In his latest paper on the issue of geneticization, Adam Hedgecoe explores the expansion of the cystic fibrosis (CF) continuum (Hedgecoe 2003), drawing on my previous paper on the relationship between CF and a form of male infertility called Congenital Bilateral Absence of the Vas Deferens (CBAVD) (2000). He extends my story beyond the 1990s, noting some recent disagreements about the expansion of CF to include CBAVD. He suggests, however, that these debates have recently ‘died down’ (2003: 59) and he reiterates the main argument in my earlier paper, stressing ‘the nosological expansion of the disease to include a certain form of male infertility’ (Hedgecoe 2003: 50).

The bulk of his analysis is based upon a review of two articles concerning CF (Davis, Drumm and Konstan 1996 and Stern 1997) and an outline of several discursive strategies that make a link between CF and male infertility in these papers. He supplements this with discussion of other more recent articles on the classification of CF (such as Stuhrmann and Dörk 2000, Rosenstein and Cutting 1998, Bush and Wallis 2000) and similar work on the link between CF and pancreatitis (e.g.Cohn et al. 1998). Referring to my earlier work, Hedgecoe also states that the fact that ‘we both reached largely the same position regarding the expansion of CF classification supports both our individual approaches’ (2003: 53).

I beg to differ. Whilst I must thank Hedgecoe for his generous acknowledgement of my 2000 paper, I am uneasy about the ways in which he has interpreted and developed my work. Although we both focused upon CF and CBAVD, my analysis stopped at 1999. I based my paper upon a thorough analysis of 80 papers published during the 1990s. I argued that the establishment of the CF clinical continuum involved dynamic processes of expansion and contraction and significant levels of interpretative flexibility and I noted in the conclusion of my paper that, in relation to CF overall, the clinical continuum between CF and CBAVD was a minor theme. The interviews that I have since conducted with CF clinicians and scientists, and my on-going analysis of the history of CF1, have underscored my sense that the continuum I described was but one part of a much larger picture where ‘What is CF?’ seems to be a perennial question, before and during the molecular era. This work also leads me to the view that, if there has been a change since the 1990s, it is that debates about the link between CF and CBAVD have intensified, so much so that the continuum between CF and CBAVD now seems to be contracting.

Hedgecoe's version of the continuum does not engage with these changes. He seems to bracket uncertainty as a kind of ‘side-effect’ of geneticization. I also find the implications of Hedgecoe's analysis worrying. He seems to be suggesting that molecular genetics engendered a kind of paradigm-shift in CF workers’ understanding of CF and that this has resulted in an expansion in the CF continuum to incorporate CBAVD, with the caveat that expansion to include other diseases has not been possible. Caveat notwithstanding, I would argue that this over-emphasises the extent to which the understanding of CF and its relationships with other conditions has changed because of the molecular era, and underemphasises the considerable diversity of descriptions and explanations for CF in the past and the present. I elaborate my concerns below.

Hedgecoe's principal argument is that geneticization has resulted in the expansion of CF to incorporate CBAVD. However, he has not conducted a systematic analysis of the literature to be in a position to make such a claim. The relationship between CF and male infertility is an important part of the CF story in the 1990s, as I have already demonstrated in my 2000 paper, but this is not the simple story of on-going expansion that Hedgecoe spends so much of his paper emphasising. Although he recognises some uncertainty, Hedgecoe does not stress the significance of the fact that many CF workers now describe CBAVD as ‘CF-related’ rather than a ‘genital form of CF’ (a definition from the 1990s). In the words of a leading scientist in the field:

The thought now, is that [CF and CBAVD] are separate entities, in that when manifestations become evident [in men with CBAVD], [when] it looks like CF, then they should be included under the CF diagnosis. When they don’t have manifestations, even if they have the mutations, you can’t really call it CF yet. So it harps back to a clinical diagnosis (Interview with Gary Cutting 2001).

