Mutation Report for: D70G_human-BCHE
D70G_human-BCHE | Gene_locus | human-BCHE |
| Torpedo_number | 72 |
| AA_Change | D70G |
| Mode_of_mutation | Site directed mutagenesis |
| | Natural mutant |
| Modification | Peripheral Anionic Site |
| | Succinylthiocholine binding |
| | Aging |
| | Atypical variant |
| Summary (8) |
| Paper (29) |
| Kinetic_parameter (36) |
| Comment | p.D70G Asp70Gly c.293A>G (p.D98G Asp98Gly in primary sequence with 28 amino-acids signal peptide) rs1799807, Atypical variant, CHE1*A, Dibucaine-resistant I CHE*70G, the classic deficiency variant described by Kalow and Gunn (1959), Kalow and Staron (1957) , has a homozygote frequency of about 1:3,000 in white North Americans. (from OMIM) McGuire et al. (1989) found that a mutation in nucleotide 209, which changes codon 70 from GAT to GGT, was the abnormality in all 5 atypical cholinesterase families examined. The mutation caused the loss of a Sau3A1 restriction site. The gene change results in a substitution of glycine for aspartic acid as amino acid 70. This is an acidic to neutral amino acid change which accounts for the reduced affinity of atypical cholinesterase for choline esters. Aspartic acid must be an important component of the anionic site. Atypical BCHE, the classic deficiency variant described by Kalow (1962), Kalow and Gunn (1959), Kalow and Staron (1957), has a homozygote frequency of about 1:3,000 in white North Americans. In the nomenclature system of La Du et al. (1991), this allelic variant is referred to as CHE*70G. Reduced enzyme activity with butyrylthiocholine as substrate; ; 2-fold lower affinity for butyrylthiocholine; 10-fold lower affinity for butyrylthiocholine at homozygosity rs1799807 |
| Xenobiotic_sensitivity | Defect in Suxamethonium hydrolysis |
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