None at present. Poor fetal movement may occur. The information below has been drawn up by Dr Orlee Udwin of the Society for the Study of Behavioural Phenotypes. Psychological and Behavioural Characteristics Prader-Willi Syndrome is characterised by a number of distinctive psychological and behavioural features. These speech production problems are likely to be due at least partly to the early hypotonia and also the facial abnormalities associated with the syndrome.
Spoken language is often considerably poorer than comprehension of language.
Overall, cognitive abilities range from moderate learning difficulties through borderline abilities to average abilities or better, but usually with multiple learning disabilities. Severe learning difficulties are not commonly found. The children tend to have an unusual cognitive profile, with particular strengths in visual organisation and perception, and in academic achievement tasks such as reading and vocabulary. Unusual skill with jigsaw puzzles is often noted. In contrast, auditory information processing and sequential processing are relatively weak, and most individuals have specific difficulties with arithmetic, writing, visual and auditory short-term memory and auditory attention.