Differential?

[stefaniebillette]

I haven't written in a while because we have still been trying to get a firm diagnosis. Our son developed liver problems in infancy and in order to avoid biopsy and other invasive procedures, we started learning as much as we could about metabolic conditions. I was convinced that he had HFI and put him on a fructose free diet back in December. After 4 months, his liver is starting to heal with his "lesions" shrinking and his spleen no longer at the upper limit of normal size. All his labs are normal now, and he's no longer vomiting or having hypoglycemic episodes. But, the shock came when the HFI testing from Baylor came back normal. We are stunned and confused. I was hoping that some of you in this message board might know if there's any other disorder that mimics HFI. He hasn't been tested for the GSDs and the geneticists are about to send his blood out for exome sequencing, but that takes several months. We're sticking with the diet but are just baffled.

[lucky]

Hi stephaniebillette,

I'm lucky. Nice to meet you.

First and foremost, congrats on your son's improved health. Progress like this is absolutely wonderful

Secondly, if your son's specialists are currently looking into alternatives that can mimic HFI, they may also be considering this:


FBPase deficiency (Fructose 1,6 Bisphosphatase deficency)
hfiinfo.proboards.com/thread/1209/fbpase-deficiency-testing


Please let me know (here or privately in the member's message section) if I can help further.

Best,
lucky

[jejns1]

Hi stephaniebillette,

My daughter also had the genetic test at Baylor. It came back negative. Our doctor said the test
can rule in a diagnosis but cannot rule out HFI, because all of the mutations have not been
identified. FBPase deficiency is another possibility, which is the one I lean towards based on my
kid's symptoms. Their doctor is confident they have HFI in some form or another.

[antonia]

We had the same conversation with our geneticist. Other than FBPase Deficiency there is one form of GSD that can mimic HFI. It involves intolerance to all sugars though, even lactose. So if your son does not tolerate lactose, in addition to fructose, could be a possibility.

Out of curiosity, what is exome sequencing? I've never heard of that before.

[rysmom14]

Great news that your son is doing much better. My son had the exome sequencing done at Baylor and his initial results came back showing nothing ( it took over 7 months to get the results). 4 months after that we got a call from the Genetic Dr saying we needed to come in because his test was run again and they found the mutation known as HFI. I couldn’t understand how they could have missed it the first time around. I agree with what jejns1 said about the test being about to only rule things in, not out.

The way the Dr. explained it to me is that when his blood was sent to the lab, they run numerous panels against other patients samples that would show likely mutations that are based on the symptoms my son presented with. (He had liver enlargement, under functioning liver which caused distended abdomen filled with fluid, vomiting and acid diarrhea.) it seems that they must not have run the panel that would have showed the HFI. So he must have been put into a test group for another person which would have included HFI and that is how he showed up. The more people are diagnosed and have documented symptoms they easier it will be to diagnose in the future.

I recently had my third child who is 3 months old. We had her tested for HFI. We used Baylor lab again, but because we knew the specific mutation they were looking for they were able to check for just this and responding in a couple weeks. ( she does not have HFI. YAY!!)

So all that being said, when they run exome sequencing, it is a broad based test, so they are not looking for a specific mutation or any specific disease. I don’t know how to go about asking them to test specifically for HFI. In my daughters case we knew what we were looking for and that is the only test they ran, but it can be very expensive to individually test for each mutation, so that is why the exome sequencing is a good option.

For the others who were interested in knowing more about what exome sequencing is, I will tell you that it is extremely expensive ($20,000) and very hard to have insurance cover. My son’s was covered while he was an inpatient in the hospital, but the Dr. said that it is very hard to get that level of testing approved and covered, especially as an outpatient. Insurance would not even cover my daughter’s test even though a sibling was already diagnosed.

If they are looking to run more tests I would recommend staying with the HFI diet until you know more. You know that it’s working so it is HFI you are already doing to best thing for him!

