Table 1.

Urea cycle patient subjects, clinical presentation, and molecular/enzymatic analyses

Condition	Subject	Presentation*	Diagnostic studies†
OTC female	1001	Late onset, symptomatic	PAA, OA, Linkage
	1002	Late onset, symptomatic	PAA, OA, DNA (IVS-1/codon 22 delG)
	1003	Late onset, asymptomatic	PAA, OA, Linkage
	1004	Late onset, asymptomatic	PAA, OA, Linkage
	1005	Late onset, asymptomatic	PAA, OA, Linkage
	1006	Late onset, asymptomatic	PAA, DNA (F354C)
	1007	Late onset, asymptomatic	PAA, DNA (F354C)
	1008	Late onset, asymptomatic	PAA, OA, Linkage
	1009	Late onset, asymptomatic	PAA, DNA (F354C)
	1010	Late onset, asymptomatic	PAA, DNA (F354C)
OTC male	1101	Neonatal	PAA, OA
	1102	Late onset	PAA, OA, Enz (220, control 3448)‡
	1103	Late onset	PAA, OA, DNA (F354C)
	1104	Late onset	PAA, OA, DNA (F354C)
	1105	Late onset	PAA, OA, DNA (A336C)
ASSD	2001	Neonatal	PAA, DNA (deletion exon 7), Enz (0, control 2.67)§
	2002	Neonatal	PAA, DNA (deletion exon 5), Enz (0, control 1.09)§
	2003	Neonatal	PAA, DNA (deletion exon 5),
	2004	Neonatal	PAA
	2005	Late onset	PAA, Enz (0, control 3.36)§
ASLD	3001	Neonatal	PAA, Enz (0, control 11.9)§
	3002	Late onset	PAA

^*Neonatal onset defined as symptomatic presentation in the first month of life, but invariably all neonatal patients presented in first week. Late onset is defined as second month and thereafter. Symptomatic refers to documented hyperammonemia requiring pharmacotherapy. Asymptomatic patients have not had documented hyperammonemia and do not require pharmacotherapy. However, these patients may exhibit signs of protein aversion. 

^† PAA, plasma amino acid profile; OA, urine orotic acid; Linkage, linkage analysis to independently diagnosed proband; DNA, mutation analysis of the respective genetic loci; Enz, enzymatic analysis for enzyme deficiency in the Baylor Biochemical Genetics Laboratory. 

^‡Enzyme assay on liver (activity in nmol/g tissue). 

^§Enzyme assay on primary fibroblasts (activity in nmol/h/mg).