Patients 5 and 6, 44 years old (CDR-SB 1.5, MMSE 30) and 58 years old (CDR-SB 1, MMSE 27) respectively, both carried a splice site mutation (IVS 10 + 16) associated with 4R tau, presented with mild cognitive impairment (MCI). This evidence concerns the gene MAPT and Cognitive impairment.