Increased Occurrence of Valproic Acid-Induced Hyperammonemia in Carriers of T1405N Polymorphism in Carbamoyl Phosphate Synthetase 1 Gene

Table 2

Distribution of CPS1 genotypes for the T1405N polymorphism in patient with normal ammonia level and patients with hyperammonemia (HA, defined as ammonia plasma level >65 µmol/L).

	CC genotype	CA genotype	AA genotype	Numbers of carriers of minor A allele (percentage)	Minor allele frequency
Patient with normal ammonia level (𝑁=131)	68 (52%)	54 (41%)	10 (7%)	64 (45%)	0.28
Patients with HA (𝑁=11)	1 (9%)	7 (64%)	3 (27%)	10 (91%)*	0.6

Results are expressed as absolute numbers of patients (percentage). CC denotes homozygosity for the C-encoded Thr1405 variant, AA homozygosity for the A-encoded Asgn1405 variant, and CA heterozygosity for this polymorphism. ^∗𝑃=0.009 by logistic regression and Fisher’s exact test.