Social facilitation of object-oriented hand use in a Rett syndrome variant girl: implications for partial preservation of an hypothesized specialized cerebral network.
Partial preservation of object-oriented hand use (OOHU) was studied behaviorally in a 6-1/2-year-old girl with the preserved speech variant (PSV) of Rett syndrome (RS), associated with a T 158 missense MeCP2 mutation and favorably skewed X-inactivation. At home, OOHU was limited except for self-feeding. When examined, overall time invested in toy play was only 38% of that of healthy subjects, and also, by comparison with healthy subjects, less when autonomous than when socially-facilitated (13% vs 63%). Good interest in and responsiveness to people translated into better motivation for OOHU. She responded to others' requests for grasping and handling objects and used them to reinforce affiliations with people. Results were discussed in terms of a disruption of the formation of a specialized OOHU cerebral network in RS, partially compensated for by the favorably skewed X-inactivation, which among other effects permitted functional retention of the network segment incorporating social influence and motivation.
Umansky
R
R
Child Development Center, Children's Hospital, Oakland, California 94618, USA. umanskyb@lanminds.com
Watson
J S
JS
Hoffbuhr
K
K
Painter
K M
KM
Devaney
J
J
Hoffman
E
E
D002648:Child; D002868:Chromosomal Proteins, Non-Histone; D004268:DNA-Binding Proteins / Q000235:genetics; D005260:Female; D020868:Gene Silencing; D006801:Humans; D051783:Methyl-CpG-Binding Protein 2; D020125:Mutation, Missense; D011596:Psychomotor Disorders / Q000175:diagnosis / Q000235:genetics / Q000534:rehabilitation*; D012056:Reinforcement, Social; D012097:Repressor Proteins; D015518:Rett Syndrome / Q000175:diagnosis / Q000235:genetics / Q000534:rehabilitation*; D012932:Social Facilitation; D014960:X Chromosome
D002868:Chromosomal Proteins, Non-Histone; D004268:DNA-Binding Proteins; C497392:MECP2 protein, human; D051783:Methyl-CpG-Binding Protein 2; D012097:Repressor Proteins