Longer brainstem auditory evoked response latencies of individuals with fragile X syndrome related to sedation

Brainstem auditory evoked response latencies were studied in 75 males (13 with fragile X syndrome, 18 with mental retardation due to other causes, and 44 with no disability). Latency values were obtained for each ear for the positive deflections of waves I (P1), III (P3), and V (P5). Some individuals with mental retardation required sedation. Contrary to previous report, latencies obtained for individuals with fragile X did not differ from those obtained for persons without mental retardation. Persons receiving sedation, whether or not their retardation was due to fragile X, had longer latencies for wave P5 than persons who did not receive sedation. This effect of sedation may also explain the previously reported increased latencies for persons with fragile X. Am. J. Med. Genet. 74:167–171, 1997. © 1997 Wiley‐Liss, Inc.