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The primary treatment method for fatty-acid metabolism disorders is dietary modification. It is essential that the blood-glucose levels remain at adequate levels to prevent the body from moving fat to the liver for energy. This involves snacking on low-fat, high-carbohydrate nutrients every 2–6 hours. However, some adults and children can sleep for 8–10 hours through the night without snacking.
Carnitor - an L-carnitine supplement that has shown to improve the body's metabolism in individuals with low L-carnitine levels. It is only useful for Specific fatty-acid metabolism disease.
There is no cure for GALT deficiency, in the most severely affected patients, treatment involves a galactose free diet for life. Early identification and implementation of a modified diet greatly improves the outcome for patients. The extent of residual GALT enzyme activity determines the degree of dietary restriction. Patients with higher levels of residual enzyme activity can typically tolerate higher levels of galactose in their diets. As patients get older, dietary restriction is often relaxed. With the increased identification of patients and their improving outcomes, the management of patients with galactosemia in adulthood is still being understood.
After diagnosis, patients are often supplemented with calcium and vitamin D3. Long-term manifestations of the disease including ovarian failure in females, ataxia. and growth delays are not fully understood. Routine monitoring of patients with GALT deficiency includes determining metabolite levels (galactose 1-phosphate in red blood cells and galactitol in urine) to measure the effectiveness of and adherence to dietary therapy, ophthalmologic examination for the detection of cataracts and assessment of speech, with the possibility of speech therapy if developmental verbal dyspraxia is evident.
In terms of treatment for short-chain acyl-CoA dehydrogenase deficiency, some individuals may not need treatment, while others might follow administration of:
- Riboflavin
- Dextrose
- Anticonvulsants
Low-protein food is recommended for this disorder, which requires food products low in particular types of amino acids (e.g., methionine).
No specific cure has been discovered for homocystinuria; however, many people are treated using high doses of vitamin B (also known as pyridoxine). Slightly less than 50% respond to this treatment and need to take supplemental vitamin B for the rest of their lives. Those who do not respond require a Low-sulfur diet (especially monitoring methionine), and most will need treatment with trimethylglycine. A normal dose of folic acid supplement and occasionally adding cysteine to the diet can be helpful, as glutathione is synthesized from cysteine (so adding cysteine can be important to reduce oxidative stress).
Betaine (N,N,N-trimethylglycine) is used to reduce concentrations of homocysteine by promoting the conversion of homocysteine back to methionine, i.e., increasing flux through the re-methylation pathway independent of folate derivatives (which is mainly active in the liver and in the kidneys).The re-formed methionine is then gradually removed by incorporation into body protein. The methionine that is not converted into protein is converted to S-adenosyl-methionine which goes on to form homocysteine again. Betaine is, therefore, only effective if the quantity of methionine to be removed is small. Hence treatment includes both betaine and a diet low in methionine. In classical homocystinuria (CBS, or cystathione beta synthase deficiency), the plasma methionine level usually increases above the normal range of 30 micromoles/L and the concentrations should be monitored as potentially toxic levels (more than 400 micromoles/L) may be reached.
The treatment goal for individuals affected with OTC deficiency is the avoidance of hyperammonemia. This can be accomplished through a strictly controlled low-protein diet, as well as preventative treatment with nitrogen scavenging agents such as sodium benzoate. The goal is to minimize the nitrogen intake while allowing waste nitrogen to be excreted by alternate pathways. Arginine is typically supplemented as well, in an effort to improve the overall function of the urea cycle. If a hyperammonemic episode occurs, the aim of treatment is to reduce the individual's ammonia levels as soon as possible. In extreme cases, this can involve hemodialysis.
Gene therapy had been considered a possibility for curative treatment for OTC deficiency, and clinical trials were taking place at the University of Pennsylvania in the late 1990s. These were halted after the death of Jesse Gelsinger, a young man taking part in a phase I trial using an adenovirus vector. Currently, the only option for curing OTC deficiency is a liver transplant, which restores normal enzyme activity. A 2005 review of 51 patients with OTC deficiency who underwent liver transplant estimated 5-year survival rates of greater than 90%. Severe cases of OTC deficiency are typically evaluated for liver transplant by 6 months of age.
Individuals presenting with Type III galactosemia must consume a lactose- and galactose-restricted diet devoid of dairy products and mucilaginous plants. Dietary restriction is the only current treatment available for GALE deficiency. As glycoprotein and glycolipid metabolism generate endogenous galactose, however, Type III galactosemia may not be resolved solely through dietary restriction.
Management for mitochondrial trifunctional protein deficiency entails the following:
- Avoiding factors that might precipitate condition
- Glucose
- Low fat/high carbohydrate nutrition
Medical Care
- Treatment may be provided on an outpatient basis.
- Cataracts that do not regress or disappear with therapy may require hospitalization for surgical removal.
Surgical Care
- Cataracts may require surgical removal.
Consultations
- Biochemical geneticist
- Nutritionist
- Ophthalmologist
Diet
- Diet is the foundation of therapy. Elimination of lactose and galactose sources suffices for definitive therapy.
