Abstract: | We report an analysis of reading and spelling processes in a case of developmental disability associated with a genetic anomaly (Klinefelter XXXY syndrome). The results are interpreted within the framework of a model of reading and spelling development (Frith, 1985). An almost complete absence of alphabetic functions was noted. Reading appeared to be based on a ‘logographic lexicon’ (Seymour & Elder, 1986), and spelling on a letter sequence generator which was modifiable by access to a limited store of word images. |