Dwarfism (Achondroplasia)

A genetic disorder of bone growth, achondroplasia is the most common cause of short stature with disproportionately short limbs -- dwarfism with short arms and legs. There is a typically large head with prominence of the forehead (frontal bossing), underdevelopment (hypoplasia) of the midface with cheekbones that lack prominence, and a low nasal bridge with narrow nasal passages. The fingers are short and the ring and middle fingers diverge giving the hand a trident (three-pronged) appearance.

SYMPTOMS

• An average-size trunk
• Short arms and legs, with particularly short upper arms and upper legs
• Short fingers, often with a wide separation between the middle and ring fingers
• Limited mobility at the elbows
• A disproportionately large head, with a prominent forehead and a flattened bridge of the nose
• Progressive development of bowed legs
• Progressive development of swayed lower back
• An adult height around 4 feet (122 cm)

CAUSES

• An average-size trunk
• Short arms and legs, with particularly short upper arms and upper legs
• Short fingers, often with a wide separation between the middle and ring fingers
• Limited mobility at the elbows
• A disproportionately large head, with a prominent forehead and a flattened bridge of the nose
• Progressive development of bowed legs
• Progressive development of swayed lower back
• An adult height around 4 feet (122 cm)