Supplementary File 1. Identity-by-descent allele-sharing analysis of 12q23 region in families with HELLP: microsatellite markers Legends Identity-by-descent (IBD) allele-sharing analysis in families with HELLP was performed with 26 microsatellite markers covering the 23.6 Mb region on 12q23 between D12S309 and D12S395. Non-parametric multipoint linkage (Allegro 2) complemented by pedigree analysis was performed in 7 HELLP families with affected sisters (families 1-7), 4 families with affected cousins (families 8-11) and 1 family with discordant monozygotic twin sisters (family 12). A total of 57 individuals with 36 affected females was analyzed. Supplementary File 1A: Multipoint linkage analysis using Smnallele indicates the 4 marker region between PAH and D12S1647 with LOD and NPL scores >3 (box). Supplementary files 1B-D: Pedigree analysis indicates the same region with the presence of two minimal critial regions (I: D12S1607-PAH, II: D12S338-D123S317) in affected sister-pairs (1B), affected cousin pairs (1C) and discordant monozytic twin sisters (1D). Note the informative situation in family 11 (HELLP_93113) (1C) where two sisters from one family married two brothers from an unrelated family. In the affected cousins (93113/89, 93113/90) born from these couples, both alleles need to be shared in the region with linkage, as if these cousins were sisters. In the affected cousins (93113/89, 93113/90), both regions are supported. In their affected mothers (93113/12, 93113/8), maximal allele sharing is limited to the first region near D12S1030. Supplementary File 1A: Multipoint linkage analysis of families with HELLP Locationa LODb Dhatc NPLd Zlre Nplexactpf Infog Markerh 0.000 1.5181 1.0073 2.2686 2.6440 0.011835 0.7366 D12S1030 1.310 3.1605 1.9446 3.1727 3.8150 6.33e-04 0.6797 PAH 2.370 3.0472 1.7177 3.1866 3.7461 6.32e-04 0.7353 D12S360 3.510 3.1617 1.7433 3.2279 3.8158 5.99e-04 0.7518 D12S338 5.230 3.1711 2.1601 3.0243 3.8215 0.001445 0.6280 D12S1647 6.370 2.7642 1.9023 2.8938 3.5679 0.001939 0.6059 D12S317 8.090 2.5003 1.4707 2.8614 3.3933 0.002271 0.7158 D12S1597 8.100 2.4982 1.4677 2.8610 3.3919 0.002271 0.7170 D12S1683 8.650 2.6017 1.6258 2.8584 3.4614 0.002389 0.6648 D12S1605 Abbreviations: a. Relative location in cM, b. Allele sharing logarithm of the odds score, c. Maximum likelihood estimator of δ (difference), d. Non-parametric linkage score, e. Zlr: normalized likelihood ratio statistic for linkage, f. p value for NPL, g. Informativity (maximum 1.0), h. Microsatellite marker. For clarity, only the outcome for 9 of the 26 markers is shown. Supplementary File 1B: Affected sister-pairs 1 2 3 4 5 6 7 HELLP_8503 HELLP_9265 HELLP_9401 HELLP_9508 HELLP_9515 HELLP_9536 HELLP_94104 8 9 8 9 8 9 8 9 8 9 8 9 8 9 # Marker Position PIH PIH PIH PIH 1 D12S309 94989229 136 144 140 146 146 146 136 146 136 136 136 136 136 148 2 D12S1716 95469203 201 205 207 209 203 205 205 205 203 207 205 207 203 203 3 D12S1300 97025042 119 123 119 127 123 119 119 119 123 119 119 119 119 119 119 119 123 119 119 123 127 123 123 119 4 D12S1063 97223531 211 215 219 220 207 211 215 220 220 220 207 219 5 D12S306 99116489 198 222 218 224 218 224 214 222 204 218 6 D12S1041 