AA, African American; ALGS, Alagille syndrome; Alagille syndrome; CEU, Utah Residents with Northern and Western European Ancestry; CHB, Han Chinese in Beijing, China; CI, confidence interval; DHPLC, Denaturing high performance liquid chromatography; DSL, Delta-Serrate-Lag2 domain; EA, European American; ESP, Exome Sequencing Project; HGMD, The Human Gene Mutation Database; HWE, Hardy­Weinberg Equilibrium; JAG1 mutations; JAG1, Gene coding for JAGGED1 protein; JPT, Japanese in Tokyo, Japan; LOVD, Leiden Open Variation Database; MAF, minor allele frequency; MEX, Mexican population; MIM, Mendelian Inheritance in Man; Mexican patients; NA, not applicable; ND, not determined; NMD, Nonsense Mediated mRNA Decay; NOTCH2, gene coding for NOTCH2 protein; OR, odds ratio; PCR, polymerase chain reaction; YRI, Yoruba in Ibadan, Nigeria; dbSNP, The Single Nucleotide Polymorphism Database; kb, kilobase(s) or 1000 bp; mutDB, mutDB Polymorphism Database