Extending the phenotype of posterior column ataxia with retinitis pigmentosa caused by variants in FLVCR1.

Posterior column ataxia with retinitis pigmentosa (PCARP) is a rare autosomal recessive condition due to variants in the Feline Leukemia Virus Subgroup C Cellular Receptor 1 (FLVCR1) gene which was first described in 1997. In this article, we describe a young female patient with a childhood diagnosis of retinitis pigmentosa and learning disability, presenting with progressive ataxia from her late teens. Examination revealed spastic lower limbs with absent reflexes, and reduced vibration and joint position sensation. Magnetic resonance imaging showed normal cerebellar volume and linear signal abnormality within the posterior columns of her spinal cord. Trio exome analysis confirmed two variants in FLVCR1. Our case extends the phenotype of PCARP to include learning disability and developmental delay, and highlights the importance of considering this rare condition in young adults or children with visual impairment and ataxia.