The name is absent

Autism prodrome 36 of 89

Pickles et al. found a strong association between age of first words and likelihood of
undergoing regression. That is, frank loss of language skills was associated with
switching from the most advanced early language to being amongst the slowest (in
terms of eventual onset of phrase speech). They conclude that regression might be
more common than currently recognized; with whatever neurodevelopmental
perturbation that is occurring being unrecognized by parental observation. However,
the challenge would then be to understand what the nature and causes of the
underlying perturbation in these cases is. In common with most others investigating
regression, this study relied on retrospective parental report many years after the
phenomenon of investigation; limiting our confidence to draw strong conclusions
from these data until they are corroborated (or not) in prospective studies.

In addition to our discussion of retrospective and prospective studies
pertaining to behavioral and biological early markers that may be associated with the
prodrome/s of ASD we now move on to discuss issues related to perinatal
developments and genetics as these contribute to risk and vulnerability to develop
ASDs.

Perinatal Risk Factors

Although the genetic basis for ASDs is supported by various genetic studies
(Bailey et al., 1995; Gupta & State, 2007; Muhle, Trentacoste, & Rapin, 2004; Risch et
al., 1999), current estimates of ASD prevalence are 1 in 100 to 1 in 150 (Baird et al.,
2006; CDC, 2007), indicating that the prevalence of autism and related ASD is
substantially greater than previously recognized. Thus, it has been suggested that one or
more environmental triggers may be contributors (Bello, 2007). It is reasonable to
assume that both environmental and heritable factors contribute risk to ASD and there
is increasing recognition that environment in addition to genes needs to be considered

<<   33   34   35   36   37   38   39   >>

More intriguing information