A longitudinal study of language development in two children with Williams syndrome.

Williams syndrome (WS) is often cited as the prime example within developmental disorders of the dissociation of language from other cognitive skills, particularly from visuo-motor skills. This claim has been responsible for the challenges posed by this population to cognitive theories and to models of language acquisition. Two Hebrew-speaking children with WS were followed longitudinally for 18 months, from the first occurrences of two word combinations. Y was 3.9-5.3 and BT was 4.2-5.8 during data collection. Both children had an MLU of 1.8-2.8. The children's linguistic profiles were compared to the profiles of typically-developing (TD) children of similar MLU as well as to the profiles of 11 children with a variety of neurodevelopmental disorders (ND), matched on MLU. The profiles exhibited by the children with WS throughout the period of the study differed from the profiles seen in both control groups.