Primary Congenital Hypothyroidism: Clinical Characteristics and Etiological Study
Kevalee Unachak MD*, Prapai Dejkhamron MD*
Affiliation : * Department of Pediatrics, Faculty of Medicine, Chiang Mai University
Forty-eight children with primary congenital hypothyroidism, who attended Chiang Mai
University Hospital, during 1977-2000, were reviewed. The female to male ratio was 2:1. The age at
diagnosis ranged from 1 month to 12 years 4 months, with 27% of the cases diagnosed within the first
three months of life, 37.5% within the first year, and 62.5% after one year of age. Constipation, delayed
development and growth, feeding problems, prolonged neonatal jaundice and goiter were more common.
Prolonged neonatal jaundice was found in every case diagnosed within the first three months. The other
common signs were dry or mottled skin, abdominal distension, macroglossia, short stature, puffy face and
umbilical hernia.
Kocher-Debr(cid:31)-Semelaigne syndrome comprised 18.7% of cases with a 2:1 female to male ratio, and
it was found in various forms of hypothyroidism. Thyroid scintigrams were done in 47 patients. Thyroid
dysgenesis was the most common etiology (80.9%), which consisted of 40.4% athyreosis, 4.3% hypoplasia,
and 36.2% thyroid ectopy. Thyroid dyshormonogenesis accounted for 18.9%, in which only 4 of 9 presented
with goiter. Two-thirds of these patients showed a positive result to the perchlorate discharge test, indicating
an organification defect. All patients had elevated serum TSH level greater than 50 mU/L. The serum T4 level
below 2 µg/dL was observed in 17 of 19 patients with athyreosis, 11 of 17 with thyroid ectopy, and 6 of 9 with
thyroid dyshormonogenesis. These findings including retarded bone age were unable to differentiate among
different groups of hypothyroidism.
Keywords : Primary congenital hypothyroidism, Kocher-Debr(cid:31)-Semelaigne syndrome, Thyroid dysgenesis, Athyreosis, Thyroid ectopy, Thyroid dyshormonogenesis,
