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SIR–Although an apparently normal early development had initially been regarded as one of the criteria for Rett syndrome, various scientists considered the disorder to be developmental, manifesting shortly after birth.1–5 The only objective evaluation of possible behavioural anomalies before diagnosis, and especially before regression, consists of a thorough analysis of family videos from the first year(s) of the females’ lives. Based on this methodological approach, we recently reported on the neuromotor development of a female with the preserved speech variant of Rett syndrome (PSV), providing evidence that this variant, too, manifests itself within the first months of life.6

PSV, a mild variant with better speech, language, and motor abilities, recently attracted a great deal of attention when it was suggested that it should be relabelled as Zappella variant7 so that it would refer to the eponymous author who first described this phenotype.8,9 This prompted us to take a close look at video footage of the early speech and language functions of a female who had been diagnosed with PSV at the age of four. Consent for publication of the analysis of this footage was given by the parents.The comprehensive video footage of the female gave a deep insight into the speech and language acquisition processes symptomatic of this variant. The meticulous analyses of 443 minutes of family videos, including 170 minutes (57 different clips) before regression, disclosed a behavioural pattern that had not been described so far: as the main characteristic feature of the pre-regression period, which lasted for 24 months, typical age-specific communicative behaviour turned out to be interspersed with atypical patterns; most strikingly, normal babbling was interrupted by modulated inspiratory vocalizations. Nonetheless, the female reached some milestones of early language acquisition (babbling, gestures, first words), followed by a massive deterioration and eventual loss of communicative functions and withdrawal from social life (between ages 2 and 4). Her language then started to recover in such a way that, by now, aged 11, she has managed to re-acquire a set of relatively complex communicative skills, albeit with deficiencies and idiosyncrasies on all linguistic levels (phonology, morphosyntax, semantics, and pragmatics).

On the basis of our findings we state our position as follows: (1) Compared with other phenotypes of Rett syndrome, some communicative deficiencies in females with PSV can be classified as relatively mild; compared with typical language acquisition and capacities, the communicative abilities of females with PSV are clearly deviant in terms of quality. (2) The individual trajectory attests to an atypical ontogenetic pathway from the pre-linguistic stage onwards; communicative functions are lost to a large extent. (3) As opposed to other neuromotor and cognitive functions, speech and language abilities are not preserved to a higher extent. These results suggest that the appropriateness of the term preserved speech is relative and support the proposal of relabelling the variant.7 For the time being, it remains an open question whether early inspiratory vocalizations are syndrome-specific or share characteristics with other neurodevelopmental disorders.

Acknowledgements

  1. Top of page
  2. Acknowledgements
  3. References

Austrian Science Fund (FWF; P19581-B02), the Lanyar Foundation (P325, P337), and the Theodor Koerner Fund.

References

  1. Top of page
  2. Acknowledgements
  3. References