Activity
- No restriction is necessary.
(Roth MD, Karl S. 2009)
The goal for treatment of GSD type 0 is to avoid hypoglycemia. This is accomplished by avoiding fasting by eating every 3-4 hours during the day. At night, uncooked corn starch can be given because it is a complex glucose polymer. This will be acted on slowly by pancreatic amylase and glucose will be absorbed over a 6 hour period.
Treatment is possible but unless continued daily, problems may arise. Currently, this is done through supplementation of 5–10 mg of oral biotin a day. If symptoms have begun to show, standard treatments can take care of them, such as hearing aids for poor hearing.
The only treatment for classic galactosemia is eliminating lactose and galactose from the diet. Even with an early diagnosis and a restricted diet, however, some individuals with galactosemia experience long-term complications such as speech difficulties, learning disabilities, neurological impairment (e.g. tremors, etc.), and ovarian failure. Symptoms have not been associated with Duarte galactosemia, and many individuals with Duarte galactosemia do not need to restrict their diet at all. However, research corroborates a previously overlooked theory that Duarte galactosemia may lead to language developmental issues in children with no clinical symptoms. Infants with classic galactosemia cannot be breast-fed due to lactose in human breast milk and are usually fed a soy-based formula.
Galactosemia is sometimes confused with lactose intolerance, but galactosemia is a more serious condition. Lactose intolerant individuals have an acquired or inherited shortage of the enzyme lactase, and experience abdominal pains after ingesting dairy products, but no long-term effects. In contrast, a galactosemic individual who consumes galactose can cause permanent damage to their bodies.
Long term complication of galactosemia includes:
- Speech deficits
- Ataxia
- Dysmetria
- Diminished bone density
- Premature ovarian failure
- Cataract
Treatment for all forms of this condition primarily relies on a low-protein diet, and depending on what variant of the disorder the individual suffers from, various dietary supplements. All variants respond to the levo isomer of carnitine as the improper breakdown of the affected substances results in sufferers developing a carnitine deficiency. The carnitine also assists in the removal of acyl-CoA, buildup of which is common in low-protein diets by converting it into acyl-carnitine which can be excreted in urine. Though not all forms of methylmalonyl acidemia are responsive to cobalamin, cyanocobalamin supplements are often used in first line treatment for this disorder. If the individual proves responsive to both cobalamin and carnitine supplements, then it may be possible for them to ingest substances that include small amounts of the problematic amino acids isoleucine, threonine, methionine, and valine without causing an attack.
A more extreme treatment includes kidney or liver transplant from a donor without the condition. The foreign organs will produce a functional version of the defective enzymes and digest the methylmalonic acid, however all of the disadvantages of organ transplantation are of course applicable in this situation. There is evidence to suggest that the central nervous system may metabolize methylmalonic-CoA in a system isolated from the rest of the body. If this is the case, transplantation may not reverse the neurological effects of methylmalonic acid previous to the transplant or prevent further damage to the brain by continued build up.
Treatment of THB deficiencies consists of THB supplementation (2–20 mg/kg per day) or diet to control blood phenylalanine concentration and replacement therapy with neurotransmitters precursors (L-DOPA and 5-HTP) and supplements of folinic acid in DHPR deficiency.
Tetrahydrobiopterin is available as a tablet for oral administration in the form of "tetrahydrobiopterin dihydrochloride" (BH4*2HCL). BH4*2HCL is FDA approved under the trade name Kuvan. The typical cost of treating a patient with Kuvan is $100,000 per year. BioMarin holds the patent for Kuvan until at least 2024, but Par Pharmaceutical has a right to produce a generic version by 2020. BH4*2HCL is indicated at least in tetrahydrobiopterin deficiency caused by GTPCH deficiency or PTPS deficiency.
There is no broadly accepted standard of care for infants with DG. Some healthcare providers recommend partial to complete dietary restriction of milk and other high galactose foods for infants or young children with DG; others do not. Because children with DG develop increased tolerance for dietary galactose as they grow, few healthcare providers recommend dietary restriction of lactose or galactose beyond early childhood.
The rationale for NOT restricting dietary galactose exposure of infants and/or young children with DG: Healthcare providers who do not recommend dietary restriction of galactose for infants with DG generally consider DG to be of no clinical significance—meaning most infants and children with DG seem to be doing clinically well. Further, these providers may be opposed to interrupting or reducing breastfeeding when there is no clear evidence it is contraindicated. These providers may argue that the recognized health benefits of breastfeeding outweigh the potential risks of as yet unknown negative effects of continued milk exposure for these infants. For infants with DG who continue to drink milk, some doctors would recommend that blood galactose-1-phosphate (Gal-1P) or urinary galactitol be rechecked by age 12 months to ensure that these metabolite levels are normalizing.
