Autism may have two distinct subtypes based on brain connectivity patterns

Amazing stuff! I procrastinated on blogging about this one!

"... Some neuroscientists have been exploring the possibility that this well-documented diversity partly reflects differences in the brain's organization and underlying neurobiology. However, so far only a few studies have been able to link differences in autistic behavior to specific neurobiological processes. ...

Their findings ... led to the identification of two distinct autism subtypes characterized by distinct connectivity patterns. ...

"Autism is extremely heterogeneous clinically, and for many years imaging studies have also reported heterogeneous and sometimes apparently conflicting findings: some studies found reduced functional connectivity, others found increased connectivity, and others found more complex patterns. ..."

From the abstract:

"It is often assumed that phenotypic heterogeneity in autism reflects underlying pathobiological variation. However, direct evidence supporting this link is lacking. Leveraging cross-species functional neuroimaging, we show that brain dysconnectivity patterns in autism can be parsed into biologically dissociable subtypes.

Specifically, we found that functional magnetic resonance imaging (fMRI) connectivity alterations in 20 distinct genetic mouse models of autism cluster into hypoconnectivity-dominant and hyperconnectivity-dominant subtypes.

These subtypes are linked to distinct biological pathways, with hypoconnectivity being associated with synaptic dysfunction and hyperconnectivity reflecting transcriptional and immune-related alterations.

Here we identified analogous hypoconnectivity and hyperconnectivity subtypes in a multicenter human fMRI dataset of n = 940 individuals with idiopathic autism and n = 1,036 neurotypical individuals. The human autism subtypes are highly replicable, are associated with distinct functional network architectures and behavioral profiles and recapitulate the synaptic and immune-related pathways identified in the rodent dataset.

Our work provides a new empirical framework for targeted subtyping of the autism spectrum."

Autism may have two distinct subtypes based on brain connectivity patterns

Nature Neuroscience: Autism subtypes identified using cross-species functional connectivity analyses "It is often assumed that phenotypic heterogeneity in autism reflects underlying pathobiological variation. However, direct evidence supporting this link is lacking. Leveraging cross-species functional neuroimaging, we show that brain dysconnectivity patterns in autism can be parsed into biologically dissociable subtypes."

Autism subtypes identified using cross-species functional connectivity analyses (open access)

Fig. 1: fMRI connectivity in 20 autism mouse models clusters into dominant hypoconnectivity and hyperconnectivity subtypes.