Proteins Membrane proteins Microbes Biotin KAP OR PLXA ATX Titin (μg/mg serum protein)   (%) total  free (μg/mL serum) Children’s serum Child patient 1 with GSD1b (3 y, female) Before biotin + ND ND ND ND 84 14.9 3.08 ND After biotin (32 w) ND ND ND ND ND 32 18.4 9.43 1.78 Child patient 2 (3 mo, male)  Before biotin + ND ND ND ND 38 16.2 2.31  0.54 After biotin (13 w) ND ND ND ND ND 18  15.0 3.89 0.23 Child patient 3 (1 y, female) Before biotin + ND ND ND ND 55 14.3 2.03 0.036 After biotin (16 w) ND ND ND ND ND 10 21.6 2.56 0.31 After biotin (44 w) ND ND ND ND ND 44 17.5 7.25 0.10 Healthy baby control 4 (8 mo, female) (gastritis)   ND ND ND ND ND 7.0 7.9 3.21 0.18 Healthy but inflammatory control 4’ (12 mo, female)   ND ND ND ND ND 24 15.4 3.22 0.66 Adult’s serum Adult patient 5 with gait disorder and contraction (narrowing of visual field) (32 y, female)   ND + + + + 62 18.5 1.14 0.04 Adult patient’s sister 6 with light gait disorder (younger sister; 22 y, female)   ND ND + ND + 44 18.3 1.29 0.07 Adult patient’s healthy mother 7 (52 y, female)   ND ND ND ND + 44 10.8 1.68 NM Adult healthy control 8 (33 y, male)   ND ND ND ND + 38 4.5 1.80 0.12

*PLXA; plexin A. ATX; ataxin. ND; not detectable. NM; not measured. OR and PLXA are protein-fragments without glycochains. KAP of Child patient 1 is 4-1, Child patient 2 is 5-5, Child patient 3 is 4-8, respectively, and all is ultra-high cysteine (UHS) type containing more than 30 mol % cysteine. Other conditions were as described in the Materials and Methods section. Healthy control serum contained proteins of microbes at 4.5 and 7.9 %.

Table 2: Summary of various characteristics in the biotin deficient patients and healthy controls*.