The Online Mendelian Inheritance in Man website reflects this move away from conceptualising CBAVD as a mild form of CF when it summarises the contemporary thinking that at least one form of CBAVD is caused by a mutation in the cystic fibrosis transmembrane conductance regulator gene (CFTR),2 as does the WHO report (2000) that Hedgecoe briefly mentions in his conclusion. This development, well within the period when Hedgecoe was writing his article (but after the period during which my article was prepared), fundamentally undermines his focus upon the expansion of the CF classificatory system.

Hedgecoe also misrepresents the role of uncertainty in the story of CF. Although he acknowledges that ‘at least some clinicians are not happy with the current classification system(s)’ (2003: 63), and he ends his paper by reflecting on the complexity of CF, he places too much emphasis upon the solidification, entrenchment and settling down of the CF continuum in the molecular period. His discussion of uncertainty is brief and towards the end of the paper. In a section entitled ‘Resolving uncertainty’ he suggests that uncertainty is a minor theme because ‘there is only so much ambiguity a classification system can take before people want to sit down formally and agree on what to call things and where to put things in relation to each other’ (2003: 62). He implies that uncertainty about the CF classification system is the by-product of geneticization, and he seems to represent uncertainty as being a consequence of the continuum's expansion.

In my version of the clinical continuum between CF and CBVAD, I suggested that uncertainty was integral to the process of establishing the continuum. This is different from saying that it is something to be resolved. Three years later, I want to stress that uncertainty can also undermine these types of continua. This would seem to be especially true in the current clinical context, when further genetic tests to diagnose CF in men with CBAVD and no other symptoms of CF are rejected by some CF clinicians, infertility specialists and the men themselves.

More generally, I would argue that uncertainty about the boundaries of CF is central to its history3. For example, CF workers have long considered the links between CF and asthma (Caplin and Haynes 1973, Cox and Talamo 1979, Strauss and Mendes 1978, Barnes 1996, Dahl et al. 1998) or sinusitis (Taniewski et al. 1963, Isaacson and Yanagisawa 1998). Even the genetic basis of CF involves considerable uncertainty, in the past and the present. For example, the work on cell cultures and serum in the 1960s and 1970s led many to argue that CF was not one entity but a group of related disorders (e.g.Brimblecombe and Chamberlain 1973). This uncertainty is also reflected in contemporary discussions about the role of so-called ‘modifier genes’, where it is argued that the clinical variation in CF involves more than one gene (e.g.Drumm 2001). As Hedgecoe briefly acknowledges, molecular genetics does not necessarily increase the certainty of a CF diagnosis; it may even make it more difficult. However, his claim that ‘Classification systems which rely on linking CFTR mutations to CF obviously face a few problems’ (2003: 62, my emphasis) is a misrepresention of both the form and function of uncertainty in this area.

In sum, Hedgecoe presents a rather inflexible, and a-historical picture of CF. In my 2000 paper, I stressed the dynamic nature of the CF continuum and the elasticity of established genetic categories. I argued that ambivalence was fundamental to the continuum and that, ‘without this type of uncertainty, concepts and explanations would lose their flexibility and the continuum would ossify’ (Kerr 2000: 869). Hedgecoe presents such an ossified continuum when he removes or brackets much of the contingency and diversity that is characteristic of this field of research and clinical practice. This is partly due to the very small slice of literature on which he has drawn. His analytical focus upon ‘geneticization’ also means that he foregrounds genetic reductionism at the expense of ambiguity and uncertainty, and, ultimately, overstates the impact of molecular knowledge on the definition and diagnosis of disease.

My concern is that this kind of approach fuels the ‘hype’ around molecular genetics and does not reflect the perspectives of many of the scientists and clinicians working in the CF field. These problems with Hedgecoe's paper lead me to conclude that the notion of geneticization has limited value when applied to the social construction of genetic disease. To understand how molecular genetics has shaped the definition and diagnosis of disease, we need to engage more fully with the multiple representations of genetic diseases in the past and the present.

  • 1

     Funded by the Wellcome Trust's History of Medicine Programme, 1997–2002, Grant number 050491

  • 2
  • 3

     I am preparing a paper on this topic, entitled ‘Disease and diagnosis: a history of cystic fibrosis’, to be submitted to Social Studies in Science in the near future.


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