life and progressively worsen leading to severe handicaps by the third.  Fundus pigmentation in the midperiphery becomes more prominent and in at least some patients the pattern consists of typical bone spicules.  Cellophane maculopathy has been described.

Systemic Features: 

Proprioceptive deficits and areflexia appear in early childhood and ataxia worsens as individuals mature.  Scoliosis and general weakness and wasting become prominent manifestations.  Sensory neuropathy with loss of vibratory and position sense, astereognosia, and agraphesthesia can become apparent in the first decade of life.  Walking is delayed and gait abnormalities are clearly evident by the second decade leading to orthopedic deformities such as scoliosis.  Unassisted walking becomes impossible.  The intrinsic hand and foot muscles also have mild weakness.  Sural nerve biopsy may reveal loss of large myelinated fibers.  Hyperintense signals in the posterior spinal columns can be seen on MRI.  No anatomic changes have been described in the cerebrum or cerebellum.

Genetics

This is an autosomal recessive disorder resulting from homozygous mutations in FLVCR1 (1q32.2-q41).  This disorder has some clinical similarities to Biemond 1 syndrome but differs in the inheritance pattern and the molecular basis.

Treatment
Treatment Options: 

No specific treatment is available but physical therapy and low vision aids may improve the quality of life.

References
Article Title: 

References

Rajadhyaksha AM, Elemento O, Puffenberger EG, Schierberl KC, Xiang JZ, Putorti ML, Berciano J, Poulin C, Brais B, Michaelides M, Weleber RG, Higgins JJ. Mutations in FLVCR1 cause posterior column ataxia and retinitis pigmentosa. Am J Hum Genet. 2010 Nov 12;87(5):643-54.

PubMedID: 21070897

Higgins JJ, Morton DH, Patronas N, Nee LE. An autosomal recessive disorder with posterior column ataxia and retinitis pigmentosa. Neurology. 1997 Dec;49(6):1717-20.

PubMedID: 9409377