title: FOXE1 polyalanine tract length polymorphism in patients with thyroid hemiagenesis and subjects with normal thyroid.
abstract: OBJECTIVE
  Recent studies have pointed to the correlation between FOXE1 polyalanine tract (FOXE1-polyAla) length polymorphism and genetic susceptibility to thyroid dysgenesis causing congenital hypothyroidism. The objective of this study was a first assessment of the role of FOXE1-polyAla expansion in the genetic background of thyroid hemiagenesis (TH).
  
  
  METHODS
  The group studied consisted of 40 patients with TH, including 6 familial cases and a control group of 89 subjects with a normal thyroid. The polyAla tract and flanking sequence of FOXE1 was amplified using conventional PCR. Subsequently, capillary electrophoresis was performed to estimate the length of products.
  
  
  RESULTS
  A short variant of FOXE1-polyAla, containing 12 alanines, was present in 5 control subjects (5.6%), but was not found in TH. The incidence of longer variants (≥16 codons) of FOXE1-polyAla was significantly higher in patients with the familial form of TH in comparison to those with sporadic TH (p = 0.003) and controls (p = 0.005).
  
  
  CONCLUSIONS
  There is high polymorphic variability of FOXE1-polyAla in both groups. Shorter variants of FOXE1-polyAla are underrepresented in subjects with familial TH. Therefore, FOXE1-polyAla tract expansion may contribute to the molecular background of familial but not sporadic forms of TH. Further studies are still required to confirm such findings.
authors.affiliation: Department of Endocrinology, Metabolism and Internal Medicine, Poznan University of Medical Sciences, Poznan, Poland.
authors.forename: Ewelina
authors.initials: E
authors.lastname: Szczepanek
authors.forename: Marek
authors.initials: M
authors.lastname: Ruchala
authors.forename: Witold
authors.initials: W
authors.lastname: Szaflarski
authors.forename: Bartlomiej
authors.initials: B
authors.lastname: Budny
authors.forename: Lidia
authors.initials: L
authors.lastname: Kilinska
authors.forename: Malgorzata
authors.initials: M
authors.lastname: Jaroniec
authors.forename: Marek
authors.initials: M
authors.lastname: Niedziela
authors.forename: Maciej
authors.initials: M
authors.lastname: Zabel
authors.forename: Jerzy
authors.initials: J
authors.lastname: Sowinski
mesh_terms: D001483:Base Sequence; D016022:Case-Control Studies; D003409:Congenital Hypothyroidism / Q000235:genetics; D042622:DNA Repeat Expansion / Q000235:genetics; D005190:Family; D005260:Female; D051858:Forkhead Transcription Factors / Q000235:genetics*; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D010455:Peptides / Q000235:genetics*; D011110:Polymorphism, Genetic; D050033:Thyroid Dysgenesis / Q000235:genetics*; D013961:Thyroid Gland / Q000502:physiology
chemical_list: C106894:FOXE1 protein, human; D051858:Forkhead Transcription Factors; D010455:Peptides; C019529:polyalanine