Intellectual impairment is not commonly a feature of Turner syndrome

I thank Chua and colleagues for their review of anaesthesia for strabismus surgery.¹ It is a welcome update on the subject.

However, I would like to draw attention to Table 2, which lists under Turner syndrome ‘intellectual impairment’ as the first clinical feature. This is largely incorrect.

Ninety percent of women and girls with Turner syndrome have average or above average intellect. ² While the incidence of specific learning deficiencies, especially in visuospatial processing or some difficulties in social development, has been reported to fall between 30% and 79% in Turner syndrome, only a minority have true ‘intellectual impairment’. ³ It is unlikely that minor learning difficulties such as ‘impaired use of non-verbal behaviours’ (which is similar to that seen in high-functioning autism) experienced by the women and girls with Turner syndrome will impact upon their anaesthetic care.

By contrast, for people with Apert syndrome the incidence of intellectual disability falls within the 30%–79% range ⁴ and for those with Crouzon syndrome the incidence falls in the 5%–29% range, ⁵ yet this is not listed at all in the same table.

Finally, and in addition, the term ‘mental retardation’ (Table 2, Cri du chat syndrome) ¹ was dropped from the Diagnostic and Statistical Manual of Mental Disorders, version 5 (DSM-V) and the International Classification of Disease, version 11 (ICD-11) in 2013 ⁶ in favour of the far less pejorative ‘intellectual disability’.