Iranian Journal of Pediatrics
Tehran University of Medical Sciences Press
Vol. 21, No. 2, 2011, pp. 188-192
Bioline Code: pe11032
Full paper language: English
Document type: Research Article
Document available free of charge
Iranian Journal of Pediatrics, Vol. 21, No. 2, 2011, pp. 188-192
© Copyright 2011 Iran Journal of Pediatrics.
Does Congenital Hypothyroidism Have Different Etiologies in Iran?|
Karamizadeh, Zohre; Dalili, Setillia; Sanei-far, Heidyeh; Karamifard, Hamdollah; Mohammadi, Hamid & Amirhakimi, Gholamhossein
Objective: To determine the prevalence of congenital hypothyroidism (CH), permanent and transient CH.
Methods: From November 2006 to September 2007, 63031 newborns were screened by measuring serum TSH obtained by heel prick. The neonates who had a TSH=5mU/L were recalled for measurement of serum T4, thyroid stimulating hormone (TSH) and TSH receptor blocking antibodies (TRBAb) in venous samples. In 43 primarily diagnosed as cases of CH, treatment was discontinued at age 2-3 years for 4 weeks and T4 and TSH were measured again. Permanent or transient CH was determined from the results of these tests and radiologic evaluation.
Findings: The incidence of congenital hypothyroidism was found to be 1:1465 with a female to male ratio of 1.19:1. The most common clinical findings were prolonged jaundice (73%), large anterior fontanel (56%) and wide posterior fontanel (55%). In 43 patients with CH, prevalence of permanent and transient form of the disorder was 53.6% and 46.4% respectively. Permanent CH was associated with higher initial TSH level than transient hypothyroidism (P<0.001). The most common etiology of permanent CH was dyshormonogenesis (57%). TRBAb was found in 6.8% of the total 43 cases.
Conclusion: Congenital hypothyroidism in Iran may have different etiologies. Due to higher rate of transient CH than other similar researches, it is reasonable to follow these patients for a longer period to rule out the possibility of permanent hypothyroidism.
Congenital Hypothyroidism; TSH Receptor; Dyshormonogenesis; Thyroid Dysgenesis
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