Table 1.

Chromosomal locations of genes encoding enzymes of the heme biosynthesis pathway and genes linked to development of late-onset Alzheimer's disease.

Heme biosynthetic enzymes	Location1	Closest
		AD-related loci2
ALAS-1 (EC 2.3.1.37)	3p21	3p14, 3p26
ALA-dehydratase	9q34	9q34
(EC 4.2.1.24)3
Porphobilinogen	11q23.3	11q25
deaminase (EC 4.3.1.8)3
Uroporphyrinogen	10q25.3	10q21–10q25
III synthase (EC 4.2.1.75)
Uroporphyrinogen	1p34	1p31–1p36
decarboxylase (EC 4.1.1.37)
Coproporphyrinogen	3q12	3q28
III oxidase (EC 1.3.3.3)3
Protoporphyrinogen	1q22	1q23, 1q24
oxidase (EC 1.3.3.4)3
Ferrochelatase	18q21.3	18q22
(EC 4.99.1.1)

¹ from Meissner et al [10].

² From Table 1 by Kamboh in [48].

³ A deficiency is associated with a specific form of acute hepatic porphyria.