Category Archives: Research

Can Pyloric Stenosis come with long-term effects?

Ask your General Practice doctor or a pediatric surgeon about the long-term effects of infant pyloric stenosis (“PS”) and you will almost certainly be told there are none.

However, the volume of questions, complaints, and feedback to online social forum sites such as BabyCenter/Centre, Facebook, MedHelp, Patient, and Topix is a clear sign that the answer to this question is not quite as clear and simple!

The issue of possible long-term gastro-intestinal (“GI”) and other complaints after PS is in fact a complex subject.  The social forum interest mentioned above shows that there is a short list of long-term effects that those affected suspect may not be unrelated to having had infant PS and/or the surgery to remedy it.

However, many of these complaints are hard for medical science to study and possibly recognise, and therefore for your doctor to treat.  So unfortunately for us, many busy doctors will brush off patients’ attempt at consultation about them as a waste of their time; others will recognise the problem but can usually offer little more than sympathy!

Besides this, GI problems in general (apart from PS) are the most common complaint we take to the doctor, so unravelling their cause and getting effective treatment is a painstaking business! In fact, a small but significant percentage of GI complaints have no verifiable cause at all – and even have a name: “Functional Abdominal Pain Syndrome”.

So… what is beyond doubt?

All surgery (even today) comes with short and long-term hazards, which are acceptable if a life is at stake.  These hazards have been minimised and some virtually eliminated in recent decades – but several remain.  The list of possible immediate and short-term hazards includes anesthetic complications, an unsuccessful procedure (so repeat surgery), wound disruption, and infection.

Those that can arise in the long(er) term include surgical adhesions, collateral damage (usually to the duodenum, stomach or vagus nerve), and emotional issues ranging from scar shame and emetophobia to pre-verbal trauma or mild PTSD.

If the baby has been significantly starved for any reason (usually poor and delayed diagnosis) there may be lifelong effects on several areas of brain function.  Emotional damage can also result from (as happened quite often in the past) the baby’s surgery being done with inadequate pain control, accompanied by significant maternal separation, or by the parents’ trauma resulting from the PS and surgery in any way being conveyed to the infant or to the growing child.

Then there is a short list of GI issues, which are common (also) among people without PS and PS surgery in their early history.  However, these problems seem to be experienced more often by survivors, and are acknowledged as possibly linked by some medical professionals and by several (mostly small) studies.  The theory that high gastrin levels (a blood hormone that controls gastric acid release in the stomach) causes PS in babies is one of the most obvious and plausible among the causes / etiology of IHPS, and this theory links strongly to GI problems in later life. It would also explain why GI problems can arise directly from the subject’s history of PS (the condition), and not the surgery.

The list of long-term GI complaints common among PS survivors includes reflux (or GERD or heartburn), several other GI development faults of infancy, high acidity causing IBS, and sometimes gastric dumping, ulcers and cancer.

There have been more than a few small studies reporting all this, and a few social forum reports of medical professionals who recognise the linkage from their own research and experience.

It may come as a surprise that so little is known (or recognised) about the possible long-term medical issues after PS.  It is because PS is so easily and usually successfully dealt with, and I suspect because the long-term problems are not life-threatening, that there have been no large studies of this subject area.  Besides, there are many more pressing medical challenges that need research time and funds.

The only large study that has stood out showed that the risk of PS is very much raised by mother or newborn using any of the macrolide family of antibiotics – which also relates to gastrin levels!

Despite all this, there has been at least one recent attempt to set up a sizable and robust study of the subject – which the PS community awaits with great interest!

In the meantime it must be realised that the medical community continues to submit to the surgeons’ love affair with PS and repeat the med school mantra that there are no long-term issues to keep in mind in relation to PS.

You can find all the above information on the web. If you need or want my evidence of the above, you’re invited to message me with your email address. I have a list of some 1700 reports and other material which can be accessed via the web.

“No brain, no pain”? That’s insane!

Can a baby remember trauma experienced in her or his first years?

In times past the answer was an insistent “No”.  Before about 1990 it was commonly believed that because virtually nobody can recall and describe any event from early childhood, be it happy or troubling, a baby makes and keeps no record of anything before what we can later recall and express in words.

This of course sounded very reassuring and comforting!

