Leber hereditary optic neuropathy
- Leber optic atrophy
- Leber’s disease
- Optic atrophy, Leber type
However, a significant percentage of people with a mutation that causes Leber hereditary optic neuropathy do not develop any features of the disorder. Specifically, more than 50 percent of males with a mutation and more than 85 percent of females with a mutation never experience vision loss or related medical problems. Additional factors may determine whether a person develops the signs and symptoms of this disorder. Environmental factors such as smoking and alcohol use may be involved, although studies of these factors have produced conflicting results. Researchers are also investigating whether changes in additional genes, particularly genes on the X chromosome, contribute to the development of signs and symptoms.
The Human Phenotype Ontology provides the following list of signs and symptoms for Leber hereditary optic neuropathy. If the information is available, the table below includes how often the symptom is seen in people with this condition. You can use the MedlinePlus Medical Dictionary to look up the definitions for these medical terms.
The Human Phenotype Ontology (HPO) has collected information on how often a sign or symptom occurs in a condition. Much of this information comes from Orphanet, a European rare disease database. The frequency of a sign or symptom is usually listed as a rough estimate of the percentage of patients who have that feature.
The frequency may also be listed as a fraction. The first number of the fraction is how many people had the symptom, and the second number is the total number of people who were examined in one study. For example, a frequency of 25/25 means that in a study of 25 people all patients were found to have that symptom. Because these frequencies are based on a specific study, the fractions may be different if another group of patients are examined.
Sometimes, no information on frequency is available. In these cases, the sign or symptom may be rare or common.
- Leber hereditary optic neuropathy. Genetics Home Reference (GHR). 2006; http://ghr.nlm.nih.gov/condition/leber-hereditary-optic-neuropathy. Accessed 12/2/2011.
- Yu-Wai-Man P, Chinnery PF. Leber Hereditary Optic Neuropathy. GeneReviews. July 2011; http://www.ncbi.nlm.nih.gov/books/NBK1174/. Accessed 12/2/2011.