Cross-sectional analysis of speech and cognitive performance in 32 patients with classic galactosemia

Background Long-term outcome in classic galactosemia is disappointing with impaired IQ, reduced bone mineral density, and fertility problems. Moreover, speech impairment is common with conflicting reports regarding frequency, pattern, and relation to IQ. Objective To evaluate speech and cognitive performance in patients with galactosemia. Methods Speech performance was evaluated by means of the Hierarchische Wortlisten, a German word-repetition test for the diagnosis of apraxia of speech, using real words and pseudo-words. Cognitive performance was evaluated by use of age-appropriate German versions of the Wechsler Scales. Results In a cohort of 32 patients (12 females, 20 males; mean age 21.2 ± 7.2 years) with classic galactosemia, the mean IQ was 76.2 ± 14.8. Eighty-four percent of the patients passed the speech test with errors. Speech errors were much more related to pseudo-words than real words and were predominantly observed in words with three and four syllables. The performance in producing words was correlated to the IQ scores. Conclusion Impairment of speech affects a significant number of patients with galactosemia, appears in early childhood, and persists into adulthood. The pattern of speech impairment may allow labeling as apraxia of speech. In many cases impaired speech is related to decreased IQ.