Dwarfism

Dwarfism is a medical or genetic condition of short stature. The average height of an adult with dwarfism is 4 feet. There are two main types of dwarfism: disproportionate and proportionate. Disproportionate dwarfism is characterized by an average-size torso and shorter arms and legs or a shortened trunk with longer limbs. In proportionate dwarfism, the body parts are in proportion but shortened. 

Causes

There are more than 200 conditions that may cause dwarfism. Causes of proportionate dwarfism include metabolic and hormonal disorders (like hormone growth deficiency).

Skeletal dysplasias,the most common types of dwarfism, are genetic. They are conditions of abnormal bone growth that cause disproportionate dwarfism.  

They include:

Achondroplasia. This is the most common form of dwarfism, and is evident at birth. Achondroplasia occurs in about one out of 26,000 to 40,000 babies. People with this condition have a long trunk and shortened upper arms and upper legs. Other features of achondroplasia include:

• a large head with a prominent forehead
• a flattened nose bridge
• protruding jaw
• crowded and crooked teeth
• lower spine curved forward
• bowed legs
• short, flat, broad feet
• double-jointed

Spondyloepiphyseal dysplasias (SED). Is a less common form of dwarfism. It affects approximately one in 95,000 babies. SED is a group of conditions that cause a shortened trunk (which may no-show until a child is between 5 and 10 years old). Other features can include:

• club feet
• cleft palate
• severe hip osteoarthritis
• weak hands and feet
• barrel-chested appearance

Diastrophic dysplasia. A rare form of dwarfism, diastrophic dysplasia occurs in about one in 100,000 births. People who have it tend to have mesomelic shortening, which means they have shortened forearms and calves.

Other signs can include:

• deformed hands and feet
• limited range of motion
• cleft palate
• cauliflower appearance of the ears   

Dwarfism Genetics

Skeletal dysplasia is caused by a genetic mutation that can be spontaneous or inherited.

Diastrophic dysplasia and spondyloepiphyseal dysplasias are inherited in a recessive manner (child must receive a copy of the mutated gene from the mother, and a copy from the father to be affected).  

Achondroplasia is inherited in a dominant manner (only needs one copy). There is a 25% chance that a child born to a couple in which both members have achondroplasia will be of normal height. But there is also a 25% chance the child will inherit both dwarfism genes (double-dominant syndrome). This is a fatal condition that usually results in a miscarrige. 

Many times, parents of children with achondroplasia do not carry the mutated gene; the mutation occurs randomly during conception.

Diagnosis
 Dwarfism of any of there types can be diagnosed through genetic testing. Sometimes, prenatal testing is done if there is concern for certain conditions.

Some signs/ symptoms are:

• late development of some motor skills, like sitting or walking

 ear infections

• breathing problems
• weight problems

spine curvature

• bowed legs
• joint stiffness and arthritis
• lower backpain or leg numbness
• teeth crowding

Dwarfism Treatments

Early diagnosis and treatment can help prevent some problems that come with dwarfism. People with dwarfism related to growth hormone deficiency can be treated with growth hormone. 

Other treatment may include:

• Physical therapy to stretch joints and strengthen muscles
• Back braces

Draining tubes in the middle ear.

• Orthodontic treatment to fix teeth crowding
• exercise

Many times, people with dwarfism have orthopaedic or medical complications, so they need more/other treatments.




 source: http://www.webmd.com/children/dwarfism-causes-treatments