Deficiencies in<unk> s result in decreased ability to oxidize fatty acids, thereby signifying metabolic dysfunction. Medium-chain<unk>  deficiencies (MCADD) are well known and characterized because they occur most commonly among<unk> s, leading to fatty acid oxidation disorders and the potential of life-threatening metabolic diseases. Some symptoms of medium-chain<unk>  deficiency include intolerance to fasting, hypoglycemia, and sudden infant death syndrome. These symptoms are seen as directly connected to the inability to metabolize fats. Intolerance to fasting and hypoglycemia result from the inability to gain energy and make sugar from fat stores, which is how most of humans' excess energy is stored. Also, fatty acids can begin to accumulate in the blood, lowering the blood's pH and causing acidosis. MCAD is related to / has an association with Sudden Infant Death. Approximately 90% of cases of MCAD are due to a single point mutation where the Lysine at position 304 (Lys304)is replaced by a Glutamate residue and this prevents the enzyme from properly functioning. It is reported that, every year, 1 in 20,000 infants is born with a deficiency in his/her medium-chain<unk> s that is caused by a mutation. The mutation is recessive, and often parents of children who suffer from the deficiency can be diagnosed afterward as carriers. In humans the most common naturally occurring mutation in MCAD is located at amino acid residue Lys-304. The altered residue occurs as a result of a single-point mutation in which the lysine side chain is replaced by a glutamate. Lys-304 typically interacts with surrounding amino acid residues by forming hydrogen bonds with Gln-342, Asp-300, and Asp-346. When a mutation causes glutamate to take the place of lysine, an additional negative charge is introduced at that site, which disrupts the normally occurring H-bonding. Such a disruption alters the folding pattern of the enzyme, ultimately compromising its stability and inhibiting its function in fatty acid oxidation. The efficiency of the mutated protein is about 10 times lower than that of the natural protein. This can lead to the symptoms of the deficiency listed above.
Acyl-CoA dehydrogenase
Pyruvate carboxylase
Phenylalanine hydroxylase
Aldehyde dehydrogenase
Glutamate dehydrogenase
Butyrate esterase
Glycogen phosphorylase isoenzyme BB
Monoamine oxidase B