  • The serious mistakes some parents make when a baby is very young – no memory, no record, no damage.
  • Family, life and health dramas which a little one survives – no need to worry about it affecting baby.
  • Separation from mother, adoption, foster relationships – none of this will harm a little one.
  • Will we have our baby son circumcised “so he looks like his dad”?  “Go ahead, no worries!”
  • My baby needs life-saving surgery but anesthetising a baby is risky – “Just go ahead, she won’t really suffer.”
  • A baby’s screams under the knife upset a young theatre nurse – “Hey, he won’t remember anything.”

Evidence contrary to these soothing assurances must have been as clear and widespread as it is today.  If you dare, just check out one of the YouTube videos on what happens when an infant boy is circumcised without pain control.  Still more amazing to us today is that it was believed by many until recently that babies not only don’t remember pain – they don’t feel it!

Besides this, hospitals until recently were “holy places”, the word “holy” meaning “separated, inaccessible”.  Children under 12 were not allowed to visit, a husband couldn’t support his wife in labour, and the fear of infection meant many patients (even babies) were not visited (or touched) while in hospital.

arrogant doc4The health and medical community was fed these “no brain, no pain” mantras in class and then recited them with the absolute authority and firmness that came with their position, especially in earlier times.  Parents and patients would rarely question a doctor’s word.  Doubts, even those arising from observing the painfully obvious, were dismissed.  And doctors were only challenged by “difficult people”.

This situation was of course possible only in the simpler, more authoritarian, and much less informed times which today’s older generations remember well – but only Gen-X’ers and their seniors!

We must remember that there were few alternatives.  Pediatric medicine as a specialist field was not born until 1950, and even after that time anesthetics and pain control were often “basic” compared with today.  All anesthetics (even today) carry risk, and rendering a child under age 3 unconscious involves some additional and substantial risk factors.  In the past a baby’s surgery and pain relief were usually managed by people who did most of their work on older children and adults, so it is not surprising that general anesthesia was often avoided and that the surgery done with enough skill but often little finesse.

So the “no brain, no pain” mantras of past medical science not only suited the times but also served to help parents to cope better with a lot of the all-too-common dramas of family life, including infant surgery.

These beliefs also fitted well with another feature of those earlier times which many of the older generation may remember but still resent:

  • most parents had little or no understanding of their child’s or their own psychology;
  • children were “to be seen but not heard” and were too often “stonewalled” –“Just go and play!”
  • many parents were reticent to talk about uncomfortable things like inner feelings, painful experiences, and uncomfortable subjects.

Baby unhappy01In 1945 I had an operation when 10 days old to control pyloric stenosis, and the details of that were always kept from me. In other posts I have written about how the sad but understandable ways of the past have affected me and many others who had earlier infant surgery.  They did so in a variety of ways –

  • some were affected and/or traumatised as babies by the relative ignorance, inadequacies and failings of medical science and the hospital regime;
  • others were affected by the mantras I have discussed;
  • others again were disturbed by their parents’ inability to help them understand their story and inner being.

People like the “heroes” I have mentioned or discussed in several of the previous posts have been crucial and foundational in challenging some of the medical world’s beliefs and attitudes of the past.  They have researched the old shibboleths and shown them to be utterly wrong.  They have explained how trauma and pre-verbal memories can affect even tiny babies.  They have worked on effective therapies to manage the damage and bring healing and wholeness.

I am so thankful for these people’s skill, insight, courage and determination.  They have changed many lives very much for the better – including mine.

Growing our understanding of pyloric stenosis

If you look up information about infant pyloric stenosis (PS) on the web or in a book, you may well come across the word “idiopathic”, meaning that PS “arises spontaneously or from an obscure or unknown cause”.

Sadly, this is medical jargon being used to cover up the facts that despite –
knowing since 1717 that babies have died of PS or gone to surgery for it,
– PS being the most frequent reason for infant surgery, and
– PS affecting between one and five (or even more) babies and their families in every 1,000 births
we haven’t yet done enough research to agree on what causes PS and how we can reduce its incidence.  Using a “big word” (idiopathic) may also be a convenient way of saving words and time to explain what we do know about PS.

breastfeeding1There is on the web a recently published medical journal editorial article with the title Beyond the Firstborn Son that argues that PS is not “idiopathic” at all.  Sadly, this editorial and the major report on a PS research project are two of countless valuable articles that lay people like me and most of our interested readers cannot afford to access: only the first page of the editorial and a brief abstract of the major report are freely available, but even these I recommend as “good reads”.

The editorial article’s subtitle also uses medical language which is worth working out: Epidemiology to enlighten the Parthenogenesis of Hypertrophic Pyloric Stenosis means: studying the incidence, distribution, and possible control of PS can help us to understand its causes.

