Achondroplasia is a genetic bone disorder classified under the group of disorders known as chondrodystrophies or osteochondrodystrophies. A bone and cartilage growth disorder, achondroplasia results in a condition called dwarfism. A person inherits achondroplasia as an autosomal dominant trait, which means that a child is likely to suffer from the condition, even if one of the parents has this disorder. When either of the parents have this disorder, chances of a child getting achondroplasia is about 50%. However, if both the parents suffer from achondroplasia, then the probability increases to 75%. Nevertheless, in most cases, this disorder appears as spontaneous mutations, which means two parents without achondroplasia can give birth to a baby with the condition. Take a look at the symptoms and signs of achondroplasia, in the following lines.
Signs Of Achondroplasia
- The most common symptom in people with achondroplasia is the short stature. The average height of an adult male is 131 centimeters (52 inches, or 4 feet 4 inches) and the average height of an adult female is 124 centimeters (49 inches, 4 feet 1 inch).
- Such people have short and thick arms and legs, with the upper arms and thighs being more shortened, than the forearms and lower legs.
- They have a larger skull than the normal size, with a prominent forehead and a flattened nasal bridge. The occurrence of an enlarged head could be due to the collection of fluid around the brain, known as hydrocephalus.
- Such people have delayed developmental milestones such as walking i.e., the child may start walking between 18 to 24 months, instead of the normal 12 months.
- A person with achondroplasia is likely to face several dental problems, such as crowing and misalignment of teeth. Since it is difficult to maintain oral hygiene, such people have higher chances of developing tooth decay.
- They have a condition called lordosis, also called “sway-back”, where the lower spine if curved inwards or forward, eventually leads to kyphosis, where a small hump develops near the shoulders in childhood, but disappears once the child starts walking.
- People with achondroplasia have small vertebral canals (back bones), due to insufficient growth of the vertebrae. This leads to spinal cord compression, during adolescence, resulting in weakness and numbness below the spine that can also result in loss of bowel and bladder control. Such people die in infancy or early childhood, during their sleep, due to compression of the upper spinal cord that interferes with the breathing center.
- Another common symptom of achondroplasia patients is the breathing problem where breathing stops or slows down for short periods (apnea).
- Such people are also likely to suffer from obesity, even after binging on a regular diet, due to their short stature.
- Appearance of bowed legs and recurrent ear infections (otitis media) are other signs of achondroplasia.
- They have typically short fingers. The ring finger and middle finger may diverge with an extra space giving the hand a three-pronged appearance, known as the ‘trident hand’.