The child with hypopituitarism is usually of normal size and weight at birth although those with MPHD and genetic defects of the GH1 or GHR gene have birth lengths that average 1 SD below the mean. Children with severe defects in GH production or action are more than 4 SD below the mean by 1 yr of age. Those with less severe deficiencies grow at rates below the 25% for age and gradually diverge from normal height percentiles. Delayed closure of the epiphyses permits growth beyond the normal age when growth should be complete.
Infants with congenital defects of the pituitary or hypothalamus usually present with neonatal emergencies such as apnea, cyanosis, or severe hypoglycemia with or without seizures.
Microphallus in boys provides an additional diagnostic clue.
Deficiency of GH may be accompanied by hypoadrenalism and hypothyroidism.
Prolonged neonatal jaundice is common. It involves elevation of conjugated and unconjugated bilirubin and may be mistaken for neonatal hepatitis.
The head in the toddler is round, and the face is short and broad. The frontal bone is prominent, and the bridge of the nose is depressed and saddle-shaped. The nose is small, and the nasolabial folds are well developed. The eyes are somewhat bulging. The mandible and the chin are underdeveloped, and the teeth, which erupt late, are frequently crowded. The neck is short, and the larynx is small. The voice is high-pitched and remains high after puberty. The extremities are well proportioned, with small hands and feet. Weight for height is usually normal, but an excess of body fat and a deficiency of muscle mass contributes to a pudgy appearance.
The genitals are usually small for age, and sexual maturation may be delayed or absent. Facial, axillary, and pubic hair usually is lacking, and the scalp hair is fine.
Mainly length is affected, giving toddlers a pudgy appearance. Symptomatic hypoglycemia, usually after fasting, occurs in 10–15% of children with panhypopituitarism and those with IGHD.
Intelligence is usually normal.