[Cognitive aspects in girls with fragile X syndrome]

Fragile X syndrome (FXS) is the first cause of intellective dysfunction due to hereditary reasons, but above all it is a multisystemic pathology, in which the cognitive behavioural phenotype is going to mark the child's entire school and social life. An early diagnosis is fundamental for proper genetic counselling and for the pedagogical approach. In girls, this diagnosis is hindered by a poorer knowledge of the semiology and because of the variability of the symptoms. Recognising the most significant clinical signs that suggest a diagnosis during early childhood is fundamental.

An analysis of the literature offered us very few reports of girls affected by FXS and most of them are to be found in publications about genetics. There is often no clear separation between adulthood and childhood or between permutation and complete mutation, and extreme shyness and low self esteem are the most commonly reported data. Intellective capacity is normal in 40% of those affected by complete mutation; the pragmatic aspects of language and difficulties at school that can take on symptoms of non verbal learning disorder are the most significant data at school age; the incidence that the number of CGG repetitions, the degree of methylation and the FMR protein rate can have on both the symptomatology and the intensity with which they appear do not offer any homogeneous data; the attitude of the school and familial environment is a factor that has recently been considered to be of great importance in the maintenance or improvement of behavioural aspects.

Although the discovery of the FMR1 gene provided us with a greater understanding of the symptomatology of FXS in girls, the scarcer knowledge available about its manifestations means that we can find ourselves before the problem of possibly mistaking it for learning disorders. The greater variability of its clinical symptoms and the shortage of studies that have appeared in publications on paediatrics and neuropaediatrics may be the underlying reason behind this lack of knowledge. Spanish language publications practically ignore cases of girls with FXS.