No Cure, Only Treatment
Since GSD-I is the result deficient proteins due to genetics, there is no way to cure the patient of GSD-I. Since the genetics of a patient are unable to be altered, the patient will have GSD-I for the rest of their life. Thus, doctors and health professionals can only treat the symptoms of GSD-I, but not the condition itself.
Proper Diet and Supplements
One aspect of treating GSD-I revolves around addressing the metabolite imbalances the patient is suffering from while also promoting growth and development. Due to the fact that glucose is not being synthesized during fasting periods, it has been recommended that the patient eats small, frequent meals of carbohydrates throughout the day instead of a few, big meals (Rake et al., 2002). This will reduce the need for gluconeogenesis pathway being activated and utilized. Since the gluconeogenesis pathway is not being utilized as much, there will not be an accumulation of G6P which is being fluxed in the uric acid, glycerides, and lactate (Rake et al., 2002). It has been well understood that fructose and galactose are to be avoided along with anything high in sugar content (fruits, syrup, honey, candy, etc) (Fernandes, 1974). The addition of calcium, vitamin D and iron supplements may be recommended for GSD-I patients in order to support bone growth, mineralization, and strengthen the immune system of the patient (Minarich, 2012). This strict diet in addition to the supplements has been successfully used in GSD-I patients in order to maintain normal glucose levels, prevent hypoglycemia and maximize growth and development.
In order to address the hyperuricemia and gout a GSD-I patient may encounter, the pharmaceutical drug Allopurinol is often prescribed. Allopurinol (1,5-dihydro-4H-pyrazolo[3,4-d]pyrimidin-4-one) is a 1966 synthesized structural isomer of hypoxanthine which binds and inhibits xanthine oxidase (Kishnani, 2014). Xanthine oxidase is an enzyme involved in converting nucleic acids into uric acid by oxidizing xanthine and hypoxanthine into uric acid (Kishnani, 2014). As a result of inhibiting xanthine oxidase, the production of a uric acid is reduced. Thus, Allopurinol is a drug capable of reducing the level of uric acid in the blood and reduces the possibility of a GSD-I patient suffering from gout-like symptoms.
Liver Surgery and RFA
A problematic area surrounding GSD-I is how to address the complications surrounding the liver. With the accumulation of glycogen in the liver resulting in tumors being generated, it is important to address them immediately. A majority of the tumors produced this way are benign which means they can be surgically removed. GSD-I patients that have malignant tumors require more invasive measures such as surgery or a procedure known as radiofrequency ablation (RFA) (Ahn et al., 2013). Radiofrequency ablation is a procedure where the doctor uses X-Ray guidance (fluoroscopy) with needle electrodes in order to direct electrical current to the tumor site. The electrical currents produce heat which destroys the tumor cells. If RFA and surgery are not viable options, then liver transplantation may be required (Ahn et al., 2013). In order to reduce the risk of liver and kidney tumors being problematic, GSD-I patients are suggested to be monitored annually with liver and kidney ultrasounds and blood work (Koeberl, 2009).
One of the most intriguing treatments available to GSD-I is the use of uncooked cornstarch. Uncooked cornstarch is a continuous nasogastric glucose polymer which is digested slowly and helps maintain blood glucose levels (Bhattacharya et al., 2007). Upon further review of these uncooked cornstarches, although it did help the GSD-I patients, administering it was difficult because many found it unpalatable and resulted in stomach pains and diarrhea. Why seeking an alternative, Bhattacharya et al. synthesized a new uncooked physically modified cornstarch (WMHM20). When comparing the results of uncooked cornstarch and WMHM20, they discovered that not only was administering the cornstarch easier, but WMHM20 resulted in blood glucose concentrations decreasing more slowly and lactate concentrations decreased more rapidly (Bhattacharya, 2007). In addition to this new discovery, Beegle et al. discovered that while administering cornstarch and stabilizing metabolic conditions, livers and liver tumors in GSD-I patients decreased in size up to 10% (Beegle et al., 2015). This finding is incredible because if researcher can begin to investigate and synthesize new cornstarches which will reduce liver and liver tumor size, then invasive techniques such as RFA and surgery will no longer be necessary.