1. ONLINE SUPPLEMENT Infantile cases of sitosterolaemia with novel mutations in the ABCG5 gene: Extreme hypercholesterolaemia is exacerbated by breastfeeding CONTENTS Supplemental Fig. 1. Pedigree of the sitosterolemic subjects………………………………………..…………………. Supplemental Fig. 2. Intertriginous xanthomas before and after the treatment in Case 1……………………………… Supplemental Fig. 3. Intertriginous xanthomas in Case 3……………………………………………………………… Supplemental Fig. 4. Intertriginous xanthomas in Case 4 ……………………………………………………………... Supplemental Table 1. Clinical data of the pedigree (Family 1) ………………………………………………………. Supplemental Table 2. Clinical data of the pedigree (Family 2) ………………………………………………………. Supplemental Table 3. Clinical data of the pedigree (Family 3) ………………………………………………………. 1 23456782345678

2. Supplemental Fig. 1. Pedigree of the sitosterolemic subjects 2

3. AB CD Supplemental Fig. 2. Intertriginous xanthomas before and after the treatment in Case 1 3

4. 4 Supplemental Fig. 3. Intertriginous xanthomas in Case 3 AB

5. 5 Supplemental Fig. 4. Intertriginous xanthomas in Case 4 AB

6. Supplemental Table 1. Clinical data of the pedigree (Family 1) 6 Subject (gender) I.1 (male) I.2 (female) II.1 (male) II.2 (female) II.3 (female) II.4 (female) III.1 Case 1 (female) III.2 Case 2 (female) ABCG5 genotypeW/M1W/WM2/WW/M1 M2/M1 Age (yr)59583133312910 TC (mg/dl)293179185284205226523555 TG (mg/dl)19668431485561244534 HDL-C (mg/dl)4075719071685934 LDL-C (mg/dl)214150105164120146407NA ApoA-I (mg/dl)116164NA148140148115NA ApoB (mg/dl)16467NA1258099232NA ApoE phenotype4/33/23/33/24/24/33/24/3 CETP (μg/ml)3.82.32.14.42.63.35.02.6 Sitosterol (μg/ml)132.29.814.613.810.610133.4 Lathosterol (μg/ml)2.40.6NA2.91.10.90.6NA Campesterol (μg/ml)191.8NA12.24.85.022.9NA Cholestanol (μg/ml)4.15.5NA2826.413.941.7NA ABCG5 genotype:W=wild type, M1=c.1306G>A, M2=c.1813_1817delCTTTT

7. 7 Subject (gender) I.1 (male) I.2 (female) I.3 (female) II.1 (male) II.2 (male) II.3 (female) III.1 (male) III.2 Case 3 (female) ABCG5 genotypeW/M1W/WM3/WW/M1W/WM3/WW/M1M3/M1 Age (yr)6360733634 51 TC (mg/dl)226222319238213318176870 TG (mg/dl)5954505151879155260 HDL-C (mg/dl)38554140561073848 LDL-C (mg/dl)176166NA174140182127796 ApoA-I (mg/dl)166142151NA150NA108NA ApoB (mg/dl)109113148NA107NA88NA ApoE phenotype3/3 3/23/3 3/23/3 CETP (μg/ml)1.92.74.32.0 4.83.73.4 Sitosterol (μg/ml)7.93.216.17.42.7187.980 Lathosterol (μg/ml)1.34.24.12.85.61.111 Campesterol (μg/ml)146.128.412.95.626.613.265.4 Cholestanol (μg/ml)4.23.812NA3.9NA3.3NA ABCG5 genotype:W=wild type, M1=c.1306G>A, M3=c.130C>T Supplemental Table 2. Clinical data of the pedigree (Family 2)

8. 8 Subject (gender) II.1 (male) II.2 (male) III.1 Case 4 (male) ABCG5 genotypeM4/WW/M2M4/M2 Age (yr)34382 TC (mg/dl)223185756 TG (mg/dl)5548147 HDL-C (mg/dl)745142 LDL-C (mg/dl)126127589 ApoA-I (mg/dl)NA 97 ApoB (mg/dl)NA 291 ApoE phenotype3/3 3/2 CETP (μg/ml)2.0 3.7 Sitosterol (μg/ml)5.35115 Lathosterol (μg/ml)4.71.2 Campesterol (μg/ml)10.6994.6 ABCG5 genotype:W=wild type, M4=c.1336C>T, M2=c.1813_1817delCTTTT Supplemental Table 3. Clinical data of the pedigree (Family 3)