1. CONGENITAL HYPOTHYROIDISM General Hospital of Tianjing Medicine University

4. Introduction Congenital hypothyroidism results from deficient production of thyroid hormone or a defect of thyroid hormonal receptor activity. The disorder may be manifested from birth. The major clinical characteristics of congenital hypothyroidism are retardation in growth and mental development.

6. Etiology

15. Regulation of thyroid function The thyroid is regulated by thyroid-stimulating hormone (TSH) which is secreted by the anterior pituitary. TSH synthesis and release are stimulated by TSH –releasing hormone (TRH), which is synthesized in the hypothalamus and secreted into the hypophyseal portal which enters the pituitary. In a state of decreased production of thyroid hormone, TSH and TRH are increased. Exogenous thyroid hormone or increased thyroid hormone synthesis causing elevated blood levels inhibits TSH and TRH production. This is called negative feedback. (see Fig)

18. Metabolism promotes heat production increases glucose absorption Increases blood cholesterol accelerates both synthesis and degradation of protein.

24. Umbilical hernia

28. short stature

31. Coarse facial features

33. Filter blood spots (blood of heel )

35. radionuclide scans Normal thyroid

36. Thyriod under tongue and displasia

39. mental is normal. Bone age is normal. Skeletal X –ray No characteristic facies Serum levels of T4 and TSH are normal. Rickets

40. Down `s syndrome Chromosome abnormality Mental retardation No myxedema Characteristic facies.

41. Pituitary dwarfism (Growth hormone deficiency ) Short stature Bone age is delayed Intelligence is usually normal No characteristic facies or physiological hypofunction.

42. Congenital giant colon Distention and constipation no other manifestation of congenital hypothyroidism

47. An infant of 6 mo. A before treatment B four mo after treatment