Posterior column ataxia-retinitis pigmentosa syndrome (PCARP) is an

autosomal recessive In genetics, dominance is the phenomenon of one variant (allele) of a gene on a chromosome masking or overriding the effect of a different variant of the same gene on the other copy of the chromosome. The first variant is termed dominant and ...

genetic disorder of the human eye, attributed to mutation of a gene originally dubbed AXPC1 which was identified as a mutation in the FLCVR1 gene. Generally rare, a

Pennsylvania Pennsylvania (; (Pennsylvania Dutch: )), officially the Commonwealth of Pennsylvania, is a state spanning the Mid-Atlantic, Northeastern, Appalachian, and Great Lakes regions of the United States. It borders Delaware to its southeast, Ma ...

Mennonite Mennonites are groups of Anabaptist Christian church communities of denominations. The name is derived from the founder of the movement, Menno Simons (1496–1561) of Friesland. Through his writings about Reformed Christianity during the Ra ...

variant has been estimated to have a population allele prevalence close to 1% due to

founder effect In population genetics, the founder effect is the loss of genetic variation that occurs when a new population is established by a very small number of individuals from a larger population. It was first fully outlined by Ernst Mayr in 1942, usi ...

Clinical phenotype

The syndrome was described having childhood-onset symptoms with

sensory neuropathy Peripheral neuropathy, often shortened to neuropathy, is a general term describing disease affecting the peripheral nerves, meaning nerves beyond the brain and spinal cord. Damage to peripheral nerves may impair sensation, movement, gland, or or ...

characterized by

proprioceptive Proprioception ( ), also referred to as kinaesthesia (or kinesthesia), is the sense of self-movement, force, and body position. It is sometimes described as the "sixth sense". Proprioception is mediated by proprioceptors, mechanosensory neuron ...

loss with

retinitis pigmentosa Retinitis pigmentosa (RP) is a genetic disorder of the eyes that causes loss of vision. Symptoms include trouble seeing at night and decreasing peripheral vision (side and upper or lower visual field). As peripheral vision worsens, people may ...

presenting with concentric

visual field The visual field is the "spatial array of visual sensations available to observation in introspectionist psychological experiments". Or simply, visual field can be defined as the entire area that can be seen when an eye is fixed straight at a point ...

loss. By adulthood patients were blind with

ataxia Ataxia is a neurological sign consisting of lack of voluntary coordination of muscle movements that can include gait abnormality, speech changes, and abnormalities in eye movements. Ataxia is a clinical manifestation indicating dysfunction of t ...

References

{{Reflist Channelopathies Blindness Disorders of choroid and retina Autosomal recessive disorders