Caudal Dysplasia Health Article

Signs and symptoms

In order to understand the signs and symptoms of caudal dysplasia, it is important to understand early embryonic development. Very early in pregnancy, the cells that will develop into the embryo are organized as a small round ball. These cells eventually separate into three distinct layers: the endoderm, the mesoderm, and the ectoderm. The endoderm can be thought of as the inside layer. Cells from the endoderm will eventually form into the lining of the digestive tract and the respiratory tract. The mesoderm can be thought of as the middle layer, and the cells of the mesoderm will eventually become the muscles, bones, kidney, heart, and blood vessels. The endoderm can be thought of as the outside layer. The cells of the endoderm will eventually become the skin, hair, nails, brain, and nervous system. Caudal dysplasia is the result of an early insult to the tissues of the mesoderm. Since the mesoderm is the tissue that forms the bones, muscles, kidneys, and other tissues, individuals with caudal dysplasia will have problems with these tissues. Any disruption of the development of the mesoderm will lead to disruption of the organs formed from this layer. Impaired glucose metabolism early in pregnancy can lead to an insult, which results in the infant having caudal dysplasia. However, since only 16–22% of mothers of infants with caudal dysplasia have diabetes, there must be other factors that also cause caudal dysplasia. These other factors are not well understood at this time.

Caudal dysplasia is a disorder with a wide spectrum of defects. Some individuals are very mildly affected and some are much more severely affected. Individuals with caudal dysplasia can have some or all of the signs and symptoms.

Spinal cord abnormalities in infants affected with caudal dysplasia include:

• missing or malformed sacrum
• abnormal vertebrae
• cerebellum agenesis
• hydrocephalus
• spina bifida
• scoliosis

Kidney abnormalities include:

• hydronephrosis
• renal failure
• agenesis of the kidney
• hypoplasia of the kidney

Gastrointestinal abnormalities include:

• imperforate anus
• malformed or rotated gut

Heart abnormalities include:

• atrial septal defect
• coarctation of the aorta
• stenosis of the pulmonary valve

Lower limb abnormalities include:

• clubfeet
• missing reflexes
• paralysis or numbness of the legs

Neurological abnormalities include:

• neurogenic bladder (impaired bladder control)
• neurogenic bowel (impaired bowel control)
• motor and sensory nerve abnormalities

Other abnormalities include:

• cleft lip/palate
• diaphragmatic hernia
• hypoplastic lungs
• low-set ears
• tracheo-eosophageal fistula (connection between the trachea and eosophagus)

Diagnosis

The diagnosis of caudal dysplasia can be made during pregnancy, at birth, and during childhood, depending on the severity of the defects present.

Prenatal diagnosis

The diagnosis of caudal dysplasia can be made prenatally (during pregnancy) by prenatal ultrasound (a sonogram). Sonograms use sound waves to provide an image of a fetus. The structural abnormalities of caudal dysplasia, including absence of vertebra, kidney malformations, other spinal cord malformations, and limb abnormalities, can be seen during the second trimester of pregnancy. Because the bones of the sacrum do not ossify, or harden, until approximately 22 weeks of pregnancy, it may be difficult to diagnose caudal dysplasia before this time.

The diagnosis of caudal dysplasia can also be made by physical examination after birth. Physical signs can include flattening of the buttocks, shortening of the gluteal cleft, scoliosis, spina bifida, and hydrocephalus. X rays should be taken to look at the formation of the underlying bones and tissues.

Pregnancy management

When caudal dysplasia is diagnosed by prenatal ultrasound, the mother should be tested for diabetes. Pregnancy termination may be an option. If the pregnancy continues, the parents may wish to consult with specialists to get more specific information about prognosis.