The rationale FOR restricting dietary galactose exposure of infants and/or young children with DG: Healthcare providers who recommend partial or complete dietary restriction of galactose for infants and/or young children with DG generally cite concern about the unknown long-term consequences of abnormally elevated galactose metabolites in a young child's blood and tissues. Infants with DG who continue to drink milk accumulate the same set of abnormal galactose metabolites seen in babies with classic galactosemia – e.g. galactose, Gal-1P, galactonate, and galactitol – but to a lesser extent. While it remains unclear whether any of these metabolites contribute to the long-term developmental complications experienced by so many older children with classic galactosemia, the possibility that they might cause problems serves to motivate some healthcare providers to recommend dietary galactose restriction for infants with DG. Switching an infant with DG from milk or milk formula (high galactose) to soy formula (low galactose) rapidly normalizes their galactose metabolites. This approach is considered potentially preventative rather than responsive to acute symptoms.
If dietary galactose restriction of any kind is followed, healthcare providers may recommend that the child have a galactose challenge to re-evaluate galactose tolerance before the restrictive diet is discontinued. Most infants or young children with DG who are followed by a metabolic specialist are discharged from follow up after a successful galactose challenge.Options for those choosing to restrict dietary galactose in infancy and/or early childhood: Dietary restriction practices for Duarte galactosemia vary widely. In the US, some healthcare providers recommend full dietary restriction of milk and all dairy products for the first 12 months of life, followed by a galactose challenge. Some providers recommend the galactose challenge before 12 months, others after. Some providers who recommend dietary intervention suggest a "compromise approach" if the parent wishes to breastfeed, such that the parent alternates feedings of breast milk and low galactose formula. Finally, some parents choose to continue some form of dietary galactose restriction for their child with DG beyond early childhood.
What is a galactose challenge? The goal of a galactose challenge is to learn whether a child is able to metabolize dietary galactose sufficiently to prevent the abnormal accumulation of galactose metabolites, generally measured as Gal-1P in the blood. For infants with DG who showed elevated galactose metabolites at diagnosis, this test can be used to see if their ability to process galactose has improved enough to discontinue dietary galactose restriction.
To test galactose metabolism, a baseline Gal-1P level is measured while the child is on a galactose-restricted diet. If the level is within the normal range (e.g. <1.0 mg/dL), the parent/guardian is advised to "challenge" the child with dietary galactose—meaning feed the child a diet that includes normal levels of milk for 2–4 weeks. Immediately after that time, another blood sample is collected and analyzed for Gal-1P level. If this second result is still in the normal range, the child is said to have "passed" their galactose challenge, and dietary galactose restrictions are typically relaxed or discontinued. If the second test shows elevated Gal-1P levels, the parent/guardian may be advised to resume galactose restriction for the child, and the "challenge" may be repeated after a few months.
Raw eggs should be avoided in those with biotin deficiency, because egg whites contain high levels of the anti-nutrient avidin. The name avidin literally means that this protein has an "avidity" (Latin: "to eagerly long for") for biotin. Avidin binds irreversibly to biotin and this compound is then excreted in the urine.
To treat people with a deficiency of this enzyme, they must avoid needing gluconeogenesis to make glucose. This can be accomplished by not fasting for long periods, and eating high-carbohydrate food. They should avoid fructose containing foods (as well as sucrose which breaks down to fructose).
As with all single-gene metabolic disorders, there is always hope for genetic therapy, inserting a healthy copy of the gene into existing liver cells.
The treatment is some form of Vitamin E supplementation.
Aggressive vitamin E replacement therapy has been shown to either prevent, halt or improve visual abnormalities.
Currently, there is no specific treatment to correct the LCAT deficiency so therapy is focused on symptom relief. Corneal transplant may be considered for patients presenting with severely impaired vision caused by cholesterol corneal opacities. Dialysis may be required for patients presenting with renal failure, and kidney transplant may be considered.
Intake of carbohydrates which must be converted to G6P to be utilized (e.g., galactose and fructose) should be minimized. Although elemental formulas are available for infants, many foods contain fructose or galactose in the forms of sucrose or lactose. Adherence becomes a contentious treatment issue after infancy.
There is a deficiency of malate in patients because fumarase enzyme can't convert fumarate into it therefore treatment is with oral malic acid which will allow the krebs cycle to continue, and eventually make ATP.
Galactose is converted into glucose by the action of three enzymes, known as the Leloir pathway. There are diseases associated with deficiencies of each of these three enzymes:
Persistent elevation of uric acid above 6.5 mg/dl warrants treatment with allopurinol to prevent uric acid deposition in kidneys and joints.
Because of the potential for impaired platelet function, coagulation ability should be checked and the metabolic state normalized before surgery. Bleeding time may be normalized with 1–2 days of glucose loading, and improved with ddavp. During surgery, iv fluids should contain 10% dextrose and no lactate.
A patient with GSD, type 1b was treated with a liver transplant at UCSF Medical Center in 1993 that resulted in the resolution of hypoglycemic episodes and the need for the patient to stay away from natural sources of sugar. Other patients have undergone this procedure as well with positive results. Although a liver transplant resulted in the resolution of hypoglycemia it did not however resolve the chronic neutropenia and the risk of infection among patients.