The 21 October 2013 issue of this medical Journal features the major study by a Seattle team to which I referred in a previous post.  It studied 714 confirmed PS babies over 7 years (2003 – 09) to map what they had in common and compared these results with a 10 times larger control group: a very large project.

Among the discoveries made or confirmed –
– the incidence of PS declined during these 7 years from 1.4 to 0.9 per thousand births;
– during these years breastfeeding increased from 80% to 94%;
– compared with the controls, PS babies were more likely to be bottle feeding after birth (19.5% vs 9.1%),
– any duration or proportion of bottle feeding affected the risk factor,
– smoking (identified as a risk factor in previous work) was found to increase the risk of PS 1.5 fold,
– firstborns (and thus younger mothers) run a 1.8 fold higher risk, and
– older mothers’ risk of having a PS infant is halved.

Bottle feeding1These and other comparisons led the team to conclude that especially bottle feeding is associated with an increased risk of HPS, and that this effect seems to be strongest in older women and mothers of more than one child.  It was also found that although smoking increases the risk of a baby having PS it did not change the risk factor of the way the baby was fed.

This study and the large Danish study published in 2012 came to much the same conclusions.  They are also examples of the fact that discovering the causes of many medical conditions will likely be a slow and laborious process akin to assembling a huge jigsaw puzzle!

What can we conclude from the Danish and US studies showing the value of breastfeeding in lowering the risk of a baby having PS?

Mother and baby31                    It shows the way for more studies.  We know that PS is multi-factorial and the more we know about each risk factor, the better we can research whether and how these interact.  The findings about bottle feeding and smoking mentioned above are an example of this.

2                    The Seattle study confirmed previous findings that PS has been a Caucasian malady by a considerable margin, and that older mothers do not have a higher chance of having a PS baby (despite earlier studies coming to the opposite conclusion).

3                    The editorial points out that studies between 1975 and 1983 noted a rising rate of breastfeeding and incidence of PS and drew link between the two.  This new and large study has given significant reason to reject the earlier correlation.

4                    It is noted in the editorial that “bottle feeding” is difficult to define for the purposes of research.  I have mentioned the matter of the duration and proportion of bottle feeding.  The formula is another variable which could play a significant role in the acidity that is a key factor in the development of PS, as Dr Ian Rogers has shown (as reported in several posts).

5                    It does seem possible to conclude that the feeding mode of the first 6 months is more influential than the age of the mother, smoking, and how many children she has had.

6                    The editorial states: For a disease as common as pyloric stenosis, it is of benefit to have precise estimates of the common risk factors.  I might add that all the risk factors identified and quantified in these two studies are worthy of parents’ consideration.  However, other risk factors such as genetics or inheritance cannot be reduced by us – although I have come across at least two couples who knowingly grew their risk profile: both partners had a PS history – and of course had PS children.

It must be clear that although these two studies on the relationship between how an infant is fed and its chance of developing PS only deal with a small number of risk factors and issues around PS and infant surgery.  They are nevertheless significant to us all in several ways, and especially to new parents, to the pediatric medical community, and to those like me who would like to understand PS better and work to see its incidence fall.

Infant pyloric stenosis and some research findings

There are some good reasons to complain about the scarcity of research into the causes of infant pyloric stenosis (PS).

For one, more could be done to reduce the risk of PS developing if we knew more about its many suspected non-genetic triggers.

And with more interest and knowledge about the effectiveness of alternative treatments there might be much less surgery which would be welcomed by both parents and (later) by the patient.  I have written about this in a recent post.

But the past two months have seen two valuable research reports published.  During the past month Google’s search results (even for a 24 hour publication limit) for references to “pyloric stenosis” have spilled over numerous screen pages at 10 entries per page.  Clearly, the media, medical journals and health magazines ARE interested in good news about PS.  And so am I.

What is the good news about PS?

Genetics03A Danish study published in August 2013 discovered an identical genetic link with PS and with the mother’s low blood cholesterol level.  In the Abstract which is available to us I have not read that maternal low cholesterol actually causes PS, only that there is a genetic correlation between the occurrence of the two.  The research has found that certain genes are linked to both lower cholesterol levels and infant PS.  It also found that babies with lower cholesterol levels developed PS more often than average.  More work will hopefully clarify the relationship; perhaps there is a cause and effect there somewhere?

