Alagille syndrome in a Vietnamese cohort: Mutation analysis and assessment of facial features

Henry C. Lin, Phuc Le Hoang, Anne Hutchinson, Grace Chao, Jennifer Gerfen, Kathleen M. Loomes, Ian Krantz, Binita M. Kamath, Nancy B. Spinner

Research output: Contribution to journalArticle

12 Scopus citations

Abstract

Alagille syndrome (ALGS, OMIM #118450) is an autosomal dominant disorder that affects multiple organ systems including the liver, heart, eyes, vertebrae, and face. ALGS is caused by mutations in one of two genes in the Notch Signaling Pathway, Jagged1 (JAG1) or NOTCH2. In this study, analysis of 21 Vietnamese ALGS individuals led to the identification of 19 different mutations (18 JAG1 and 1 NOTCH2), 17 of which are novel, including the third reported NOTCH2 mutation in Alagille Syndrome. The spectrum of JAG1 mutations in the Vietnamese patients is similar to that previously reported, including nine frameshift, three missense, two splice site, one nonsense, two whole gene, and one partial gene deletion. The missense mutations are all likely to be disease causing, as two are loss of cysteines (C22R and C78G) and the third creates a cryptic splice site in exon 9 (G386R). No correlation between genotype and phenotype was observed. Assessment of clinical phenotype revealed that skeletal manifestations occur with a higher frequency than in previously reported Alagille cohorts. Facial features were difficult to assess and a Vietnamese pediatric gastroenterologist was only able to identify the facial phenotype in 61% of the cohort. To assess the agreement among North American dysmorphologists at detecting the presence of ALGS facial features in the Vietnamese patients, 37 clinical dysmorphologists evaluated a photographic panel of 20 Vietnamese children with and without ALGS. The dysmorphologists were unable to identify the individuals with ALGS in the majority of cases, suggesting that evaluation of facial features should not be used in the diagnosis of ALGS in this population. This is the first report of mutations and phenotypic spectrum of ALGS in a Vietnamese population.

Original languageEnglish (US)
Pages (from-to)1005-1013
Number of pages9
JournalAmerican Journal of Medical Genetics, Part A
Volume158 A
Issue number5
DOIs
StatePublished - May 1 2012

Keywords

  • Alagille syndrome
  • JAGGED1
  • JAGGED1 missense mutation
  • NOTCH2

ASJC Scopus subject areas

  • Genetics
  • Genetics(clinical)

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    Lin, H. C., Le Hoang, P., Hutchinson, A., Chao, G., Gerfen, J., Loomes, K. M., Krantz, I., Kamath, B. M., & Spinner, N. B. (2012). Alagille syndrome in a Vietnamese cohort: Mutation analysis and assessment of facial features. American Journal of Medical Genetics, Part A, 158 A(5), 1005-1013. https://doi.org/10.1002/ajmg.a.35255