Medical Genetics In Type 1 albinism defects in the metabolism of tyrosine lead to failure in converting this amino acid to melanin. This is due to a genetic defect in tyrosinase -- the enzyme responsible for metabolizing tyrosineMedical Genetics In Type 1 albinism defects in the metabolism of tyrosine lead to failure in converting this amino acid to melanin. This is due to a genetic defect in tyrosinase -- the enzyme responsible for metabolizing tyrosine