At the very least, this discovery should alert and encourage at-risk parents to be watchful and press more vigorously for the early testing and diagnosis of any sign of PS symptoms in their newborn.  PS that occurs after the first 2 – 3 weeks can usually be treated very effectively by medical drug therapy – although sadly, finding a doctor and hospital equipped and willing for this course of treatment may be a somewhat greater challenge than overcoming the PS!

Bottle feeding1Another large study, from a Seattle USA team and published this week confirmed and extended another recent Danish research team’s finding that breast-fed babies are at less risk of having PS than bottle-fed babies.  While most of the Google-prompted articles I read simply use the material provided by the Abstract of the academic report, I discovered that the US Las Vegas Guardian Express found Dheepa Balasubramanian able to pass on not only the report but to explain its background and significance, as well as related matters – and he does that in a way that quite agrees with Dr Ian M Rogers’ work which has been so helpful to this blog.  I won’t copy and paste the key lines of this article, as for those interested it is worth clicking the link to read it in full.

This second report is even more and more immediately and practically valuable to parents than the first, as Dheepa Balasubremanian’s explanation makes very clear.  I am sure that parents who have experienced something of the trauma of PS will use these findings to reduce the risk of their children developing PS, and if they do have it, to increase the likelihood of their baby being able to avoid a meeting with the surgeon.

Scarce and conflicting research on pyloric stenosis

Trigger 1
Recently I had my 2-yearly “full medical” exam (and passed it well), but something my doctor said struck me.  When I asked him why he wasn’t running a particular test as in the past, he said that recent reports about that test’s value were so conflicting that he thought it better to rely on other indicators.  Fair enough.

Trigger 2
Mothers-to-be in Melbourne (Australia) are going to be invited to participate in a promising medical trial, our morning radio told us today.  There are indications that immunizing newly-borns with BCG vaccine against tuberculosis may reduce the fast growing occurrence of childhood allergies (very common in Australia), and this trial hopes to confirm this finding.  The question was asked, if early indications have been so promising and the vaccine is widely used in many countries, why not make the trial much larger?  The answer: funding is only available for a few thousand participating.

Trigger 3
I recently interacted with a PS survivor who challenged me about my belief that PS occurred more often in premature than full-term babies.  I consulted several reports in my collection and admitted she was correct.  Since then, almost everything I have read about this issue confirms my original understanding.

This blog exists because as one who had surgery at 10 days old for pyloric stenosis (“PS”), I know the value of sharing much more information about this condition: how it behaves, how to treat it, and the long-term effects of both the condition and its surgical remedy.  For most PS survivors, their story seems to be little more than a blip, or an unusual scar on their body.  But for some, their PS page has been a mystery, even a closed secret, the scar a significant embarrassment in their growing up, and the surgery has left them with physical and emotional wash-up they find hard to discuss and understand.

In this post I want to link the above three “triggers” with what we know and don’t know about PS.

Sparse research

It is frustrating that although PS has been recognized for some 300 years and surgically treated for a century, it is still rather imperfectly understood.

This is because there are far more medical conditions and challenges than research funds.

Question-marks1Research funds and projects will inevitably concentrate on the issues that affect the lives and income of the great majority of the people in the developed world.  Heart disease today is much better understood, reduced and treated and early death related to it far less likely because of the present armoury of drugs, reduction strategies and surgical technology.  The same can be said about cancer, diabetes, blood pressure, kidney disease, bone and skeletal degeneration, pregnancy and childbirth, and even the brain.  And despite the mentally ill being the human family’s poor cousins, psychiatry has seen similar advances in helping those with mental illnesses to stay in society and even work.  Anesthesia and pain control have also seen remarkable progress.  I could continue…

It seems to me that the less common and the most inevitable and age-related conditions have missed out most on progress: congenital conditions, many of the rarer cancers (e.g. in the pancreas), and age-related illnesses such as dementia, multiple sclerosis and similar degenerative diseases.

Sadly, the malformations and conditions of early life are also in that category.  PS is the most common condition of infancy to be treated with surgery, and there are many more, most of them more severe.  But very little progress has been made in learning how these can be avoided or the risk of their development reduced.

The reason is ultimately money.  The cost of modern medicine is increasing far beyond our income and the other costs of living, including the costs of clean water and usually dirty energy.  Few governments dare to devote more of their budget to medical research. Corporate charity is usually extended to those who can unlock new income.

