AssessmentsAlagille syndrome (NORD)
USMLE® Step 1 style questions USMLE
USMLE® Step 2 style questions USMLE
A 7-month-old boy comes to the clinic because of a concerning yellowing of his skin. On physical examination jaundice is visible and a triangular shaped face. There is also a ring-like opacity around the edge of the cornea on eye exam. Plain film shows "butterfly-shaped" vertebrae. Which of the following is the most likely diagnosis?
Content Reviewers:Yifan Xiao, MD
Alagille syndrome, or ALGS, is a genetic disorder that can affect multiple organs in the body and cause a variety of abnormalities.
Alagille syndrome typically affects the liver but it can also cause problems in the heart, kidney, eyes, and bones.
Affected individuals have a reduced number of bile ducts in the liver.
As a result, there is a decrease in bile flow, also known as cholestasis.
Some patients may also have an enlarged spleen or liver.
Because many necessary vitamins and nutrients need bile to be properly absorbed, people with Alagille syndrome may also experience select vitamin deficiencies, or poor weight gain and growth.
Deficiencies in specific vitamins may result in vision problems from a lack of Vitamin A, bone weakness from a lack of vitamin D, developmental delays from a lack of Vitamin E, and blood clotting problems from a lack of Vitamin K.
The heart can also be impacted by Alagille syndrome.
The most common finding in ALGS patients is peripheral pulmonary arterial stenosis.
This means that the blood vessels carrying blood to the lungs are narrowed.
The stenosis typically manifests as a heart murmur, or an extra sound in the heartbeat.
Symptoms are based on the degree of narrowing of the blood vessel and some people may have no symptoms while others may have dizziness, shortness of breath, increased sweating, chest pains, and cyanosis, or bluish colored skin.
Children with Alagille syndrome may also have congenital heart defects, or heart problems that one is born with.
The most common congenital heart defect in ALGS patients is tetralogy of Fallot.
Congenital heart defects may result in dizziness and fainting, fatigue, shortness of breath, swelling in the hands, cyanosis and developmental delay.
There are many distinct facial features that are characteristic of Alagille syndrome.
These include a broad forehead, deeply set and widely spaced eyes, and a pointed chin.
In the eyes, Alagille syndrome can cause a thickened lining of the cornea called posterior embryotoxon.
This finding should not affect vision.
Some patients may have irregularly shaped bones in the vertebrae called butterfly vertebrae.
Other symptoms include abnormalities in the kidney or pancreas, stenosis of other blood vessels throughout the body, and mild cognitive impairment.