Clinical and behavioral characteristics in FG syndrome

FG syndrome is a rare X-linked recessive form of mental retardation, first described by Opitz and Kaveggia in 1974. Based on over 50 reported cases, F G syndrome is associated with agenesis of the corpus callosum, minor facial anomalies (high, broad forehead with frontal cowlick, ocular hypertelorism , down-slanted palpebral fissures, and small cupped auricles), relative mac rocephaly, broad thumbs and halluces, and prominent fetal fingertip pads. A ffected individuals manifest neonatal hypotonia and severe constipation, wh ich usually resolves during mid-childhood. The hypotonia with joint hyperla xity evolves into spasticity with joint contractures in later life. Affabil ity, hyperactivity, and excessive talkativeness are noted frequently in pat ients with FG syndrome. Recently, we described three additional families (s ix additional patients) with FG syndrome who support the localization of a gene for the FG syndrome in chromosome region Xq12-q21 [Graham JM dr, Tacke ls D, Dibbern K, Superneau D, Rodgers C, Coming K, Schwartz CE. 1998. Am J Med Genet 80:145-156.]. Using these same families and one additional sporad ic case of FG syndrome, we compared behavioral and personality characterist ics of 6 FG boys with other boys with syndromic and nonsyndromic mental ret ardation: eight with Down syndrome, seven with Prader-Willi syndrome, eight with nonspecific mental retardation, and 13 with Williams syndrome. Using the Vineland Adaptive Behavior Scales, the Reiss Personality Profiles, and the Achenbach Child Behavior Checklist, parents were asked to characterize the behavior and personality of their boys from ages 4 to 10 years. When co mpared with Williams syndrome, the FG boys had fewer internalizing behavior s and were significantly less anxious and withdrawn but had similar sociall y oriented, attention-seeking behaviors. On the Reiss Profile, FG boys were also quite similar to Williams syndrome boys. On the Vineland Scales, FG b oys demonstrated significant relative strengths in their socialization skil ls, consistent with their personality, tending to confirm previous descript ions of their personalities. (C) 1999 Wiley-Liss, Inc.