Table 1.

Effect of Biotin Substitution on 3-HIVA and 3-MCG Concentration in Urine

		Concentration in Urine ofb (mmol/mol creatinine)
Subject andBiotin Substitution	Time after Leucine Loada(h)	3-HIVA	3-MCG
MCC047:
No biotin	…	276	653
10 mg/d for 7 d	…	358	300
40 mg/d for 7 d	…	135	44
40 mg/d for 3 more wk	…	17	9
Father of MCC047:
No biotin	…	26	ND
Mother of MCC047:
No biotin	…	24	ND
MCC048:
No biotin	Before load	105	2.2
No biotin	0–2	183	12
No biotin	2–4	956	33
No biotin	4–6	794	35
No biotin	Before load	100	ND
5 mg/kg with leucine at 0 h	0–2	368	6.2
No biotin	2–4	471	25
No biotin	4–6	335	12
Controls:
No biotin	…	<18	ND

^aPatient MCC048 was given a leucine load of 150 mg/kg with and without a simultaneous biotin load, and urine was collected in three portions after the load.

^bND = not detectable.