Transient hyperphenylalaninemia UMLS:C0268464 A condition of not having consistently high levels of phenylalanine in the blood but of experiencing temporary hyperphenylalaninemia following ingestion of large quantities of phenylalanine (for instance, following an oral loading test with phenylalanine). HP:0008297 SNOMEDCT_US:28575006 Abnormal circulating phenylalanine concentration