Background
Phenylketonuria (PKU) is one of the preventable causes of intellectual disability. It is the most prevalent disorder of amino acid metabolism in the white population.
Aim and objective
The following were the aims and objectives of the study: first, assessment and correlation of clinical and biochemical progress of patients; second, assessment of the effect of age at diagnosis on the clinical outcome, third, follow-up of dietary compliance of patients; and third, phenylalanine hydroxylase gene sequencing for selected cases.
Participants and methods
This paper investigated 104 patients with PKU, including 79 early-diagnosed patients, 22 late-diagnosed patients, and three untreated patients, regarding clinical characteristics and Phe metabolic control. Thorough history taking, clinical and neurological assessment, and follow-up of dietary compliance with monthly assessment of blood Phe levels were performed. Four patients were selected for phenylalanine hydroxylase gene sequencing as a pilot study.
Results
Regarding early-diagnosed patients, 3.8% had attention-deficit and hyperactivity disorder. As for the late-diagnosed patients, 68.2% showed abnormal behavior, with an intelligent quotient range of 38.0–90.0. Hyperactivity was detected in 33.3%% of the untreated group, and the intelligent quotient ranged from 45.0 to 67.0. Parental consanguinity was found in 67.3% of cases. On average, 72% of patient had well-controlled blood phenylalanine levels.
Conclusion
There is a wide range of clinical heterogeneity among patients with PKU. Several factors determine the clinical outcome, including age at diagnosis, untreated blood phenylalanine levels, degree of compliance to dietary therapy, interventional therapies, as well as blood–brain barrier selectivity.