Today is Rare Disease Day - a day that acknowledges over 7,000 rare diseases people around the world suffer from. In the United States a rare disease is defined as affecting under 200,000 citizens of the US. When a disease affects only a small portion of the population it may be more difficult to diagnose, often leads to diagnosis later in life and may mean that treatment is delayed or less effective. Often people with these diseases feel isolated as there is little information or support for them. Rare Disease Day has been declared to raise awareness to small populations dealing with a variety of diseases ranging from metabolic disease, rare cancers, genetic issues, etc.
Our family has dealt with rare disease on a personal level. Zachery, our 20 year old son, has Primary Hyperoxaluria III which was diagnosed this summer, but which we have been dealing with since he was nine years old. PH III, as it is known, was only discovered in 2010 and appears to affect about 1 person/million.
When Zach was nine years old, he passed a calcium oxalate kidney stone, very unusual for a nine year old, but not unheard of. Because Zach was so healthy we carried on as usual until he passed another kidney stone at the age of 13. Not fun for anyone, let alone a 13 year old. At this point the Urologist we were seeing referred us to a Nephrologist at the Calgary Children's Hospital. Through testing, they found that Zach had very high urinary oxalate levels. That was the moment we recognized there was a problem. Before Zach passed these kidney stones we had never even heard of oxalate and likely many of you haven’t either.
A quick explanation of oxalate and hyperoxaluria here from the Oxalosis and Hyperoxaluria Foundation here:
Oxalate is the salt form of oxalic acid, and is a natural end product of metabolism. Oxalate does not appear to be needed for any human body process and normally, more than 90% is excreted by the healthy kidney, with a small amount of excretion into the lower gut. Since oxalate and calcium are continuously excreted by the kidney into the urine, it can combine with calcium causing formations of calcium-oxalate crystals and grow into a kidney stone...
Hyperoxaluria is uncommon. In some people the cause of the excess urine oxalate is not known but may result from changes in the way kidneys handle normal amounts of body oxalate. In its many forms it can be found among all ages, from infants to people in their 70's. The highest amounts of oxalate in the urine however are seen in diseases in which the liver produces too much oxalate - this occurs in primary hyperoxaluria.
Because of the low solubility of oxalate, increased concentrations of oxalate in body fluids, including the urine, can lead to the deposition of calcium oxalate (oxalosis) in the kidney tissue (nephrocalcinosis) or urinary tract (urolithiasis, nephrolithiasis, kidney stones). Oxalosis occurs after the kidneys fail and the excess oxalate builds up in the blood and then deposits oxalate salts in the eyes, blood vessels, bones, muscles, heart and other major organs.
WOW! We were stunned, our otherwise healthy son was at risk of kidney failure, but we still did not have a diagnosis. I cannot tell you the range of emotions we went through.
The Nephrologist put Zach on a low oxalate diet as oxalate is found in some foods in higher amounts; spinach, rhubarb, whole grains etc. We found that the low oxalate diet did not affect Zach’s oxalate levels. In fact, his oxalate increased on the diet. I went into research mode immediately. I found kidney stones are rarely found in primitive societies – which meant there could be a correlation between processed foods and kidney stones (beside salt content). We started playing with Zach’s diet and found that by eliminating complex carbohydrates (all grains, no sugar and disaccharides) we could keep his oxalate levels within normal parameters on a consistent basis. The doctors noted this and we went to the GI clinic at the Children’s Hospital, thinking there may be a gastro-intestinal issue. Zach was tested for Cystic Fibrosis among other GI issues, but nothing was found. He was also tested for Primary Hyperoxaluria I – negative. Still no diagnosis.
While Zach was in his teens and living at home, he was a great sport and followed the grueling diet to a letter, keeping his oxalate low. Then he went off to college and started eating like everyone else (very hard to eat a salad when your friends are eating pizza and drinking beer). He had another urinary oxalate test and we found his oxalate levels were again very elevated.
I, again, went into research mode wanting some kind of answer as to just what we were dealing with. I turned to the internet again, a doctor’s nightmare, I know! This time I found the Mayo Clinic in Minnesota was researching hyperoxaluria in a big way. I contacted Mayo Clinic and they were amazing. Because there are so few people with Primary Hyperoxaluria they wanted to genetically test Zach for the disorder. Through mail, we sent back blood samples and waited. Our answer came this summer – Zach has Primary Hyperoxaluria III.
Primary Hyperoxaluria is a rare autosomal recessive genetic disorder passed on by both my husband and myself to Zach and our daughter is also a carrier. Again, who knew?
We have since visited the Mayo Clinic where Zach took part in a research study to try and pinpoint the cause of Primary Hyperoxaluria III. Little is known about its cause.
What does Zach’s diagnosis mean? Well, for starters, there are no known PH III patients who have lost kidney function to date, but there are very few diagnosed cases of PH III. Secondly, we have found that drinking more than 3-4 liters of water daily lowers Zach’s risk of kidney stones and kidney damage immensely. This is a disease which is still being studied by doctors who are devoting themselves to a small population and we are extremely thankful to them.
Zach’s is an ongoing journey through a little known disease, of which ironically, little is known. We feel fortunate that Zach’s prognosis appears positive, there are others who are not as fortunate. Rare Disease Day is a day of hope for those who are affected by rare diseases and the medical community which is working with those afflicted.
We are very thankful!