Thanatophoric dysplasia
Encyclopedia
Thanatophoric dysplasia is a severe skeletal
disorder characterized by extremely short limbs and folds of extra skin on the arms and legs.
, small ribs, underdeveloped lung
s, and an enlarged head with a large forehead
and prominent, wide-spaced eyes.
Thanatophoric dysplasia is a lethal skeletal dysplasia divided into two subtypes. Type I is characterized by extreme rhizomelia, bowed long bones, narrow thorax, a relatively large head, normal trunk length and absent cloverleaf skull. The spine shows platyspondyly, the cranium has a short base, and, frequently, the foramen magnum is decreased in size. The forehead is prominent, and hypertelorism and a saddle nose may be present. Hands and feet are normal, but fingers are short. Type II is characterized by short, straight long bones and cloverleaf skull.
(platyspondyly) and shortened thoracic ribs. Note: Prenatal ultra-sound images of the ribs sometimes appear asymmetrical when in fact they are not. In certain cases, this has caused a misdiagnosis of Osteogenisis Imperfecta (OI) type II.
An unusual head shape called kleeblattschädel ("cloverleaf skull") can be seen with type 2 thanatophoric dysplasia.
for "death bearing". Children with this condition are usually stillborn or die shortly after birth from respiratory failure. The survivors have difficulty breathing on their own and require respiratory support such as high flow oxygen through a canula or ventilator support via tracheostomy. There may also be evidence of spinal stenosis and brain seizures.
The oldest current known TD survivor is a 23-year old male. Another male lived to age 20. Two children with TD aged 8 and 10, a male and a female, are known in Germany. There is also a 5-year old male living with TD who is able to spend several hours off ventilator support.
Skeleton
The skeleton is the body part that forms the supporting structure of an organism. There are two different skeletal types: the exoskeleton, which is the stable outer shell of an organism, and the endoskeleton, which forms the support structure inside the body.In a figurative sense, skeleton can...
disorder characterized by extremely short limbs and folds of extra skin on the arms and legs.
Symptoms
Infants with this condition have disproportionately short arms and legs with extra folds of skin. Other signs of the disorder include a narrow chestChest
The chest is a part of the anatomy of humans and various other animals. It is sometimes referred to as the thorax or the bosom.-Chest anatomy - Humans and other hominids:...
, small ribs, underdeveloped lung
Lung
The lung is the essential respiration organ in many air-breathing animals, including most tetrapods, a few fish and a few snails. In mammals and the more complex life forms, the two lungs are located near the backbone on either side of the heart...
s, and an enlarged head with a large forehead
Forehead
For the Arsenal striker see GervinhoIn human anatomy, the forehead is the fore part of the head. It is, formally, an area of the head bounded by three features, two of the skull and one of the scalp. The top of the forehead is marked by the hairline, the edge of the area where hair on the scalp...
and prominent, wide-spaced eyes.
Thanatophoric dysplasia is a lethal skeletal dysplasia divided into two subtypes. Type I is characterized by extreme rhizomelia, bowed long bones, narrow thorax, a relatively large head, normal trunk length and absent cloverleaf skull. The spine shows platyspondyly, the cranium has a short base, and, frequently, the foramen magnum is decreased in size. The forehead is prominent, and hypertelorism and a saddle nose may be present. Hands and feet are normal, but fingers are short. Type II is characterized by short, straight long bones and cloverleaf skull.
Classification
Infants with type 1 thanatophoric dysplasia also have curved thigh bones, flattened bones of the spineVertebral column
In human anatomy, the vertebral column is a column usually consisting of 24 articulating vertebrae, and 9 fused vertebrae in the sacrum and the coccyx. It is situated in the dorsal aspect of the torso, separated by intervertebral discs...
(platyspondyly) and shortened thoracic ribs. Note: Prenatal ultra-sound images of the ribs sometimes appear asymmetrical when in fact they are not. In certain cases, this has caused a misdiagnosis of Osteogenisis Imperfecta (OI) type II.
An unusual head shape called kleeblattschädel ("cloverleaf skull") can be seen with type 2 thanatophoric dysplasia.
Prognosis
The term thanatophoric is GreekGreek language
Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...
for "death bearing". Children with this condition are usually stillborn or die shortly after birth from respiratory failure. The survivors have difficulty breathing on their own and require respiratory support such as high flow oxygen through a canula or ventilator support via tracheostomy. There may also be evidence of spinal stenosis and brain seizures.
The oldest current known TD survivor is a 23-year old male. Another male lived to age 20. Two children with TD aged 8 and 10, a male and a female, are known in Germany. There is also a 5-year old male living with TD who is able to spend several hours off ventilator support.