CHRNA7 and Cognitive impairment: CHRNA7 duplication is however of unknown significance, although cognitive impairment and psychiatric disorders have been observed in several families with such microduplications.41 On the other hand, another individual (UAB-R4613) also with very severe developmental delay (inability to read and write at age 17 and only processing basic information, such as following directions and completing small assignments) had a normal aCGH result.