99982385 140 149 146 149 140 149 140 146 140 140 140 149 7 D12S1727 100225071 173 179 173 175 171 173 171 173 8 D12S1607 100782813 137 151 137 155 151 153 155 155 137 155 151 155 151 151 9 D12S1030 101448930 251 251 251 255 255 271 251 255 251 255 247 255 10 PAH 101789858 245 241 233 253 233 245 253 241 245 233 237 229 233 245 245 241 237 245 257 241 11 D12S360 102603188 213 213 217 213 211 219 213 213 217 213 213 213 217 213 217 213 213 227 221 12 D12S338 103065489 261 265 265 267 261 265 267 265 265 265 265 265 267 265 265 265 261 267 265 275 261 267 13 D12S1647 103613187 193 193 191 191 191 193 187 191 191 189 191 195 193 191 193 191 193 187 191 191 191 14 D12S317 104120682 268 250 252 252 252 252 252 250 270 250 268 250 250 268 252 250 252 15 D12S1597 104275626 221 207 205 215 217 207 223 221 221 223 205 201 215 205 221 207 205 207 205 209 215 217 16 D12S1683 104709609 230 234 234 230 230 230 230 230 242 234 230 230 228 230 242 234 230 234 230 248 17 D12S1605 107227970 201 201 203 197 201 197 201 201 201 203 201 197 199 201 201 201 203 201 18 D12S84 107546196 199 215 213 215 213 219 199 201 19 D12S105 107799269 143 147 143 143 145 143 151 145 143 137 143 143 145 136 145 143 143 147 151 143 143 20 D12S1583 108309051 239 247 225 221 225 239 225 221 243 223 221 225 237 225 235 225 225 221 221 21 D12S1344 110809745 235 235 235 241 239 227 235 239 235 229 239 235 235 235 239 235 241 22 D12S1616 111778551 219 217 215 215 217 219 215 215 219 219 215 217 219 215 215 217 23 D12S354 113611973 197 187 187 191 199 187 197 191 191 187 187 197 187 187 191 197 24 D12S1665 114557056 225 227 225 225 225 225 225 225 225 25 D12S366 117056989 187 195 189 195 189 189 187 193 26 D12S395 118672843 240 240 224 236 240 240 244 228 240 236 240 240 224 236 248 248 240 240 236 0 1 0 1 0 1 0 2 0 1 0 1 0 1 HELLP HELLP HELLP PE + HELLP HELLP HELLP HELLP HELLP HELLP HELLP HELLP PE + HELLP HELLP HELLP + E # Marker Position 75 76 79 80 81 82 83 84 85 86 87 88 94 95 1 D12S309 94989229 136 144 136 144 140 146 140 146 146 146 146 146 136 146 136 146 136 136 136 136 136 136 136 136 136 148 136 148 2 D12S1716 95469203 201 205 201 205 207 209 207 209 203 205 203 205 205 205 205 205 203 203 203 207 205 207 205 207 203 203 203 203 3 D12S1300 97025042 119 119 119 119 127 119 127 119 119 119 119 119 119 119 119 119 119 119 119 123 119 123 119 123 127 119 127 119 4 D12S1063 97223531 211 215 211 215 219 220 219 220 207 211 207 211 215 220 215 220 220 207 220 215 220 220 220 220 207 219 207 219 5 D12S306 99116489 198 222 198 222 218 224 218 224 218 224 218 224 214 222 214 222 214 220 214 204 218 216 224 218 204 218 204 218 6 D12S1041 99982385 140 149 140 149 146 149 146 149 140 149 140 149 140 146 140 146 149 149 149 140 140 140 140 140 140 149 140 149 7 D12S1727 100225071 173 179 173 179 173 175 173 175 171 173 171 173 171 173 171 171 179 167 179 173 175 175 171 171 171 173 171 173 8 D12S1607 100782813 137 151 137 151 137 155 137 155 151 153 151 153 155 155 155 155 137 155 137 155 151 155 151 151 151 151 151 151 9 D12S1030 101448930 251 251 251 251 251 255 251 255 255 271 255 271 251 255 251 255 251 255 251 255 247 255 247 255 247 247 251 251 10 PAH 101807288 245 233 245 233 253 253 253 