[stefaniebillette]

Our local geneticist agrees with us that he must have something like HFI. The hepatologist and geneticist we saw out of state are still entertaining other theories which is why they're doing these broad-based tests. They did a microarray (came back normal) and now they want to do exome sequencing, both of which our insurance would not cover so they sent the DNA to a lab that works with families who cannot afford the testing. Our out of pocket for each was only a couple of hundred dollars. I'm not convinced we're going to get any answers from exome based on my readings. When HFI came back negative, my thought was that he may have a new mutation for HFI which would not show in any of these tests. So, I wonder how they discover new mutations...
We are continuing with the diet since it seems to be working. He eats very little dairy because our family is lactose intolerant. He seems to have some similarities with GSD 1 and GSD 9. Interestingly, as he starts to eat more solids and get trace amounts of fructose (e.g. celery powder in bacon), his ALT and AST have risen a bit.
As you know, it is not an easy diet, but he looks/ acts well that my gut is telling me have the right treatment even without a firm diagnosis.

[hfimomof3]

Did your doctor mention to make sure he is getting enough daily Vitamin C in his diet or from a vitamin? That is an area where people with HFI are at special risk. If he cannot use regular kids' multivitamins (some are very sweet), you should be able to find a vitamin that is just vitamin C. I am not a doctor, this is just what I have been told as a person with HFI.

[Stefanie (Ziba)]

UPDATE:

Our son has had the HFI test, Microarray and Exome. The only revelation is that he is a carrier for GSD 1B. Everyone insists that you cannot have symptoms being a carrier, but there is no doubt he cannot tolerate fructose. He has been fructose-free for 18 months and it has changed his life completely. No more vomiting/diarrhea, improved labs and his ultrasound is stable (bright liver with dark spots).

I would love to have a firm diagnosis, but for now, he gets fructose-free, takes carnitine supplementation (game changer) and Biogaia probiotics (huge help with gas and bloating) and drinks 32 ounces of Abbott Nutrition's Elecare Jr which gives him all vitamins and minerals.

I still get nervous when introducing foods. For example, I have no idea if HFI ppl can tolerate tartrate/tartaric acid or tapioca starch/flour. Always nervous because symptoms may be subtle with these ingredients. I can tell when he acts "crazy" that something did not make him feel good. Hubby thinks I over-analyze. But, my OCD has gotten us this far!! Haha.

[colormist]

Sounds like he has an excellent set of parents that are doing a fantastic job at managing his condition. Keep up the great work, Ziba. It sounds like you're doing fantastic and are very in tune with your child and his reactions to food.

[Stefanie (Ziba)]

Thank you, Colormist. You have been a great source of inspiration and knowledge.

P.S. We just came from a birthday party, and my little man is so content opening his lunchbox and eating his pretzels and dipping them in sour cream while the other kids stuff their faces with blue-icing, cake and ice cream. Makes you wonder who the "ill" ones really are...

[colormist]

I've been dipping pretzels in greek yogurt; I never thought of sour cream!

I am curious if the birthday party or the sugar consumption activates the crazy child mode. Did you notice a difference between the way he acted and the way the other children were acting "post sugar"?

It's SO MUCH sugar. I do not know how normal people's digestive systems can handle that amount of sugar!

[Stefanie (Ziba)]

It always fascinates me how he is so full of energy and out-paces every other kid. People must think I load him up with sugar!!
I notice kids who eat lots of sugar get this burst of energy and quickly crash. My son is constantly energetic. He does take carnitine too, which adds to the energy.
I don't think anyone is meant to consume that much sugar. Hence, the number of kids and adults with diabetes (not to mention cancer cells which love sugar). I hate that you and my son have this disorder, but at the same time, I am not sure that others are the "healthy" ones.

[ukbill]

ziba
I am 61 and seem far fitter and healthier than all my school mates.
So much for 5 portions of Fruit and veg a day for a healthy diet!

[Stefanie (Ziba)]

You give me great hope, UKBill!