Why, after attending the first full day of the International Society for Prenatal Diagnosis in Miami, Florida in 2012, was I drinking from a fifth of Wild Turkey on the beach long after the sun had gone down? Read on to find out.
Careful readers will note that the last installment of the book I’m serially publishing on this blog about Down syndrome and prenatal testing was numbered out of sequence. The immediately preceding post was titled “Chapter 2, Part 4,” but the last post was titled “Chapter 2, Part 6.” This is because, after examining prenatal diagnostic testing, I had leapt right into addressing prenatal genetic screening. Upon reflection, however, I thought there needed to be a new section on “screening” generally.
Except, I had not already written a section on screening generally. Hence the three month interlude between the last section of the book and this one. No, what you’re about to read didn’t take me three months to write. Well, in a sense it did: it took three months of procrastination to finally getting around to writing this section.
As I stated when I started this series of posts, part of the point of it is to force some discipline on my writing. While this screening section took three months of procrastination, when/if we get to Chapter 5, that has yet to be written, despite Chapter 4 being close to being finished over two years ago. So, in that regard, this serial publishing is helping to keep me on track. If you would like to further help with that, the more you comment, share, or ask when the next post is coming, that, too will motivate me.
With that said, here’s Part 5 of Chapter 2:
The 2012 ISPD Conference
In 2012, I flew to Miami, Florida for the annual conference for the International Society for Prenatal Diagnosis (ISPD). By this point, I had attended a couple of ACOG conferences and some of the conferences for ACMG and NSGC, but this was the first time attending ISPD’s.
As the name of the organization suggests, it is the sole organization focused on just prenatal testing and it is a worldwide organization. I’ll share in later sections on cell free DNA the interesting breakout session from this conference, held just months before Sequenom went to market with MaterniT21. But, at this point, the initial plenary session I attended is where I learned about the historical framework for public screening programs.
Wilson & Jungner Principles of Screening
At these medical conferences, I am very much a fish out of water. Doctors have a somewhat justified disdain for my profession. Either we’re the in-house counsel of a hospital system citing some regulation to deny their proposed innovative surgery, or we’re suing them for an allegedly botched procedure.
But, the plenary appealed to me because it was set up as a debate over whether there should be routine screening for Fragile X syndrome. There was a presenter who argued in favor of widespread Fragile X screening and a presenter who argued against it.
Both agreed to a common set of principles to guide the examination of the issue. Well, more than “agreed”, both cited the same framework that is historically cited for determining whether a condition should be part of a public health screening program.
The cited authority was from a publication of the World Health Organization in 1968: Wilson & Jungner’s Principles and Practice of Screening for Disease. The principles outlined in this massive work are:
- The condition sought should be an important health problem.
- There should be an accepted treatment for patients with recognized disease.
- Facilities for diagnosis and treatment should be available.
- There should be a recognizable latent or early symptomatic stage.
- There should be a suitable test or examination.
- The test should be acceptable to the population.
- The natural history of the condition, including development from latent to declared disease, should be adequately understood.
- There should be an agreed policy on whom to treat as patients.
- The cost of case-finding (including diagnosis and treatment of patients diagnosed) should be economically balanced in relation to possible expenditure on medical care as a whole.
- Case-finding should be a continuing process and not a “once and for all” project.
These were the principles by which the debaters structured their pro and con arguments.
Screening for Fragile X
Despite having written, researched, and presented on prenatal testing for Down syndrome for years by the time of the ISPD conference, I had never considered the a priori position of what justified prenatal testing for it in the first place. Having been done regularly since the 1980’s, I instead focused on what the recommendations were for how it was to be done. The ISPD plenary provided an opportunity to time travel to before prenatal testing for Down syndrome was taken just as a given.
The presenter arguing in favor of widespread Fragile X screening emphasized the first, fourth, and seventh principle of it being an important health problem that was well understood. Fragile X is associated with intellectual disability, particularly in males, since we only have the single X chromosome whereas women, having two X chromosomes, can compensate in some cases, and, being gene-based, it’s detectable prenatally.
The presenter arguing against widespread screening had a two-prong attack. The screening test, at that time, was not that accurate, and therefore did not satisfy the fifth principle. Moreover, contra the sixth and eighth principles, Fragile X is oftentimes latent in females, making them carriers. Therefore, whom to treat as patients posed a challenge, since testing the expectant mother also had relevance for any sisters or daughters of her, as they, too, may be carriers.
Of concern, at least to me, was how both did not just skip over the second principle, but how they both acknowledged there was no treatment for Fragile X syndrome if detected.
The presenter arguing against widespread screening could have began and ended by simply noting genetic screening does not satisfy the Wilson & Jungner principles because there is no treatment for genetic conditions detected prenatally. Had it been a contest in moot court or a debate team, the arguments would have been over and the presenter arguing against screening would have been declared the winner.
But, this was the International Society for Prenatal Diagnosis. An entire, worldwide organization devoted to prenatal testing. ISPD had long ago breezed past the fundamental flaw in prenatal genetic testing: that there is no treatment available for the tested-for conditions.
Beach and bourbon
With the passage of time, I can’t say for certain whether the presenter arguing in favor of Fragile X screening harped on the ninth element, commonly referred to in shorthand as “cost-effectiveness.” I want to say the presenter did have some study showing how the costs of screening for Fragile X were outweighed by the amount of health dollars saved by the number of children “avoided” or “prevented” from being born by prenatal genetic testing.
I can’t say for certain whether that was part of the argument because the presentations made throughout the day that I attended had enough other speakers making that claim in support of further expanded prenatal genetic testing.
In session after session, someone would mount the dais and talk of a new economic study or an attendee would make the point in Q&A. The studies or the speaker would claim prenatal genetic testing for Down syndrome, or another condition, was cost-effective. By this, they meant–and said–the number of potential lives that could be detected, and then prevented, would thereby “save” millions of dollars. Those dollars being for the public support programs that otherwise would be expended on these lives if they were born, rendering them “burdens” to the health system.
To be fair, at the end of the debate in the plenary session the audience was asked to vote by raising their hands on which side had persuaded them. Prior to the presenters making their respective cases, the audience was closely split 50/50 on whether they would support widespread Fragile X screening. After the arguments, the opponent of screening for Fragile X had won over a majority of the crowd by a comfortable margin.
But, this outcome was not enough to offset the psychic pummeling I had gone through of hearing doctors, who are to “first do no harm,” argue for why the medical community should use the screening test the private lab they were associated with because of the number of pregnancies that could be aborted resulting in a net savings to the health system–Wilson & Jungner’s 2nd principle be damned.
So, I finished that first day on the beach taking draws off of a fifth of Wild Turkey 101, letting its numbing power wash over me as the waves crashed into shore.
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