The most common therapies for PKU are dietary modification and the use of phenylalanine restriction. PKU patients treated with dietary restriction demonstrate improved outcomes. However, this therapy is difficult to consistently enforce, and must be evaluated for its efficacy.
Phenylketonuria type 1 is not always curable. The only reliable cure is a reduction of excreted phenylalanine loads, achievable by means of the diet of PNU 1 children and a low protein diet. This treatment option is therefore available only to several hundred children per country. PNU type 2 is cured with the diet alone.
Approximately 50,000 babies in the United States are affected with PKU each year. Because mothers will often begin showing symptoms of PKU before giving birth, many of these cases are detected during pregnancy. Inadequate vitamin supplementation before or during pregnancy results in the early death of a fetus. Most cases of PKU are now undetected or unrecognized.
Phenylketonurias may have a genetic component and most cases occur due to mutations in the PHYKD gene. As such, a mutation in this gene may be responsible for the disease. This is most likely due to a problem with the transfer of a pyrimidine riboswitch into the correct mRNA during transcription. This can result from either a translational error in the mRNA, or a change in the mRNA itself. PKS is a hereditary disorder which is due to changes in phenylalanine metabolism. There is a deficiency of α-phenylalanine, leading to its accumulation in urine.
In these patients, PKU can cause irreversible neurological damage by the toxic metabolic products of PKU that must be avoided. This toxic effect can occur at lower levels and may be masked by normal intellectual function. PKA patients should be referred for specialist help at a PKA clinic where treatment can prevent permanent brain damage. Some PKU patients may be able to have a normal intelligence and a normal school life.
PKU is a recessive genetic disorder affecting brain function and is characterized by mental retardation, growth retardation, visual and auditory impairment, and epileptic seizures. The incidence of PKU is estimated to be 1 in 50,000 in the USA.
Rtx-134, unlike the standard care, provided significant and sustained improvement in PKA, leading to a highly beneficial and sustained clinical effect. Rtx-134 treatment was well tolerated, with an acceptable safety profile. Results from a recent clinical trial support the trial as a viable clinical option for children and adolescents with PKU. (Psycinfo®; doi:10.1023/CEC-010612-061400).
Current results on these new rtx-134 analogues show a high potential as an active therapeutical drug for the treatment of phenylketonuria. However, additional pre-clinical testing needs to be undertaken with these analogues to determine their role in the treatment of PKU.
Rtx-104 showed improvements in glycemic control and weight loss, as measured by HbA1c, post-prandial glucose, and weight change, but did not achieve improvement as measured by the weight reduction and QoL, in patients with phenylketonuria.
Phenylketonurias remains understudied. [Somatoform disorder (F48.8) (N88.1)] is a more recent syndrome and [Mood disorder (F34.8) (N88.0)] was once thought to be a subtype of the older entity Sudden infant death syndrome (SIDS). Current research is focused on understanding the pathophysiology of the disease, its neuropathology and its familial and genetic predispositions. The [World Federation for Phenylketonurias] is undertaking a major scientific and technical update (https://worldfamphen.info/en/aboutus).
These families are a useful model for the investigation of PKU. One of the strongest factors identified was autosomal dominant inheritance in the probands' families. Inheritance in the parents of the PKU probands was shown to be rare.
Rtx-134 is known to cause many side-effects, including increased uric acid levels, and it is often omitted from clinical studies of ritonavir. We show that Rtx-134, added to ritonavir, might be more effective due to decreased uric acid-raising action. Findings from a recent study might have also clinical and social significance on two levels, as ritonavir is commonly used in human health care.