253 241 245 241 245 233 237 233 237 229 245 229 245 245 245 245 241 237 241 237 241 11 D12S360 102603188 213 217 213 217 213 213 213 213 213 213 213 213 213 217 213 217 213 217 213 217 213 219 213 213 213 221 213 221 12 D12S338 103065489 261 265 261 265 267 267 267 267 265 265 265 265 265 267 265 267 265 265 265 265 261 267 261 267 265 267 265 267 13 D12S1647 103613187 193 191 193 191 191 187 191 187 191 189 191 189 191 193 191 193 191 193 191 193 191 193 191 193 187 191 187 191 14 D12S317 104120682 268 252 268 252 252 252 252 252 250 270 250 270 250 268 250 268 250 250 250 250 276 250 276 252 268 252 268 252 15 D12S1597 104275626 221 205 221 205 215 223 215 223 221 223 221 223 205 215 205 215 205 207 205 207 205 205 205 207 205 217 205 217 16 D12S1683 104709609 230 234 230 234 230 230 230 230 230 234 230 234 230 228 230 228 230 234 230 234 242 230 242 234 230 248 234 248 17 D12S1605 107227970 201 203 201 203 197 197 197 197 201 201 201 201 203 197 203 197 199 201 199 201 201 199 201 201 201 201 201 201 18 D12S84 107546196 199 215 199 215 213 215 213 215 213 219 213 219 199 201 199 201 199 215 199 205 201 219 201 217 19 D12S105 107799269 143 143 143 143 143 151 143 151 145 137 145 137 143 143 145 136 145 136 145 143 143 143 143 151 143 147 143 20 D12S1583 108309051 239 225 239 225 221 225 221 225 221 223 221 223 221 237 221 237 225 235 225 235 225 225 225 231 225 221 225 221 21 D12S1344 110809745 235 235 235 235 235 227 235 227 235 239 235 239 235 239 235 239 235 235 235 235 235 241 235 235 235 241 239 241 22 D12S1616 111778551 219 215 219 215 215 215 215 215 215 219 215 219 219 217 219 217 219 215 219 215 217 217 217 215 217 215 217 217 23 D12S354 113611973 197 187 187 187 191 197 191 197 191 187 191 187 187 197 187 197 187 187 187 187 191 187 197 187 197 191 197 195 24 D12S1665 114557056 225 225 225 225 225 225 225 225 227 225 225 225 225 225 225 223 227 225 233 221 233 225 25 D12S366 117056989 191 195 187 195 187 195 189 195 189 195 193 195 189 189 189 189 193 189 193 191 187 193 187 193 26 D12S395 118672843 240 224 240 224 236 244 236 244 228 236 240 224 236 248 236 248 240 244 240 240 248 236 Supplementary File 1C: Affected cousin-pairs 8 9 10 11 HELLP_9147 HELLP_93130 HELLP_94126 HELLP_93113 8 9 12 13 12 13 8 9 8 9 12 13 14 15 12 8 9 13 / # Marker Position PIH PIH PIH PE PIH PIH PIH + IUGR 1 D12S309 94989229 146 146 136 136 136 146 146 146 140 140 140 136 2 D12S1716 95469203 203 203 207 209 207 205 203 205 205 205 207 205 3 D12S1300 97025042 119 127 119 127 123 119 119 123 123 127 119 119 4 D12S1063 97223531 224 211 207 207 211 207 207 211 211 207 5 D12S306 99116489 218 204 216 218 222 224 6 D12S1041 99982385 146 155 143 149 140 149 146 146 146 149 7 D12S1727 100225071 171 173 173 171 179 171 171 173 179 171 8 D12S1607 100782813 137 155 155 137 151 151 137 137 137 137 137 137 139 139 137 137 161 137 151 137 139 151 151 139 151 139 151 151 151 155 9 D12S1030 101448930 251 251 255 255 259 259 255 255 251 251 251 251 247 251 251 10 PAH 101789858 245 245 245 245 241 241 245 245 245 237 241 245 11 D12S360 102603188 213 217 209 213 213 217 213 213 213 213 219 213 221 213 213 209 213 213 215 213 213 217 213 217 213 217 213 215 213 221 12 D12S338