Conflicting data

Sadly, not only are funds more medical research very scarce, but if PS-related research is any indication, many of the results of the little research that is done in more off-beat areas shed little useful light.  Here are some of the areas of clear and “statistically proved” disagreement that I have found during many years of reading online research reports on matters related to PS –

  • Q mark1Are breastfed or bottle-fed babies at greater risk of having PS?
  • Are premature or term babies more likely to develop PS?
  • How many Caucasian (“white”) babies in 1,000 are likely to have PS?
  • Is there a link between parent income and work and the incidence of PS?
  • What percentage of PS affected babies are first-born?
  • What percentage of PS babies have an affected relative?
  • Is PS almost impossible to recognise and diagnose promptly and early?
  • Which is the less costly way of treating PS, surgery or medical therapy?
  • Is medical treatment of PS almost impossible for willing parents?
  • How many babies have gastric problems like GERD and IBS after a pyloromyotomy?
  • Does a pyloromyotomy have any long-term effects?

There are numbers of files in my collection reporting on projects and “evidence” that claim to answer each of these questions in opposite and sometimes several ways. Several observations are in order.

  1. Many of the discrepancies reflected by this list are probably the result of small sampling and/or not mentioned variables resulting in poorly based statistics.
  2. The issues chosen for many of the research projects around PS are mainly statistical and often they are hardly significant, as this list bears out.
  3. Only a few of the areas represented here can help in treating PS.
  4. Very little work seems to be done on the causes and reduction of this and other congenital and early conditions, and I fear this is because such research is costly in time and funds and beyond a doctoral student, an individual scientist or most hospital teams.  But they are expected to engage in research, so “medical research” they do.
  5. Very, very little has been done to identify and quantify the possible long-term effects of infant surgery and conditions like infant PS.

Q mark2What this post shows me might incline me and the reader to feel despair.

However, it gives me hope that when I think back over my lifetime of 65+ years I certainly recognize some areas in which infant surgery has made significant progress during my lifetime. Mortality is way down, general anesthesia is almost universal, and scarring is much reduced.

May this progress continue and grow into those many areas of relative confusion and complete neglect which I have pointed out.

Research into infant pyloric stenosis

People who had pyloric stenosis (“PS”) as a baby as well as their parents may well feel motivated to find a medical organisation that is researching this strange condition.

Having had PS very early in my life and struggled with some of the possible after-effects ever since, I have studied the disease for many years and blogged about my discoveries for almost two years.

Readers of my blogs here (as well as comments elsewhere) have asked me several times where they might direct some funds to further medical research into PS – and I believe with considerable justification.

Both parents and patients often have questions about or experiences with PS that cry out for a clear answer or sound advice.  Many of these people report their frustrations on the web: they are all too often fobbed off, spoken to with condescending dismissal or bland non-answers, or with attempted information which they later discovered was incorrect or inadequate, or by kind reassurance which they later found to be ill-founded.

Some of the questions about PS that need more research or are often dealt inadequately are –

What causes this weird condition?

Can PS be avoided if it’s in my family?

How does the genetics of PS work?  If I had PS will my baby?

When PS strikes can surgery be avoided?

How is PS best treated?

Are there after-effects of PS and of surgery on a tiny baby?

How can the risk of after-effects be reduced?

How will the scar affect a pregnancy?

Is there a link between PS and other conditions of infancy or later life?

On the basis of my reading it seems to me that –

1                    Because PS is quite common in the “old world”, has been recognised for well over a century, and has been treated with a rapidly falling death-rate now for a century, we know much, much more about it than 100 or even 50 years ago.

2                    Despite this, it may seem surprising that many of the above questions have not been answered fully or with certainty.  Many are too often met with sheer ignorance, or answered incorrectly or simplistically.

3                    So many of the medical journal articles and reports dealing with PS examine a subject area that has been reported on many times by many teams.  One wonders how many times pediatric surgeons need to be given statistics and pros and cons for the several techniques of PS surgery or told about the pros and cons of imaging as a diagnostic tool.

4                    Only a few attempts have been made to coordinate and compare the results of similar studies to arrive at a more significant set of conclusions.

5                    I have not found even one organisation devoted to research this most common of all the conditions of infancy that require surgery in the first few months of life, or to gathering and coordinating worldwide PS research projects.

6                    However, I have found one website, RightDiagnosis.com, which offers an information exchange on the existence, aims and needs of current research projects dealing with PS (click on this link to have a look).

