Regarding the primary outcome of psychological and learning capabilities , both studies assessed the effect of interventions on  children 's verbal and non-verbal intellectual functioning using the Wechsler Intelligence Scale for Children - Revised .
AUTHORS ' CONCLUSIONS Low- quality evidence from two small trials showed that when compared to placebo , LAC may not improve intellectual functioning or hyperactive behaviour in children with FXS
BACKGROUND People with fragile X syndrome ( FXS ) have an intellectual dysfunction that can range from very mild to severe .
Symptoms can include speech and language delays and behavioural difficulties such as aggression or self injurious behaviours , emotional lability , and anxiety-related problems ( for example obsessive-compulsive symptoms and perseverative behaviours ) .
In some cases , affected people may have an additional diagnosis of attention deficit hyperactivity disorder or an autism spectrum disorder .
OBJECTIVES To review the efficacy and safety of L-acetylcarnitine in improving the psychological , intellectual , and social performance of people with FXS .
[L-acetylcarnitine treatment on fragile X patients hyperactive behaviour].
Hyperactivity is a significant problem for almost all young males affected by fragile X syndrome ( FXS ) , the most common inherited disease causing mental retardation . Therapeutical approaches are actually based on Central Nervous System ( CNS ) stimulants lacking a well defined rationale and efficacy while they further decrease the patient 's limited attention span . A pilot study on 17 fragile X male treated with L-acetylcarnitine ( LAC ) over one year , showed a significant reduction of their hyperactivity behaviour tested by the Conners Abbreviated Parent-Teacher Question naire . LAC use in FXS patients derives from the hypothesis that the biochemical and physiological properties this substance has may preserve brain activity . LAC is a small , hydrosoluble molecule that easily diffuses in the extracellular space and enters any cell in the nervous system through specific transporters . Different cerebral areas use this molecule differently to metabolize glucose and lipids to provide for ATP and neurotrasmitters synthesis . The acetyl group LAC carriers represents a key metabolic signaling element possibly mediating its effect in the CNS . The exogenous administration of LAC may affect brain activity in FXS by : I ) modulation of fuel partitioning for energy production , which at the mithocondrial level is associated with the Kreb 's cycle metabolic role in neurotransmitter synthesis ; II ) remodelling of lipid membrane in terms of LAC actively determining the production of polyunsaturated fatty acids ; III ) preferential effect on the attention component of the cholinergic system which relies on its peculiar modality of communication in the CNS . Based on the above premises an explorative , double-blind , placebo controlled , multicenter study is ongoing . A total population of 160 children from nine European centers will be enrolled . The objective of this study is to determine the effect of LAC on the hyperactive behaviour of FXS children as evaluated by the administration of the Conners Abbreviated Parent Question naire
Regarding the primary outcome of psychological and learning capabilities , both studies assessed the effect of interventions on  children 's verbal and non-verbal intellectual functioning using the Wechsler Intelligence Scale for Children - Revised .
AUTHORS ' CONCLUSIONS Low- quality evidence from two small trials showed that when compared to placebo , LAC may not improve intellectual functioning or hyperactive behaviour in children with FXS
BACKGROUND People with fragile X syndrome ( FXS ) have an intellectual dysfunction that can range from very mild to severe .
Symptoms can include speech and language delays and behavioural difficulties such as aggression or self injurious behaviours , emotional lability , and anxiety-related problems ( for example obsessive-compulsive symptoms and perseverative behaviours ) .
In some cases , affected people may have an additional diagnosis of attention deficit hyperactivity disorder or an autism spectrum disorder .
OBJECTIVES To review the efficacy and safety of L-acetylcarnitine in improving the psychological , intellectual , and social performance of people with FXS .