[Social cognition disorders in Klinefelter syndrome: A specific phenotype? (KS)]. / Troubles de la cognition sociale dans le syndrome de Klinefelter : un trait phénotypique ?

INTRODUCTION: The Klinefelter syndrome (KS) is a genetic condition characterized by an X supernumerary sex chromosome in males. The syndrome is frequently associated with cognitive impairment. Indeed, the different areas of the executive sphere can be affected such as inhibition, cognitive flexibility but also attentional and visual-spatial domain. Social cognition disorders, predominantly on emotional recognition processes, have also been documented. In addition, the syndrome may be associated with psychiatric symptoms. MATERIAL AND METHOD: Our study aims to characterize of the various components of social cognition in the SK: facial emotional recognition, theory of mind and attributional style. For this two groups (SK group versus control group) of participants (n=16) matched for age and sociocultural level were recruited. Participants with intellectual disabilities, psychiatric or neurological disorders were excluded. Three social cognition tests were available: the TREF, the MASC, the AIHQ. Neurocognitive functions were assessed by the fNart, the subtest "logical memory" of the MEM-III, the subtests of the two VOSP battery, the d2, the TMT and the Stroop test. RESULTS: The SK group had specific social cognition disorders in comparison to the control group. Two emotions in particular were less well recognized: fear and contempt. In addition, the SK group had significantly lower results in theory of mind. Regarding the hostile attribution bias, no significant difference was found. Finally, the results showed correlations between specific attentional disorders and facial emotional recognition. DISCUSSION-CONCLUSION: Our study emphasizes social cognition disorders in SK. These disorders could be considered as a phenotypic trait in the syndrome. The interest of better characterizing the cognitive phenotype of genetic disorders that can affect the neurodevelopment is to offer specific cognitive remediation strategies.

[Smith-Magenis syndrome is an association of behavioral and sleep/wake circadian rhythm disorders]. / Le syndrome de Smith-Magenis, une association unique de troubles du comportement et du cycle veille/sommeil.

Smith-Magenis syndrome (SMS) is a genetic disorder characterized by the association of facial dysmorphism, oral speech delay, as well as behavioral and sleep/wake circadian rhythm disorders. Most SMS cases (90%) are due to a 17p11.2 deletion encompassing the RAI1 gene; other cases stem from mutations of the RAI1 gene. Behavioral issues may include frequent outbursts, attention deficit/hyperactivity disorders, self-injuries with onychotillomania and polyembolokoilamania (insertion of objects into bodily orifices), etc. It is noteworthy that the longer the speech delay and the more severe the sleep disorders, the more severe the behavioral issues are. Typical sleep/wake circadian rhythm disorders associate excessive daytime sleepiness with nocturnal agitation. They are related to an inversion of the physiological melatonin secretion cycle. Yet, with an adapted therapeutic strategy, circadian rhythm disorders can radically improve. Usually an association of beta-blockers in the morning (stops daily melatonin secretion) and melatonin in the evening (mimics the evening deficient peak) is used. Once the sleep disorders are controlled, effective treatment of the remaining psychiatric features is needed. Unfortunately, as for many orphan diseases, objective guidelines have not been drawn up. However, efforts should be focused on improving communication skills. In the same vein, attention deficit/hyperactivity disorders, aggressiveness, and anxiety should be identified and specifically treated. This whole appropriate medical management is underpinned by the diagnosis of SMS. Diagnostic strategies include fluorescent in situ hybridization (FISH) or array comparative genomic hybridization (array CGH) when a microdeletion is sought and Sanger sequencing when a point mutation is suspected. Thus, the diagnosis of SMS can be made from a simple blood sample and should be questioned in subjects of any age presenting with an association of facial dysmorphism, speech delay with behavioral and sleep/wake circadian rhythm disorders, and other anomalies including short stature and mild dysmorphic features.