7                    Some of the people affected by PS as patients or as parents have the motivation and the means to contribute to a well-run medical research organisation.  Such bodies exist for many of the more serious conditions of the heart, lungs or digestive system, but it seems not for PS.  If this is incorrect, please let this blogsite know by a Comment or just email the writer!  We’d love to pass on any good news.

Infant surgery can have complex causes

A family I know has pyloric stenosis (PS) right through the generations, three that I know of.  PS is a badge of their tribe, and that could be quite affirming, even fun.  I can feel quite envious of them: even if they hate their scar and have PTSD (trauma) from their surgery, they learnt very early that they were not freaks but really belong to their talented and energetic clan!  Other PS families tell stories like that on the web, often light-heartedly.

It took me most of my 66 years to get anywhere near that feeling of being OK and belonging.  My parents could never bring themselves to explain my scar and left me feeling exposed, speechless and unusual at an age when that was traumatic in a variety of situations: as a child in the bath, in the school gym, at the beach, on hot days.  It was nearly 30 years before I met others with a similar scar and realised I was not a unique freak and in fact belong to the enormous PS Club.

It’s only recently that I’ve taken to heart that feeling painfully unique in my family is something that happens to lots of people.  Today some medical reports are being published free and online like the one which enabled me to discover why certain defects of infancy occur just once in some families and many times over in others.

For a reader with a PS history who is able to pick up the basics from among a lot of scientific terminology, the article referred to is fascinating to browse-read: it will give you a glimpse of the gene technology that can now increasingly unlock new information about how we are constructed.  I’ll attempt to glean the main facts here…

The term “multifactorial” is often used when conditions of infancy like cerebral palsy, cleft lip and cleft palate, heart defects, PS and other abdominal conditions, and spinal and neural tube defects like spinal bifida.  “Multifactorial” means they are caused by any of a mix of genetic and environmental causes.

Family tree showing those affected by pyloric stenosis

The report cited shows clearly that any of several genes may be involved when a baby has PS or other multifactorial conditions.  The report details a study of PS in an extended family where it was tracked to chromosome 16q24; but the study also found that the genes of 14 other PS-affected families did not link their PS with this chromosome.  It also found that the PS-linked chromosome in multiple PS families seems stronger (about 2 boys to every girl baby) than in isolated cases of PS (4-5 boys to every girl).  So PS may arise from any one (or more) of several chromosomes – which are still being explored.

Again taking PS as an example, put together the fact that just two or three different gene loci (positions on our chromosomes) have been identified so far that can be linked with PS, and add to that any number of “environmental” factors, just some of which were mentioned in my previous post, like the richness and abundance of the milk the baby gets.  Additional “environmental” factors identified as possible triggers of PS include bio-chemical conditions in the baby’s gut too complex to explain further here, the mother’s age and stress level, whether the baby is breast or bottle fed, the family’s socio-economic circumstances, and other birth defects, as PS comes together with other gut, chest and heart defects and conditions like Asperger’s disease far more often than average.

I’ve often wondered why I seemed to be the only one in my family with PS, and why I haven’t passed it on to any of my 13 children and grandchildren (“touch wood”), whilst other families include many with this affliction.  I’ve been annoyed that there seems to be so little research into the causes and prevention of PS and similar conditions that trouble new parents and their babies.  But I’m increasingly realising how complex this branch of science is, and intrigued by the technology that is steadily unlocking some of the mysteries.

Another journal article I read recently defines some terms helpful to understanding the causes of conditions like the ones covered by this post.  The article states: Polygenic traits are determined by the combined effects of many genes.  Multifactorial traits are determined by several genes and environmental factors.  It is now believed that the majority of inherited traits are multifactorial or polygenic.

An associated journal article calls PS a threshold multifactorial trait.  If a woman has PS, she or her parents have abnormal genes or more risk factors (a higher threshold) than is usually necessary to produce PS in males, and her children therefore have a higher risk of the PS recurring.  The affected woman’s male children have the highest risk as they will inherit more than the usual number of susceptibility genes and also because they are the more sensitive sex.

All this means that we can know all there is to know about my gene profile, like my parents have no PS on either side of the family, and still have a child with this condition.  And there are several stories on the web of both parents having had PS and their children not.

Genetics is very humbling and uncertainty is very frustrating for control freaks.  But provided we are sober about our finiteness, the unlocking of more and more of the complex causes of infant surgery is fascinating and reassuring.  The world including our bodies is more intricate than we ever imagined, but our empowerment is making progress, sometimes at a frustratingly slow pace, sometimes with amazing speed, but never complete.