title: Diagnosis of chromosomal abnormalities in a patient with thanatophoric dysplasia (TD) type I: The first report describing an important association between cytogenetic findings and TD.
abstract: BACKGROUND
  Thanatophoric dysplasia (TD) is the most lethal and most severe type of dysplasia. It has distinct features, the most important of which is short tubular bones and short ribs with platyspondyly, allowing a precise radiologic and prenatal ultrasonographic diagnosis. It has been reported to be caused by mutations in the FGFR3 gene, but exactly how cytogenetic abnormalities might lead to TD is unclear.
  
  
  METHODS
  We report a case of TD with different prenatal sonographic features compatible with the classification of type I. In the result of cytogenetic examination, we found de novo CAs in 28% of cells analyzed from the affected infant; 75% of the abnormalities were numerical, and of those, 25% were structural aberrations; 21% of cells revealed predominantly numerical aberrations. Monosomy 18, 21 and 22 was observed in 4% of cells, monosomy 20 in 2%, and monosomy 7, 8, 14, 17 and 19 in 1%. Structural changes were observed in 7% of cells.
  
  
  CONCLUSIONS
  It appears that these chromosomes may be preferentially involved in and important for TD development.
authors.affiliation: Department of Pediatrics, Faculty of Medicine, Adıyaman University, Adiyaman, Turkey.
authors.forename: Mehmet
authors.initials: M
authors.lastname: Turgut
authors.forename: Osman
authors.initials: O
authors.lastname: Demirhan
authors.forename: Erdal
authors.initials: E
authors.lastname: Tunc
authors.forename: Ibrahim Hakan
authors.initials: IH
authors.lastname: Bucak
authors.forename: Perihan Yasemen
authors.initials: PY
authors.lastname: Canoz
authors.forename: Fatih
authors.initials: F
authors.lastname: Temiz
authors.forename: Gokhan
authors.initials: G
authors.lastname: Tumgor
keywords: chromosomal aberrations; monosomy; thanatophoric dysplasia; type I