The early detection of mental retardation.
D002648:Child; D002657:Child Development; D002675:Child, Preschool; D008040:Genetic Linkage; D006801:Humans; D007223:Infant; D008607:Intellectual Disability / Q000175:diagnosis* / Q000209:etiology / Q000235:genetics / Q000378:metabolism / Q000503:physiopathology; D007804:Language Development; D009048:Motor Skills; D009129:Muscle Tonus; D014960:X Chromosome