ERK inhibitor compounds alone or in combination that prevent abnormalities in neuronal connectivity； or a pharmaceutically acceptable salt and / or one or more stereoisomers thereof； for use in the treatment of fragile X chromosome syndrome or autism spectrum disorders associated with ERK abnormalities, in which the ERK inhibitor is selected from the group consisting of 2- (2-amino-3- methoxyphenyl) - 4H-chromen-4-one, (2Z, 3Z) -bis {amino [(2-aminophenyl) sulfanyl] methylidene} butanedinitrile, 5 - [(4-bromo-2-chlorophenyl) amino] -4-fluoro-N- (2-hydroxyethoxy) -1-methyl-1H-benzimidazol-6-carboxamide, 2 - [(2-fluoro-4-iodophenyl) amino] - N- (2-hydroxyethoxy) -1,5-dimethyl-6-oxo -1,6-dihydropyridin-3-carboxamide, 2- (4-chloro-2-fluoro-anilino) -N- (2-hydroxyethoxy) -1,5-dimethyl-6-oxo-pyridin-3-carboxamide, 2 - [(2-Chloro-4-iodophenyl) amino] -N- (cyclopropylmethoxy) -3,4-difluorobenzamide, (3R, 4R) -4- (3,4-Dimethoxybenzyl) -3- (4-hydroxy-3 -methoxybenzyl) dihydrofuran-2 (3H) -one, (2Z) -3-amino-3 - [(4- aminophenyl) sulfanyl] -2- [2- (trifluoromethyl) phenyl] prop-2-enenitrile, hypericin, 3 - (3-amino-2H-pyrazolo [3,4-c] pyridazin-5-yl) -2-phenyl-3H-pyrazolo [1,5-a] pyridin-8-io, and 2-chloro-4 acid - {[2 - {[(2R) -1-hydroxy- 3-methylbutan-2-yl] amino} -9- (propan-2-yl) -9 Hpurin-6-yl] amino} benzoic.Compuestos inhibidores de ERK en solitario o en combinación que evitan anomalías en la conectividad neuronal； o una sal farmacéuticamente aceptable y/o uno o más estereoisómeros de los mismos； para su uso en el tratamiento de síndrome del cromosoma X frágil o trastornos del espectro autista asociados a anomalías de ERK, en los que el inhibidor de ERK se selecciona entre el grupo que consiste en 2-(2-amino-3- metoxifenil)-4H-cromen-4-ona, (2Z,3Z)-bis{amino[(2-aminofenil)sulfanil]metilideno}butanodinitrilo, 5-[(4-bromo-2- clorofenil)amino]-4-fluoro-N-(2-hidroxietoxi)-1-metil-1H-bencimidazol-6-carboxamida, 2-[(2-fluoro-4-yodofenil)amino]- N-(2-hidroxietoxi)-1,5-dimetil-
