title: [Growth hormone deficiency, hypothyroidism and ring chromosome 18: case report].
abstract: BACKGROUND
  The association of 18-ring chromosome syndrome and growth hormone deficiency (GHD) is extremely rare, with only two reports in the literature.
  
  
  METHODS
  A one year-old, non-white female was referred due to hypoglycemic seizures. She had developmental delay and poor nutrition. Her physical examination was significant for a weight Z score of -6.95, height Z score of -5,05, cleft palate, epicanthic folds and generalized hypotony. Karyotype was 46XX r(18) (p11,2- q.23)--18 ring chromosome syndrome, the MRI showed an ectopic neurohypophysis. The diagnosis GHD was made due to low GH levels during spontaneous severe hypoglycemia at the age of 16 months. She was started on hGH 0.1 U/kg/day. Three months later, TSH deficiency was diagnosed and L-thyroxin therapy was started. During hGH replacement the hypoglycemic events stopped but after 3 years of hGH therapy, she did not improve growth velocity.
  
  
  CONCLUSIONS
  We were unable to find any report of GHD and hypothyroidism associated with the 18-ring chromosome syndrome. Children with 18-ring chromosome should undergo investigation of GHD. In our child with 18-ring syndrome the hGH therapy did not improve growth velocity.
authors.affiliation: Servico de Endocrinologia Pediatrica, Instituto de Puericultura e Pediatria Martagao Gesteira, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ.
authors.forename: Juliana V
authors.initials: JV
authors.lastname: Thomas
authors.forename: Daniela F C
authors.initials: DF
authors.lastname: Mezzasalma
authors.forename: Andreza M
authors.initials: AM
authors.lastname: Teixeira
authors.forename: Ludmila N R
authors.initials: LN
authors.lastname: Campos
authors.forename: Jorge Luiz
authors.initials: JL
authors.lastname: Luescher
authors.forename: Izabel C R
authors.initials: IC
authors.lastname: Beserra
authors.forename: Marilia M
authors.initials: MM
authors.lastname: Guimarães
mesh_terms: D002887:Chromosomes, Human, Pair 18 / Q000235:genetics*; D005260:Female; D019382:Human Growth Hormone / Q000172:deficiency*; D006801:Humans; D007037:Hypothyroidism / Q000175:diagnosis* / Q000188:drug therapy; D007223:Infant; D007231:Infant, Newborn; D007234:Infant, Premature; D012303:Ring Chromosomes; D013974:Thyroxine / Q000627:therapeutic use
chemical_list: D019382:Human Growth Hormone; D013974:Thyroxine