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Alagille syndrome (NORD)





Population genetics
Genetic disorders
Down syndrome (Trisomy 21)
Edwards syndrome (Trisomy 18)
Patau syndrome (Trisomy 13)
Fragile X syndrome
Huntington disease
Myotonic dystrophy
Friedreich ataxia
Turner syndrome
Klinefelter syndrome
Prader-Willi syndrome
Angelman syndrome
Beckwith-Wiedemann syndrome
Cri du chat syndrome
Williams syndrome
Alagille syndrome (NORD)
Polycystic kidney disease
Familial adenomatous polyposis
Familial hypercholesterolemia
Hereditary spherocytosis
Huntington disease
Li-Fraumeni syndrome
Marfan syndrome
Multiple endocrine neoplasia
Myotonic dystrophy
Treacher Collins syndrome
Tuberous sclerosis
von Hippel-Lindau disease
Polycystic kidney disease
Cystic fibrosis
Friedreich ataxia
Gaucher disease (NORD)
Glycogen storage disease type I
Glycogen storage disease type II (NORD)
Glycogen storage disease type III
Glycogen storage disease type IV
Glycogen storage disease type V
Mucopolysaccharide storage disease type 1 (Hurler syndrome) (NORD)
Krabbe disease
Niemann-Pick disease types A and B (NORD)
Niemann-Pick disease type C
Primary ciliary dyskinesia
Phenylketonuria (NORD)
Sickle cell disease (NORD)
Tay-Sachs disease (NORD)
Wilson disease
Fragile X syndrome
Alport syndrome
X-linked agammaglobulinemia
Fabry disease (NORD)
Glucose-6-phosphate dehydrogenase (G6PD) deficiency
Mucopolysaccharide storage disease type 2 (Hunter syndrome) (NORD)
Lesch-Nyhan syndrome
Muscular dystrophy
Ornithine transcarbamylase deficiency
Wiskott-Aldrich syndrome
Mitochondrial myopathy
Autosomal trisomies: Pathology review
Muscular dystrophies and mitochondrial myopathies: Pathology review
Miscellaneous genetic disorders: Pathology review
High Yield Notes
7 pages

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.

One of the main liver features of Alagille syndrome is the disruption of bile flow from the liver to the gallbladder.

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.

The symptoms and signs of cholestasis include jaundice, or the yellowing of skin and eyes, severe itching, pale colored stools, and dark urine.

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.

Other possible defects include atrial septal defects, patent ductus arteriosus, and coarctation of the aorta.

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.


Alagille syndrome (NORD) is a rare, autosomal dominant disorder that affects the liver, heart, and other parts of the body. The most common symptom of Alagille syndrome is jaundice (yellowing of the skin and eyes) in infancy. Other symptoms may include malformed bones, kidney problems, and irregular developmental milestones. There is no cure for Alagille syndrome, but many affected individuals can lead normal, productive lives with proper care.