Alazami syndrome: the first case of papillary thyroid carcinoma

J Hum Genet. 2020 Jan;65(2):133-141. doi: 10.1038/s10038-019-0682-5. Epub 2019 Oct 28.

Abstract

Alazami syndrome (MIM#615071) is a rare developmental disorder caused by biallelic variants in the LARP7 gene. Hallmark features include short stature, global developmental delay, and distinctive facial features. To date, 23 patients from 11 families have been reported in the literature. Here we describe a 19-year-old man who, in association with the typical features of Alazami syndrome, was diagnosed at the age of 14 years with papillary thyroid carcinoma, harboring the somatic BRAF V600E mutation. Whole exome sequencing revealed two novel LARP7 variants in compound heterozygosity, whereas only common variants were detected in genes associated with familial nonmedullary thyroid cancer (MIM#188550). LARP7 acts as a tumor suppressor in breast and gastric cancer, and possibly, according to recent studies, in thyroid tumors. Since thyroid cancer is rare among children and adolescents, we hypothesize that the LARP7 variants identified in our patient are responsible for both Alazami syndrome and tumor susceptibility. We also provide an overview of the clinical findings in all Alazami syndrome patients reported to date and discuss the possible pathogenetic mechanism that may underlie this condition, including the role of LARP7 in tumor susceptibility.

Publication types

  • Case Reports

MeSH terms

  • Developmental Disabilities / genetics*
  • Dwarfism / genetics*
  • Exome Sequencing
  • Frameshift Mutation
  • Genetic Predisposition to Disease
  • Heterozygote
  • Humans
  • Intellectual Disability / genetics*
  • Italy
  • Male
  • Phenotype
  • Proto-Oncogene Proteins B-raf / genetics*
  • Ribonucleoproteins / genetics*
  • Thyroid Cancer, Papillary / diagnostic imaging
  • Thyroid Cancer, Papillary / genetics*
  • Thyroid Cancer, Papillary / pathology
  • Thyroid Neoplasms / diagnostic imaging
  • Thyroid Neoplasms / genetics*
  • Thyroid Neoplasms / pathology
  • Young Adult

Substances

  • Larp7 protein, human
  • Ribonucleoproteins
  • BRAF protein, human
  • Proto-Oncogene Proteins B-raf