A new GRN variant in logopenic variant primary progressive aphasia: a case report and literature review

The majority of genetic Primary progressive aphasia (PPA) patients harbor mutations in the granulin (GRN) gene. The present case showed impaired performances in single-word retrieval in spontaneous speech and naming, and repetition. Head MRI revealed marked lateral atrophy in the left parietal cortex. A diagnosis of logopenic variant PPA (lvPPA) was established. Genetic analysis showed a heterozygous 10-bp frameshift deletion in exon 4 of the GRN gene (NM_002087.4), leading to transformation of cysteine into alanine at amino acid 92 and creation of a premature stop codon at position 161. This patient represented a rare case of GRN-associated lvPPA. A new mutation site was detected in exon 4 of GRN gene.