Rare Infectious Disease News

Disease Profile

Primary open angle glaucoma juvenile onset 1

Prevalence
Prevalence estimates on Rare Medical Network websites are calculated based on data available from numerous sources, including US and European government statistics, the NIH, Orphanet, and published epidemiologic studies. Rare disease population data is recognized to be highly variable, and based on a wide variety of source data and methodologies, so the prevalence data on this site should be assumed to be estimated and cannot be considered to be absolutely correct.

Unknown

Age of onset

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ICD-10

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Inheritance

Autosomal dominant A pathogenic variant in only one gene copy in each cell is sufficient to cause an autosomal dominant disease

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Autosomal recessive Pathogenic variants in both copies of each gene of the chromosome are needed to cause an autosomal recessive disease and observe the mutant phenotype

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X-linked
dominant X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome.

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X-linked
recessive Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder

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Mitochondrial or multigenic Mitochondrial genetic disorders can be caused by changes (mutations) in either the mitochondrial DNA or nuclear DNA that lead to dysfunction of the mitochondria and inadequate production of energy.

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Multigenic or multifactor Inheritance involving many factors, of which at least one is genetic but none is of overwhelming importance, as in the causation of a disease by multiple genetic and environmental factors.

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Not applicable

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Other names (AKA)

JOAG1; Glaucoma 1, open angle, A; GLC1A;

Categories

Congenital and Genetic Diseases; Eye diseases

Summary

The following summary is from Orphanet, a European reference portal for information on rare diseases and orphan drugs.
orphanet

Orpha Number: 98977

Definition
A primary early-onset glaucoma that is characterized by early onset, severe elevation of intra ocular pressure of rapid progression, leading to optic nerve excavation and, when untreated, substantial visual impairment.

Epidemiology
The disorder is estimated to occur in 0,32/100 000 individuals before the age of 20 years.

Clinical description
Juvenile glaucoma (JG) typically presents between the ages of 5 to 18 years, but it can appear later. Patients are initially asymptomatic and are often discovered incidentally on a routine examination. JG is generally bilateral; there can be a marked asymmetry between the two eyes. The intraocular pressure increases progressively leading to optic nerve excavation and eventually, substantial visual impairment and field loss.

Etiology
JG is caused by impaired outflow of aqueous humor through the trabecular meshwork and into the Schlemm canal. Mutation in MYOC (1q23-q24) genes have been found in patients with JG. MYOC gene codes for the glycoprotein myocilin that is found in the trabecular meshwork and ocular tissue and mutations are disease-causing.

Diagnostic methods
The diagnosis is suspected with the presence of clinical features such as increased intraocular pressure and optic nerve excavation. On gonioscopy the angle appears normal. Typical features of primary congenital glaucoma such as corneal edema and Haab's striae are not present. The refraction test reveals myopia. Typical glaucomatous field defects can be documented. Optic nerve head shows glaucomatous optic neuropathy.

Differential diagnosis
Differential diagnoses include other forms of open angle glaucoma that can occur at any age, late recognized congenital glaucoma, steroid induced glaucoma, traumatic glaucoma and inflammatory glaucoma.

Genetic counseling
Transmission is autosomal dominant with high penetrance. Genetic testing can be used to identify family members at risk of developing JG. Genetic counseling should be proposed to individuals having the disease-causing mutation informing them that there is 50% risk of passing the mutation to offspring.

Management and treatment
Medical therapy (carbonic anhydrase inhibitors, beta blockers, prostaglandin analogues) is often useful in the treatment of JG. When the condition becomes unresponsive to medications, angle surgery (goniotomy, trabeculotomy), filtration surgery (trabeculectomy), LASER treatment (angle laser surgery or cyclodiode laser therapy) and/or aqueous shunt devices can be considered.

Prognosis
Prognosis is good in patients diagnosed and treated early. Without treatment, the evolution towards blindness is possible.

Visit the Orphanet disease page for more resources.

Symptoms

This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

Medical Terms Other Names
Learn More:
HPO ID
30%-79% of people have these symptoms
Abnormal anterior chamber morphology
0000593
Abnormality iris morphology
Abnormality of the iris
0000525
Glaucomatous visual field defect
0007854
Ocular hypertension
High eye pressure
0007906
Open angle glaucoma
0012108
Optic neuropathy
Damaged optic nerve
0001138
Peripheral visual field loss
Loss of peripheral vision
0007994
5%-29% of people have these symptoms
High myopia
Severe near sightedness
Severely close sighted
Severely near sighted

[ more ]

0011003
Increased cup-to-disc ratio
0012796
Temporal optic disc pallor
0012511
1%-4% of people have these symptoms
Central scotoma
Central blind spot
0000603
Retinal arterial occlusion
0025326
Retinal vein occlusion
0012636
Percent of people who have these symptoms is not available through HPO
Abnormal iris vasculature
Abnormality of iris blood vessels
0007905
Autosomal dominant inheritance
0000006
Glaucoma
0000501
Myopia
Close sighted
Near sighted
Near sightedness
Nearsightedness

[ more ]

0000545

Diagnosis

Making a diagnosis for a genetic or rare disease can often be challenging. Healthcare professionals typically look at a person’s medical history, symptoms, physical exam, and laboratory test results in order to make a diagnosis. The following resources provide information relating to diagnosis and testing for this condition. If you have questions about getting a diagnosis, you should contact a healthcare professional.

Testing Resources

  • The Genetic Testing Registry (GTR) provides information about the genetic tests for this condition. The intended audience for the GTR is health care providers and researchers. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.

Learn more

These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

In-Depth Information

  • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
  • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
  • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.