PSYCHOMETRIC STUDIES ON A GIRL WITH 47,XX,+21 DOWN'S SYNDROME AND NEAR-NORMAL INTELLIGENCE

Abstract

Observations have been made on a 6 1/2 year old girl with 47, XX,+21 Down's syndrome on whom the following IQ scores have been obtained: 104 (Goodenough Scale), 80 (Stanford-Binet) and 77 (Wechsler Intelligence Scale for Children). Performance IQ on the Wechsler was 90. She was tested between kindergarten and first grade (public school) with the Wide Range Achievement Test and scored within the first grade level in spelling and reading. Concentration and short term memory were in the superior range. Performance subtest scores on the WISC ranged from 7 to 12 (12 on Coding). Her remarkable achievement on the WISC Coding A test was primarily the result of her memorizing quickly the five double symbol associations. She regularly defeats her mother in the card game “Concentration”. Twenty-five cells were analyzed from a leucocyte culture and all showed an extra chromosome in the G group. No euploid cells were seen. G-banding identified the extra chromosome to be a no. 21. A skin culture was unsuccessful. Appearance was quite typical of Down's syndrome with bilateral epicanthal folds, severe clinodactyly and hypoplastic ears. More detailed psychometric studies seem indicated on those trisomy-21 children in the highest range of performance in order to define their areas of strength, as well as to aid in sorting out familial factors vs. environment in terms of the etiology of the “gifted trisomy-21 child.