Friday, 1 March 2013

The common ground

Today's post is all about common ground. I'm not necessarily making a plea for common ground to be found in any specific area or community, but rather how the concept of common ground runs through a few important discussions which I recently found interesting.

A short while ago the BBC ran with the headline 'Five psychiatric disorders linked' built on the study findings reported by the Cross-Disorder Group of the Psychiatric Genomics Consortium* (et al?) published in The Lancet. The authors findings, discussed shortly, highlighted: "the goal of moving beyond descriptive syndromes in psychiatry, and towards a nosology informed by disease cause". Shared genes (or at least shared SNPs) and common ground.

Next was the very interesting blog post from Tom Insel at the NIMH titled 'The Four Kingdoms of Autism'. In it, Dr Insel quite cleverly describes the four big schools of autism thought: illness, identity, injury and insight, based on how autism is represented, and how "as long as each kingdom stays behind its own walls, there is little hope for progress overall". I'm not normally too interested in discussing non peer-reviewed blog posts here, but there was something about this entry, which many people probably had thought about but have never really put into words, as a consequence of the very, very wide heterogeneous spectrum that is autism and the resultant views about that spectrum. Dr Insel's solution: "to find some common ground where the entire community can work together".

Back to the Lancet paper. As with other high-profile results discussed in quite a few online outlets, there is little point in me regurgitating what has already been said. To summarise: based on a huge bank of cases of people diagnosed with conditions like autism, ADHD, schizophrenia, bipolar disorder and major depressive disorder (n=33,332), "genome-wide single-nucleotide polymorphism (SNP) data" were analysed and compared with an equally large bank of asymptomatic (at least for these conditions) control samples (n=27,888). The results: the single letter genetic glitches - SNPs - which we all have scattered throughout our genome, seemed in the symptomatic group to congregate in some cases more frequently in parts of the genome associated with these overlapping conditions. Ergo, SNPs in certain genes seemed to do more for uniting these conditions over dividing them to varying degrees.

I hope I'm not over-exaggerating things when I say that the Lancet study is potentially really quite a big deal. Regular readers might know that I'm quite interested in the whole comorbidity side of things when it comes to autism, and how the presentation of autism is so much more than the sum of the triad (dyad). That for example, the risk of overlap between autism and schizophrenia spectrums is an area of considerable interest and how modern medicine has chosen to compartmentalise many of these 'overlapping' conditions are important parts of this debate. Indeed, not wishing to glorify Dr Insel, but the issue of classification has also cropped up previously on his blog too (see here).

Granted, I'm not totally sold on the idea that SNPs are the magical 'be-all-and-end-all markers' of conditions like autism (or ADHD or anything else) given that (a) things are complicated when it comes to genes and mutation as I found out on a recent post looking at HERVs and autism, (b) related to (a), that new sheriff in the town of -omics called epigenetics which might imply other influences on the expression of the genome, and (c) the various gaps in the genomic work including the phrase 'de novo' when it comes to mutations, which is just a little bit too nebulous for me in terms of these SNPs just spontaneously appearing. What is described as spontaneous now, might not be so described in 10 or 20 years time.

But that's not to say that the science of genes is all bunk. Indeed, the very nice systems biology that it starting to filter through this area of endeavour, realising that genes are not just coding proteins for one specific system in the brain for example, is for me a step in the right direction. Also it appears flowing from the Lancet paper force with their use of the term 'pathway analyses' and the potential link with "calcium-channel activity genes" for example, which have been mentioned before with conditions like autism in mind** (open-access).

I'd like to think that the Lancet paper and Insel post whilst dealing with quite different material, reflect the principle of common ground when it comes to appreciating that the real-life presentation and manifestation of autism or ADHD or schizophrenia are not just diagnostic criteria in a textbook. Alongside, realising that blanket debates such as 'disorder or difference' where autism is concerned, while emotive and dependent to some extent where you come from and your own experiences, tend to take little consideration of the wide, very wide, heterogeneity present in conditions like autism. I can't say that there is an easy solution to bringing such a debate to resolution but at least some writers are thinking about this issue.


* Cross-Disorder Group of the Psychiatric Genomics Consortium. Identification of risk loci with shared effects on five major psychiatric disorders: a genome-wide analysis The Lancet. February 2013.

** Lu. A et al. Support for calcium channel gene defects in autism spectrum disorders. Molecular Autism 2012; 3: 18.

---------- Cross-Disorder Group of the Psychiatric Genomics Consortium (2013). Identification of risk loci with shared effects on five major psychiatric disorders: a genome-wide analysis The Lancet DOI: 10.1016/S0140-6736(12)62129-1