Quick google search says Marfans can be diagnosed with a specialised blood test.
Does the diagnosis change the treatment ? Have you been able to get a referral to a genetic counsellor ? Has the doctor requested genetic testing (did you agree?).
It sounds like you have a lot on your plate. I can emphathise as my three kids also have complex medical/neurodevelopmental differences...
At the end of the day, you know your kids better than anyone and will advocate for them - something I learnt early is that the medical system does not actually advocate for you. They treat specific illness, they don't really plan ahead or look at the broad picture. That's your job as the parent.
There are levels of intervention and care, but there are no 'cures' for the conditions you have mentioned - part of the road is knowing when to get help/intervention, and when to let it be and get on with life...
My kids therapist/psychologist was helpful with this - she said basically if they are on an upward spiral, you are on the right track, and if you are on a downward spiral then it's time to get more support.
The support may also be for you rather than directly for your kid - you are your children's firm foundation...
I can absolutely relate to deep mistrust of doctors/medical system - it's a system, not a single thing - and it's OK to keep fighting on until you get the support...
On the other hand - my daughter has a card that says 'Don't spend so much worrying about your kids being good that you forget you have great kids right in front of you' - as in - positive love and acceptance, and highlighting the positive, goes a very long way.
As a mum of a child with a life-threatening chronic medical condition, I would say that burnout is common and some days/months/years are easier than others. It's our job to deal with the 'what-ifs' and try to keep our kids as happy, healthy and connected to real life as possible.
Have you or your husband been also assessed and processed the fact that you may or may not carry genes for your children's conditions ? - that's where a genetic counsellor can also be helpful - some of our family members struggle with this sense of 'guilt' for passing on faulty genes (one grandparent in particular) and from my point of view it's a really unhealthy and unhelpful discussion - it does not change anything but seems to be a recurring 'tune' that he can't get out of his head...
Wikipedia says 25% of Marfans arises from spontaneous genetics, so that's pretty high - and even if you were carriers, the recommended approach would be to speak to a genetic counsellor if you were planning to have more children, but otherwise, it makes zero difference if you are carriers or not (unless there is some medical check that should be done for your own health)....
Another baseline question is - does it really matter if the specific diagnosis is x or y ? Will it change your child's health or treatment plan ? The two conditions you have mentioned are crossovers anyway (as is Ehlers-Danlos).... and the scoring is so individualised that diagnosis is really a matter of degree of impairment of various systems. And this varies greatly from person to person. It's not really 'one condition' - it impacts each person 'my Marfans is like x, but yours may be like y'....
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5721110/
This article points out the key differential as being "hypertelorism (increased width between eyes), abnormal uvula (wide or with two parts), and cleft palate ....also craniostynosis (skull bones closed too early), clubfoot, joint contractures and cervical spine instability - that sounds quite severe - was your son born with any of these conditions ?
Again, testing will be for one of the known LDS genes.
And the same treatment - monitoring the aorta/heart/blood pressure is needed for both. -- CT - MRI - Echocardiogram.
Also cutaneous features (skin) - poor wound healing, thin, translucent skin with visible veins. - are noted for LDS and EDS, but not MFS.
There is an eye condition - ectopia lentis - which affects MFS but not LDS.
Have his eyes been checked ? It's a serious of tests of the eyes that need to be done.
Basically, you're waiting for genetic testing. If the NZ system is like Australia then you have the option of waiting for it to be done for free (but with a long waiting list) or paying for it to be done privately. Does diagnosis change treatment ? How old is your son ?
I would highly recommend talking to a support/information service that is specific to MFS and getting advice from there about how to speed up diagnosis and ensure appropriate treatment.
https://dermnetnz.org/topics/marfan-syndrome/
This says there is no specific treatment, just regular review to check for any symptoms and life expectancy is similar to rest of population with this regular checking and appropriate treatment if symptoms arise.
MARFANS
Prevalence 1:5000 - 1:10,000 for
1/4 genetics arise spontanously the other 3/4 is inherited
LOEYS
Prevalence: less than 1:100,000
EHLERS DANLOS
Prevalence similar to Marfans.
Based purely on prevalence, first test would be for Marfans, and if that does not come back positive, then they would check for LOEYS and possibly EDS.
I have an interest in childhood conditions and a qualification in medical terminology. If any of the medical terms I've listed or you are finding in the literature don't make sense, then this is where a genetic counsellor can help (can you tell I'm a big fan!) - they will bring out all the diagnostics, statistics and terms, and are trained to then apply them to your situation and help you to understand/decode/comprehend the information and apply it to real life.
Something that doctors often struggle to do
And yes, if it was my child, based on the basics that I found today, I would:
1. Request genetic testing of my child to confirm the proposed diagnosis for Marfans.
2. Contact a support group for marfans in the local area or online, and start to talk to other parents about how to best support my child and family.
3. Request a referral to a genetic counsellor who can explain the condition, implications of diagnosis and benefits/disadvantages of genetic testing.
It is also possible to have very mild marfans symptoms, so in that case it may be suggested for parents to be tested (or at least have their heart checked).... again, I would talk to the genetic counsellor, and possibly your family doctor to see if they recommend testing the parents and other children as well...