Idiopathic infantile arterial calcification
Idiopathic infantile arterial calcification is a rare genetic condition affecting the circulatory system that does not typically have a good prognosis. It is a condition characterized by the calcification of minerals in an infant's arteries. It is also called generalized arterial calcification of infancy (GACI).
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Definition & Facts
Idiopathic infantile arterial calcification involves calcification that is generally spread all over the body. It affects the blood vessel walls of the arteries that transport blood away from the heart to the rest of the body. This means the circulatory system cannot get enough blood to each of the body's most vital organs.
Doctors believe this condition occurs when the ENPP1 (Ectonucleotide pyrophosphatase/phosphodiesterase 1) gene mutates. Idiopathic infantile arterial calcification is rare, only occurring in 1 out of 391,000 births.
When babies are born with this disorder, the prognosis is typically not good. There have been a few reports of babies living until adulthood, but unfortunately, they are few and far between, and as of 2006, the oldest survivor with this disease was 25. People who do go on to live past their teens fight high blood pressure and heart problems.
There are transplants available for babies who are born with this genetic condition but in most cases these babies do not survive long enough to reach the weight requirement for the surgery. In most cases, babies who are born with idiopathic infantile arterial calcification do not survive longer than six months of age. These statistics do not change drastically with medication or other types of treatments.
Symptoms & Complaints
While the baby is inside the uterus a key symptom is polyhydramnios, which means there is too much fluid inside the amniotic sac. Other symptoms can include decreased fetal movement and hydrops fetalis. Once the baby is born, symptoms can include swelling, cyanosis, poor feeding, and vomiting. Some babies also have a distended stomach and cardiac arrest.
Causes
Idiopathic infantile arterial calcification is genetic and most often affects the arteries leading to the kidneys, heart, and aorta. According to the United States National Library of Medicine, this condition is inherited in an autosomal recessive pattern. This means that both parents must contain the mutated gene in order for their offspring to inherit the disease.
Diagnosis & Tests
In many cases, idiopathic infantile arterial calcification is detected while the baby is still in the womb through prenatal diagnosis. Fetal ultrasounds can detect calcification in the liver. However, there are some babies who do not show symptoms until right after birth or up to six months of age.
Computed tomography (CT) scans can reveal calcification of the arterial walls. A type of ultrasound, echocardiograms can reveal bright spots on the ascending aorta, among other areas of the heart, which indicates calcification. Echocardiograms may show calcification of the vessels around the aorta at week 23.
Doctors consider the diagnosis of this genetic condition when babies present with high blood pressure, heart attack, and rickets. An ultrasound of the brain may be helpful. If this test shows a white brain matter injury such as (periventricular leukomalacia or dilated lateral ventricles (ventriculomegaly), it can be an indication of this condition.
Prospective parents and pregnant women may undergo genetic testing for the presence of associated genetic mutations.
Treatment & Therapy
If this condition is diagnosed while the mother is still pregnant, doctors often try low doses of certain medications to reduce the amount of calcification inside the arteries. Doctors administer doses of bisphosphonates, which is a type of medicine used to prevent the loss of bone mass. In some cases, using these types of medicines resulted in a signification reduction in symptoms in babies. Bisphosphonates are given before birth and shortly thereafter for optimal results.
Once the baby is born, doctors often use medications to manage the symptoms the baby is having. Since high blood pressure is a key symptoms, doctors often prescribe antihypertensive drugs to keep it under control. When the baby's arteries are very constricted, aspirin may be given to thin the blood. This reduces the risk of heart attack and stroke.
There are often conditions that develop secondarily to idiopathic infantile arterial calcification. If so, doctors must perform treatments to avoid serious complications. This can include treatment for rickets and for orthopedic problems associated with arterial calcification such as spinal fusion. Fiberoptic intubation in order to promote breathing may be required in the latter case.
Prevention & Prophylaxis
At the time a baby is conceived, it has a 25 percent chance of being affected if they have a sibling with the condition. The baby also has a 50 percent chance of carrying the gene but not ever having symptoms if their sibling has or had the disorder. 25 percent of these babies could avoid the gene altogether and never be a carrier of the gene.
If the gene does exist in both parents, doctors recommend genetic counseling before pregnancy if at all possible. This gives potential parents information regarding the risks of the disorder. Genetic counselors can also offer different reproductive options to those who are interested.