Fatty Oxidation Disorders are autosomal recessive disorders affecting both males and females. Both parents are carriers of an abnormal gene, in that when two abnormal genes unite the child will have an FOD. There is a 25% chance that each child will have an FOD and a 75% chance of being a carrier or not having the disorder at all. If one child is diagnosed with an FOD, their siblings should also be tested, even if they are asymptomatic.
These disorders are diagnosed in a variety of ways at specialized labs across the country. Also refer to this information on diagnosis of mitochondrial disorders. Blood, urine, skin fibroblasts, amniocytes (from amniotic fluid) and muscle and liver tissue are some of the specimens analyzed. The diagnostic tests often include an acylcarnitine profile, urine organic acid analysis, carnitine levels and enzyme assays in fibroblasts. The acylcarnitine profile with whole blood on a ‘PKU card’ (filter paper card) is the most direct approach for diagnosis of most of the FODs. Many Drs are now also prescribing for whole exome or genome testing to gather more information and possibly a diagnosis, especially if some of the other testing is inconclusive.
Treatment for FODs is multidimensional. A major concern is to avoid going without food/calories for beyond 8-12 hours (i.e., an overnight sleep for a child or adult, when well.) It is strongly recommended, however, for infants under age 6 months, they should be fed around the clock every 2-4 hrs. Most children/adults with an FOD eat often throughout their waking hours (i.e., every 3-6 hrs) ~ the interval depends on various factors and their specific circumstances, such as if they are ill versus well, in which case they most likely would try to eat/drink more often around the clock. Please note that fasting times can vary from person to person within the different disorders. A fasting state, especially while ill, can trigger a “metabolic crisis” leading to lethargy and hospitalization.
Several snacks and meals of lowfat/high carbohydrate foods ~ such as cereal, pasta, and other complex carbohydrates (as well as sugar drinks when not well) ~ are recommended throughout the day. Additionally, some families use various supplements (i.e., riboflavin, coQ10) and MCT Oil (not used for all FODs, especially MCAD, since the medium chain triglycerides cannot be broken down). Infants under six months or so should continue to have at least one night feeding/snack as they should not go 10-12 hours without eating. If the FOD child/adult has experienced hypoglycemia (even with frequent meals), in order to help decrease the frequency of low blood sugar in the morning, some find it helpful to mix in 1-3 tablespoons of raw corn starch (i.e. Argo) to a cold sugar-free liquid or food at night ~ be aware that too much corn starch can be constipating for some individuals. Please also note that cornstarch is NOT recommended for children under one year of age because they often lack the necessary pancreatic amylase to digest the cornstarch. Cornstarch can also be very hard on teeth ~ so be sure to brush after eating/drinking the cornstarch.
Some physicians prescribe the FDA-approved drug Carnitor® (manufactured by Leadiant Biosciences) as an L-carnitine supplement for several FODs, especially if carnitine deficiency is a secondary disorder. [Please note: There is now an FDA-approved generic form of l-carnitine (levocarnitine) along with the brand name Carnitor®.] Although carnitine is made within the body, sometimes supplementation is necessary. L-carnitine helps the body’s metabolism run smoothly. It is useful in preventing low blood sugar and assists in removing metabolic wastes from the cells so a buildup of toxins will not occur. Please note that the health food store carnitine is NOT the same as the prescribed drug Carnitor®, (or the prescription generic drug form) and using it in place of the prescribed drug may be dangerous.
As with any medical condition, discussing treatment options with your physician(s) and FOD specialists is necessary for the well-being of anyone with an FOD. Please do not make any changes in your child’s or your own treatment without first consulting with your physician(s).
If hospitalized, it is imperative, according to FOD specialists, that a 10% dextrose IV (5% is NOT enough) is started immediately following blood chemistry samplings ~ waiting hours for the results before putting in the IV can be fatal when an FOD child/adult is in crisis. The 10% dextrose/glucose gives NEEDED FUEL to the brain and body that normal saline IV cannot provide. Also note that even though the child/adult may appear to be hydrated, it does NOT mean they are not heading toward a crisis ~ they may have fluids onboard, but they NEED CALORIES to help them prevent and/or get through a metabolic crisis/stress. Many experts also recommend the use of carnitine (Carnitor® or Levocarnitine – prescribed drugs) and if one cannot keep oral carnitine down due to vomiting, there is an IV carnitine available for emergencies.
Too many children/adults have been sent home from the ER because they didn’t LOOK sick ~ those with FODs do not have any kind of ‘look’ so INSIST that the blood and urine chemistries are done to determine what is going on INSIDE their bodies!