The association between repeat number in C9orf72 and phenotypic variability in Turkish patients with frontotemporal lobar degeneration.

Frontotemporal lobar degeneration (FTLD) describes a group of progressive brain disorders. The expansion of a noncoding GGGGCC (G4C2) hexanucleotide repeat in the C9orf72 gene is a major cause of both familial FTLD and amyotrophic lateral sclerosis. The aim of this study was to determine the prevalence of C9orf72 G4C2-repeat expansion in a Turkish population with FTLD and to determine its effects on the phenotype. The G4C2 expansion in the C9orf72 gene was analyzed in 100 cases of FTLD without mutations of the MAPT, PGRN, CHMP2B, VCP, TARDBP, and FUS genes and 100 age-matched healthy controls by using repeat-primed polymerase chain reaction and fragment length analysis techniques. A possible pathogenic repeat (≥30) was found in one of the familial cases (1/33), but none of the sporadic cases. The difference in the allele length between the cases and controls was statistically significant (p < 0.01). Intermediate (20-30) repeats were detected in 4% of our cases. Patients with psychotic symptoms appear to be enriched for intermediate and possibly pathogenic repeats. To determine whether the intermediate and ≥30-repeat allele carriers shared the C9orf72 risk haplotype, we examined rs4879515 and rs3849942 in all samples and family members of patients with possibly pathogenic alleles. We identified at least one risk allele for each single-nucleotide polymorphism in all intermediate and possibly pathogenic repeat carriers. We observed that ≥8 unit repeats were strongly correlated with the tagging risk alleles for both single-nucleotide polymorphisms (p < 0.001). To our knowledge, this is the first study to evaluate C9orf72 G4C2 repeats in Turkish patients with FTLD. The present findings suggest that pathogenic expansions of the C9orf72 repeat are uncommon in Turkish patients with FTLD, but intermediate repeats may be a risk factor for FTLD and act as a genetic modifying factor for psychotic symptoms.

Test your memory-Turkish version (TYM-TR): reliability and validity study of a cognitive screening test.

BACKGROUND/AIM: The test your memory (TYM) is reported to be a sensitive cognitive function assessment scale for people with dementia. The aim of the present study was to investigate the reliability and validity of an adapted Turkish version of the TYM (TYM-TR) among Turkish dementia patients. MATERIALS AND METHODS: The TYM-TR was given to 59 patients with dementia aged 60+ and 336 normal controls aged 23-75+. The diagnostic utility of the TYM-TR was compared with that of the mini-mental state examination (MMSE) to validate it. RESULTS: The internal consistency of the TYM-TR was a = 0.85. The test-retest reliability was 0.97 (P < 0.001). The TYM-TR showed a statistically significant correlation with MMSE; r (57) = 0.628 P < 0.001. The TYM-TR distinguished dementia patients from controls (AUC = 0.994). A cut-off point of 34 was optimal for detecting dementia with a sensitivity of 96.61% and a specificity of 96.13% [95% CI (0.981-0.999)]. CONCLUSION: The Turkish version of the TYM was found to have good reliability and validity to distinguish dementia in the Turkish population.