A variant in GRN of Spanish origin presenting with heterogeneous phenotypes

INTRODUCTION

The variant c.1414-1G>T in the GRN gene has previously been reported as probably pathogenic in subjects of Hispanic origin in the American continent.

METHODS

We report 5 families of Spanish origin carrying this variant, including the clinical, neuroimaging, and laboratory findings.

RESULTS

Phenotypes were strikingly different, including cases presenting with behavioral variant frontotemporal dementia, semantic variant primary progressive aphasia, rapidly progressive motor neuron disease (pathologically documented), and tremor-dominant parkinsonism. Retinal degeneration has been found in homozygous carriers only. Ex vivo splicing assays confirmed that the mutation c.1414-1G>T affects the splicing of the exon, causing a loss of 20 amino acids in exon 11.

CONCLUSIONS

We conclude that variant c.1414-1G>T of the GRN gene is pathogenic, can lead to a variety of clinical presentations and to gene dosage effect, and probably has a Spanish founder effect.

[Retinitis pigmentosa in an adolescent]

BACKGROUND

Retinitis pigmentosa is the most common chronic and inherited condition of retinal dystrophy. The progressive involvement of retinal photoreceptors and other layers characterize this condition. This situation results in optic disc pallor and retinal pigment deposition vascular attenuation.

CASE REPORT

We present the case of a 15-year-old male with a history of 6 months evolution characterized by night blindness and bilateral impairment of superior temporal vision.

CONCLUSIONS

This type of dystrophy is a genetic and progressive eye condition that begins during adolescence and produces visual impairment.