<unk>  is often diagnosed in childhood on the basis of visible symptoms. A physical examination can usually suffice to diagnose certain types of<unk> , but genetic testing and diagnostic imaging may be used to determine the exact condition. In a person's youth, growth charts that track height can be used to diagnose subtle forms of<unk>  that have no other striking physical characteristics. Short stature or stunted growth during youth is usually what brings the condition to medical attention. Skeletal dysplasia is usually suspected because of obvious physical features (e.g., unusual configuration of face or shape of skull), because of an obviously affected parent, or because body measurements (arm span, upper to lower segment ratio) indicate disproportion. Bone X-rays are often key to diagnosing a specific skeletal dysplasia, but are not the sole diagnostic tool. Most children with suspected skeletal dysplasias are referred to a genetics clinic for diagnostic confirmation and genetic counseling. Since about the year 2000, genetic tests for some of the specific disorders have become available. During an initial medical evaluation of shortness, the absence of disproportion and other clues listed above usually indicates causes other than bone dysplasias. Classification Lavinia Warren, an actress with pituitary<unk>  (growth hormone deficiency) In men and women, the sole requirement for being considered a dwarf is having an adult height under and it is almost always sub-classified with respect to the underlying condition that is the cause of the short stature.<unk>  is usually caused by a genetic variant; achondroplasia is caused by a mutation on chromosome 4. If<unk>  is caused by a medical disorder, the person is referred to by the underlying diagnosed disorder. Disorders causing<unk>  are often classified by proportionality. Disproportionate<unk>  describes disorders that cause unusual proportions of the body parts, while proportionate<unk>  results in a generally uniform stunting of the body. Disorders that cause<unk>  may be classified according to one of hundreds of names, which are usually permutations of the following roots: * location * rhizomelic = root, i.e., bones of the upper arm or thigh * mesomelic = middle, i.e., bones of the forearm or lower leg * acromelic = end, i.e., bones of hands and feet. * micromelic = entire limbs are shortened * source * chondro = of cartilage * osteo = of bone * spondylo = of the vertebrae * plasia = form * trophy = growth Examples include achondroplasia and chondrodystrophy.
Dwarfism
Primordial dwarfism
Brachyphalangy
Parastremmatic dwarfism
Micrognathism
Renal hypoplasia
Iniencephaly
Renal agenesis