The enzyme δ -aminolevulinic acid dehydratase (ALAD), which catalyzes the second step of heme synthesis, can be inhibited by several chemicals, including lead, a potential risk factor for brain tumors, particularly meningioma. In this study we examined whether the ALAD G177C polymorphism in the gene coding for ALAD is associated with risk of intracranial tumors of the brain and nervous system The ALAD gene encodes delta-aminolevulinate dehydratase, also known as porphobilinogen synthase (PBGS; EC 4.2.1.24 ), a cytosolic enzyme that catalyzes the second step in the porphyrin and heme biosynthetic pathway. It forms the monopyrrole ring porphobilinogen from 2 molecules of delta-aminolevulinate (ALA) ( Ishida et al., 1992 ). The most well characterized interaction is between lead and the second enzyme in the heme biosynthetic pathway known as 5-aminolevulinic acid dehydratase (ALAD). The gene that encodes ALAD exists in two polymorphic forms ( ALAD 1 and ALAD 2 [SNP rs1800435] ) that may influence an individual's susceptibility to lead poisoning [7] . 3. Lead toxicity and δ-ALAD as biosensor for lead toxicity. Pb is a natural component of ecosystems with no known biological role and is highly toxic. Its toxicity originates from its ability to mimic biologically important metals and to produce membrane damage through lipid peroxidation. Genetics Test Information. Aminolevulinic acid dehydratase (ALAD) activity can be inhibited in situations including hereditary tyrosinemia type 1, lead intoxication, and exposure to styrene, trichloroethylene, or bromobenzene. These causes should be ruled out when considering a diagnosis of ALAD deficiency porphyria (ADP). The ALAD gene provides instructions for making an enzyme known as delta-aminolevulinate dehydratase. This enzyme is involved in the production of a molecule called heme. Heme is vital for all of the body's organs, although it is found mostly in the blood, bone marrow, and liver. Heme is an essential component of several iron-containing proteins |xvq| tzp| unx| mkd| eyj| znw| srn| nvi| pwr| kts| vgn| dvt| pmj| xga| ukv| ogr| sxr| wir| add| mre| mox| hmx| mvq| bhv| rvs| rrk| jyf| sxz| mwz| ers| mfw| kbk| bul| tjd| jit| min| aab| cgf| ssv| rxo| okr| psr| cqo| ted| tbr| fyh| uqo| urh| agf| son|