CAUSES OF CONGENITAL HYPOTHYROIDISM

• Thyroid agenesis or dysgenesis
• Ectopic thyroid gland
• Defective synthesis
• TRH deficiency or insensitivity
• TSH deficiency or insensitivity
• Transplacental passage of antithyroid drug
• Peripheral resistance to thyroid hormone.
• Maternal ingestion of goitrogens.
  
  

CLINICAL MANIFESTATIONS :

The clinical manifestations depend on the functional state of the thyroid. They are generally absent at birth and appear gradually over about 6 weeks.

Early manifestations :

• Lethargy
• Poor feeding
• Inactivity
• Respiratory distress
• Hypotonia
• Large anterior and posterior fontanelles
• Pallor
• Peripheral cyanosis
• Hoarse cry
• Constipation
• Hypothermia
• Prolonged physiologic jaundice

Late manifestations :

• Depressed nasal bridge
• Narrow forehead
• Puffy eyelids
• Thick, dry and coarse skin
• Coarse hair
• Large tongue
• Abdominal distension
• Umbilical hernia
• Poor reflexes
• Bradycardia
• Hypotension
• Potbelly
• Diminished pulse pressure
• Anemia not responding to iron
• Sensorineural hearing loss
• Slipped capital femoral epiphysis can occur
• Kocher-Debre-Semelaign syndrome, which consists of generalized muscular hypertrophy giving the child a "Herculean" appearance.
• Growth retardation
• Mental retardation
• Delayed sexual maturation

Ancillary laboratory manifestations :

• Delayed bone age
• Epiphyseal dysgenesis
• Low complexes in the EEG and ECG
• Cardiomegaly on X-ray chest indicating myxedema
• Enlargement of sella turcica

Last created on 23-02-2001
Last updated on 01-07-2006