Question

Hydroxymethylbilane is converted to uroporphyrinogen III via the enzyme uroporphyrinogen III synthase (heme synthesis). Defects in this enzyme cause which condition?

1) Congenital erythropoietic porphyria
2) Hemochromatosis
3) Sickle cell anemia
4) Thalassemia

Answer 1

Defects in the enzyme uroporphyrinogen III synthase cause Congenital erythropoietic porphyria, a condition leading to disrupted heme synthesis in red blood cells.

Step-by-step explanation:

Defects in the enzyme uroporphyrinogen III synthase lead to the condition known as Congenital erythropoietic porphyria.

This enzyme is vital in the biosynthesis of heme, where hydroxymethylbilane is converted into uroporphyrinogen III, a key precursor in the formation of heme, which is ultimately used to form hemoglobin. Congenital erythropoietic porphyria is a type of porphyria that affects the red blood cells' heme synthesis pathway, resulting in an increase in porphyrins due to a disruption in this critical biosynthetic route.