Permanent and transient congenital hypothyroidism in Isfahan-Iran.
OBJECTIVE
To determine the prevalence of permanent and transient congenital hypothyroidism (CH) in Isfahan, Iran.


METHODS
In 256 primarily diagnosed CH patients identified through the neonatal screening programme from May 2002 to February 2005, treatment was discontinued for 4 weeks and T4 and thyroid stimulating hormone (TSH) were measured. Permanent or transient CH was determined from the results of the thyroid function tests and the radiologic findings. Patients with TSH levels >6 (mIU/l) were diagnosed with permanent CH.


RESULTS
Results were available from 204 patients, of whom 122 patients were diagnosed with permanent CH (59.8%) (prevalence 1:748 births), and 82 with transient hypothyroidism (prevalence 1:1114). Permanent CH was associated with higher initial TSH levels than transient hypothyroidism (P < 0.05). The most common aetiology of CH was dyshormonogenesis.


CONCLUSIONS
The rates of both permanent and transient CH in our study were higher than the comparable worldwide rates. The transient group had low T4 levels, suggesting that iodine contamination should be investigated. The aetiology of CH was also different from that recorded in many other studies.
Hashemipour
Mahin
M
Endocrinology, Endocrine & Metabolism Research Center, Isfahan University of Medical Sciences, Sedigheh Tahereh Medical Research Complex, Khorram Street, Jomhouri Square, Isfahan 8187698191, Iran. hashemipour@med.mui.ac.ir
Hovsepian
Silva
S
Kelishadi
Roya
R
Iranpour
Ramin
R
Hadian
Rezvane
R
Haghighi
Sassan
S
Gharapetian
Angineh
A
Talaei
Mojtaba
M
Amini
Massoud
M
D003409:Congenital Hypothyroidism / Q000175:diagnosis* / Q000453:epidemiology* / Q000209:etiology; D005260:Female; D006801:Humans; D007037:Hypothyroidism / Q000175:diagnosis / Q000453:epidemiology* / Q000209:etiology; D007231:Infant, Newborn; D007492:Iran / Q000453:epidemiology; D008297:Male; D015997:Neonatal Screening; D013960:Thyroid Function Tests