LONGITUDINAL-STUDY OF THE COGNITIVE-DEVELOPMENT IN CHILDREN WITH WILLIAMS-BEUREN SYNDROME

Crisco [1990: Clin Res 38:536A] reported stability of IQs in a group o f 14 children with Williams-Beuren syndrome (WBS) over a Ei-year perio d and concluded that they display a development rate similar to normal children. The aim of our study was to examine the stability of the de velopment of nonverbal reasoning abilities over a period of 2 years us ing two methods. We studied 18 children with WBS (9 girls, 9 boys) wit h a mean age of 6.6 years (range: 4.4-10.6 yr) at year one (T1), and a pproximately two years later (T2) at the average age of 8.6 years (ran ge: 5.11-12.7 yr), The Columbia Mental Maturity Scale (CMM) and the Dr aw A Person Test were administered. The results show that the IQs resu lting from the Draw A Person Test were stable over the 2-year period ( T1: mean IQ = 63.5, T2: mean IQ = 65, t = 0.63), and display a signifi cant correlation between the two methods (r = 0.547, P = 0.01). Furthe rmore, the correlation between the two tests (CMM and Draw A Person Te st) at the second assessment is high and significant (r = 0.56, P = 0. 01). The mean IQs at T2 can be classified as mild mental retardation. A notable result is the significant decrease of the IQs according to t he CMM (T1: mean IQ = 77, T2: mean IQ = 68, t = 2.69, P = 0.01). These results suggest that the developmental outcome of children with WBS v aries in specific areas of cognitive function over a 2-year period. (C ) 1996 Wiley-Liss, Inc.