The gene encoding the enzyme is referred to as DDC is located on chromosome 7 in humans. It consists of 15 exons encoding a protein of 480<unk> <unk> s. Single nucleotide polymorphisms and other gene variations have been investigated in relation to neuropsychiatric disorders, for example, a one-base pair deletion at 601 and a four-base pair deletion at 722–725 in exon 1 in relation to bipolar disorder and autism. No direct correlation between gene variation and autism was found. More than 50 mutations of DDC have been correlated with<unk>  deficiency This condition is most prevalent in Asia, presumably due to the founder effect. Alternative splicing events and promoters have been observed that lead to various forms of the<unk>  enzyme. Unique usage of certain promoters leads to transcription of only the first exon to produce an extra-neuronal isoform, and splicing of exon 3 leads to a product devoid of enzymatic activity. Analyses via porcine specimens have elucidated two<unk>  isoforms – resulting from exclusion of exon 5 and exons 5 and 6 – that lack a portion of the decarboxylating domain.
Aromatic L-amino acid decarboxylase
Phenylalanine hydroxylase
Monoamine oxidase B
Catechol-O-methyltransferase
Tyrosine hydroxylase
Dopamine beta-hydroxylase
Monoamine oxidase A
Monoamine oxidase