Posterior column ataxia with retinitis pigmentosa coexisting with sensory ‐autonomic neuropathy and leukemia due to the homozygous p.Pro221Ser FLVCR1 mutation

We report the unique case of a 33‐year‐old Italian woman with a combination of typical PCARP, sensory‐autonomic neuropathy with sensory loss to all modalities and multiple autonomic dysfuctions, and acute lymphocytic leukemia. Molecular analysis demonstrated homozygosity for the previously identified FLVCR1 p.Pro221Ser variation. The same variation, in combination with a frameshift mutation, was previously identified in an Italian child with HSAN. Functional studies carried out on patient‐derived lymphoblastoid cell lines showed decreased FLVCR1a transcript, increased reactive oxygen species, excessive intracellular heme accumulation, and increased number of Annexin V positive cells. This indicates that the homozygous p.Pro221Ser FLVCR1 variation compromises the ability of FLVCR1a to export heme leading to enhanced susceptibility to programmed cell death. Our study demonstrates the existence of a phenotypic continuum among the discrete disorders previously linked to FLVCR1 mutations, and suggests that the related alteration of heme metabolism may lead to the degeneration of specific neuronal cell populations.

Source: American Journal of Medical Genetics Part B: Neuropsychiatric Genetics - July 1, 2017 Category: Genetics & Stem Cells Authors: Marco Castori, Silvia Morlino, Martin Ungelenk, Davide Pareyson, Ettore Salsano, Paola Grammatico, Emanuela Tolosano, Ingo Kurth, Deborah Chiabrando Tags: RESEARCH ARTICLE Source Type: research