Alagille syndrome is also known as Alagille-Watson syndrome or arteriohepatic dysplasia. It’s a genetic disease affecting the heart, liver and other organs. The first symptoms appear in childhood.
This disease It was first described in 1969 by the pediatrician The French Daniel Alagille. It is currently estimated to affect 1 in 70,000 babies born. However, some authors believe that its prevalence may be as high as 1 in 30,000 births.
Level the severity of Alagille syndrome is highly variable. While in some patients the symptoms go unnoticed, in others it causes serious health conditions, which can lead to a heart or liver transplant.
What is Alagille Syndrome?
Alagille syndrome is a disease that affects several organs. These include the heart, liver, spine, face, eyes, blood vessels and kidneys. It was originally called syndromic insufficiency of the bile ducts.
This disturbance is caused by the mutation in a gene called JAGGED1 or in the NOTCH2 gene. Up to 94% of cases correspond to the JAGGED1 mutation, while only between 1 and 2% have to do with NOTCH2. In all other cases the cause is unknown.
The most characteristic of Alagille’s syndrome is that patients have liver disease caused by a decrease in the number of bile ducts.
Causes
The JAGGED1 gene is located on chromosome 20. It controls the formation of a protein called JAG1. For its part, the NOTCH2 gene is located on chromosome 1. When the mutation occurs in these genes, the nucleus is altered mobile phone.
All this leads to the activation of other genes that directly affect the growth and development of various organs in the body. Mainly from the brain, liver, skeleton and kidneys. Science currently ignores why the mutation causes these effects.
Alagille syndrome is predominantly hereditary. When a parent has the disease, they also have one normal and one mutated gene.. Therefore, their children have a 50% chance of inheriting the disease. In 20% of cases the syndrome is caused by a new mutation.
Clinical features
Thanks to the investigations conducted since 1969, it was possible to establish this Five underlying abnormalities are present in Alagille syndrome.. This set of abnormalities is called the “classical criteria” and from this the diagnosis is made. The components of the classical criterion are:
- Liver disease. It is present in about 95% of cases.
- Heart disease. It occurs in about 90% of affected patients.
- ophthalmological manifestations. They are present in 76% to 95% of patients.
- Skeletal abnormalities. A conformation of the vertebrae called “butterfly wings” is observed in about 80% of patients.
- Specific facial features. They are subtle, but recognizable. They basically include a prominent forehead, deep set eyes, a straight nose with a bulbous tip, etc.
It is also normal for there to be vascular involvementrenal involvement, growth retardation, pancreatic involvement, and learning disabilities.
The decrease in the number of bile ducts is considered a fundamental pattern in Alagille syndrome. Typical symptoms include jaundice, eye spots, and xanthelasma (small, fatty growths around the eyelids).
Diagnosis and prognosis
Alagille syndrome diagnosed by careful clinical examination, blood tests and other special tests. The normal thing is that when there is a suspicion of the disease, a blood test and a urine test are ordered.
These tests measure the amount of bilirubin in the blood. They also offer insight into the functioning of the liver and kidneys. An ultrasound of the liver is also usually ordered. and kidneys and a liver biopsy.
A liver biopsy is performed with a needle and lets us know if there is a deficiency of the bile ducts. Typically, x-rays, heart exams, and eye exams are also done. It is possible to detect the mutation of genes through a blood test.
Most patients with Alagille syndrome they can lead practically normal lives. Only in the presence of severe heart or liver problems can life expectancy be reduced.
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