title: Squamosal Suture Craniosynostosis Due to Hyperthyroidism Caused by an Activating Thyrotropin Receptor Mutation (T632I).
abstract: BACKGROUND
  Congenital hyperthyroidism can be a cause of failure to thrive, hyperactivity, developmental delay, and craniosynostosis during infancy. Most commonly, the condition occurs in the setting of maternal autoimmune thyroid disease. Rarely, congenital hyperthyroidism can also occur secondary to activating mutations within the thyrotropin (TSH) receptor.
  
  
  METHODS
  A Hispanic male infant presented at age 6 months with severe thyrotoxicosis. At the time of presentation he was being evaluated for squamosal suture synostosis and he was noted to have significant developmental delays.
  
  
  CONCLUSIONS
  The patient's thyrotoxicosis was initially treated with antithyroid medication, and he subsequently underwent craniosynostosis repair leading to neurodevelopmental improvement. DNA from the patient and his parents was submitted for mutational analysis of exons 9 and 10 of the TSH receptor. He was found to carry a monoallelic transition 1895C>T in exon 10 that resulted in the substitution of threonine at position 632 by isoleucine (T32I). This mutation resulted in constitutive activation of the TSH receptor. Neither parent carried this mutation indicating that the child has acquired a de novo germline mutation.
  
  
  CONCLUSIONS
  We report the first case of squamosal suture craniosynostosis in a patient with non-autoimmune hyperthyroidism. Squamosal suture craniosynotosis is rare, often has a subtle presentation, and should be considered in all patients with this condition because prompt treatment of hyperthyroidism and craniosynotosis repair can lead to normalization of neurodevelopment.
authors.affiliation: 1 Division of Pediatric Endocrinology, Phoenix Children's Hospital , Phoenix, Arizona.
authors.forename: Reeti
authors.initials: R
authors.lastname: Chawla
authors.affiliation: 2 Division of Neurosurgery, Ann and Robert H. Lurie Children's Hospital of Chicago , Northwestern University Feinberg School of Medicine, Chicago, Illinois.
authors.forename: Tord D
authors.initials: TD
authors.lastname: Alden
authors.affiliation: 3 Department of Biology, Harold Washington College , Chicago, Illinois.
authors.forename: Aigerim
authors.initials: A
authors.lastname: Bizhanova
authors.affiliation: 4 Division of Pediatric Endocrinology, Ann and Robert H. Lurie Children's Hospital of Chicago , Northwestern University Feinberg School of Medicine, Chicago, Illinois.
authors.forename: Rachel
authors.initials: R
authors.lastname: Kadakia
authors.affiliation: 4 Division of Pediatric Endocrinology, Ann and Robert H. Lurie Children's Hospital of Chicago , Northwestern University Feinberg School of Medicine, Chicago, Illinois.
authors.forename: Wendy
authors.initials: W
authors.lastname: Brickman
authors.affiliation: 5 Division of Endocrinology Metabolism and Molecular Medicine, Northwestern University Feinberg School of Medicine , Chicago, Illinois.
authors.forename: Peter A
authors.initials: PA
authors.lastname: Kopp
mesh_terms: D002675:Child, Preschool; D003398:Craniosynostoses / Q000235:genetics*; D004252:DNA Mutational Analysis; D006801:Humans; D006980:Hyperthyroidism / Q000235:genetics*; D007223:Infant; D008297:Male; D009154:Mutation; D011989:Receptors, Thyrotropin / Q000235:genetics*
chemical_list: D011989:Receptors, Thyrotropin