Medical Genetics Phenylalanine Phenylpyruvic acid Phenylalanine Albinism hydroxylase block Tyrosine 3, 4-dihydroxyphenylalanine Melanin pigments (DOPA) y rosine -CO2+ H2 transaminase Citric acid cycle p-hydroxyphenylpyruvic acid Fumaric Acetoacetic acid acid p-hydroxyphenylpyruvic Fumarylacetoacetic acid acid oxidase Homogentisic acid oxidase Homogentisic acid 2, 5-dihydroxyphenylacetic acid Maleylacetoacetic acid Albinism (Klug& Cummings 1997)Medical Genetics