BACKGROUND: It is not known whether those with co-morbid fragile X syndrome (FXS) and autism represent a distinct subtype of FXS; whether the especially severe cognitive delays seen in studies of young children with co-morbid FXS and autism compared with those with only FXS continue into adolescence and young adulthood; and whether autism in those with FXS is 'true autism', i.e. reflects the same underlying problems as idiopathic autism. METHOD: We compared the non-verbal IQ of adolescents and young adults with co-morbid FXS and autism (n = 10) with those with only FXS (n = 44). We then created a subsample of those with FXS only, matched on non-verbal IQ, mental age and gender (n = 21) to the subsample of those with co-morbid FXS and autism. We compared the two groups on measures of expressive language, receptive language (lexical, grammatical morphology and syntactic patterns), and a theory of mind task. RESULTS: Those with co-morbid FXS and autism had lower non-verbal IQs than those with only FXS. The participants with co-morbid FXS and autism did not perform as well as the cognitive ability- and gender-matched participants with only FXS on the three measures of receptive language or the theory of mind task; there were no differences on the expressive language measure. CONCLUSIONS: Our findings support the notion that those with co-morbid FXS and autism represent a distinct subtype of FXS, with more impairment in receptive language and theory of mind even when controlling for their lower non-verbal IQ relative to those with only FXS. The greater cognitive impairments observed in those with co-morbid FXS and autism continues into adolescence and young adulthood; and the autism seen in those with FXS appears to be the same as idiopathic autism.
BACKGROUND: It is not known whether those with co-morbid fragile X syndrome (FXS) and autism represent a distinct subtype of FXS; whether the especially severe cognitive delays seen in studies of young children with co-morbid FXS and autism compared with those with only FXS continue into adolescence and young adulthood; and whether autism in those with FXS is 'true autism', i.e. reflects the same underlying problems as idiopathic autism. METHOD: We compared the non-verbal IQ of adolescents and young adults with co-morbid FXS and autism (n = 10) with those with only FXS (n = 44). We then created a subsample of those with FXS only, matched on non-verbal IQ, mental age and gender (n = 21) to the subsample of those with co-morbid FXS and autism. We compared the two groups on measures of expressive language, receptive language (lexical, grammatical morphology and syntactic patterns), and a theory of mind task. RESULTS: Those with co-morbid FXS and autism had lower non-verbal IQs than those with only FXS. The participants with co-morbid FXS and autism did not perform as well as the cognitive ability- and gender-matched participants with only FXS on the three measures of receptive language or the theory of mind task; there were no differences on the expressive language measure. CONCLUSIONS: Our findings support the notion that those with co-morbid FXS and autism represent a distinct subtype of FXS, with more impairment in receptive language and theory of mind even when controlling for their lower non-verbal IQ relative to those with only FXS. The greater cognitive impairments observed in those with co-morbid FXS and autism continues into adolescence and young adulthood; and the autism seen in those with FXS appears to be the same as idiopathic autism.
Authors: Elizabeth M Berry-Kravis; Lothar Lindemann; Aia E Jønch; George Apostol; Mark F Bear; Randall L Carpenter; Jacqueline N Crawley; Aurore Curie; Vincent Des Portes; Farah Hossain; Fabrizio Gasparini; Baltazar Gomez-Mancilla; David Hessl; Eva Loth; Sebastian H Scharf; Paul P Wang; Florian Von Raison; Randi Hagerman; Will Spooren; Sébastien Jacquemont Journal: Nat Rev Drug Discov Date: 2017-12-08 Impact factor: 84.694
Authors: Elizabeth Berry-Kravis; David Hessl; Leonard Abbeduto; Allan L Reiss; Andrea Beckel-Mitchener; Tiina K Urv Journal: J Dev Behav Pediatr Date: 2013-09 Impact factor: 2.225
Authors: R Nick Hernandez; Rachel L Feinberg; Rebecca Vaurio; Natalie M Passanante; Richard E Thompson; Walter E Kaufmann Journal: Am J Med Genet A Date: 2009-06 Impact factor: 2.802