Aland Island Eye Disease

Background and History: 

This is a rare disorder of the eye first described in 1964 in a large family of Norwegian descendents on the island of Aland in the Bothnian Sea.  Males are primarily affected but females may have mild symptoms as well.  It has interesting similarities to a type of albinism and a form of congenital stationary night blindness also occurring primarily in males.

Clinical Correlations: 

Males with this disorder may experience severe, progressive near-sightedness, 'dancing eyes', a specific form (protan) of color blindness and decreased ability to see at night.  Some patients have decreased pigmentation in the retina and iris.  Malformation of the retina structures may result in a mild to severe decrease in vision.  Carrier females in this X-linked disorder may have minor eye disease as well with subtle color vision changes and changes in eye movements.

No consistent systemic abnormalities have been reported. 

Genetics: 

This is an X-linked recessive disorder, so called because the responsible mutation is in a gene on the X chromosome.  Since males have only one X chromosome, there is no 'normal' X chromosome to counterbalance the harmful effects of the single gene change and they have the most serious clinical disease as noted above.  Occasional females whose mutant X chromosome may be more active can also have mild disease.  Since males pass on only their Y chromosome to their sons, none will have this eye disease but the single mutant X chromosome goes to all daughters so they become obligatory carriers with the potential to have affected sons.

Diagnosis and Prognosis: 

The diagnosis may be suspected in males by an eye doctor who finds the characteristic symptoms and signs.  However, the clinical similarities between Aland Island Eye Disease and X-linked forms of night blindness and albinism, other studies such as electroretinograms and gene studies may be necessary to rule out other disease.  The only treatment is correction of the near sightedness with glasses and contact lenses.  The use of low vision aids can also be helpful.

Additional Information
Inheritance/Pedigree: 
X-linked recessive, carrier mother
X-linked recessive, father affected