Albinism, Ocular Type 1

Background and History: 

It is unknown for how long people have recognized individuals with decreased pigmentation, often called albinos.  We now know of a number of gene mutations that cause a variety of disorders in which the skin and hair are pale or even white.  In these disorders, the pigmentation in the eyes is also affected, most noticeably in the iris which is usually pale blue.  However, the gene mutations also affect an important layer beneath the retina, known as the retinal pigment epithelium, visible when an eye doctor looks into the eye.

Clinical Correlations: 

Ocular albinism is a disorder in which the decrease in pigmentation affects only the eye.  The iris is pale blue and often has defects that allow light to shine through.  The pigmentary layer of the retina is also lacking normal pigmentation so that the retina is highly transparent.  More seriously, in ocular albinism as in other forms of albinism, the central portion of the retina is not formed normally and the nerves connecting the eye to the brain are incorrectly routed.  Together these result in decreased vision and loss of depth perception in most people.  Abnormal sensitivity to light and nystagmus (dancing eyes) are often seen as well.

No other health problems are associated with this disorder.

Genetics: 

This is an X-linked recessive condition in which in general only males have the complete clinical picture.  It is not uncommon for females who carry the mutation in one of their X-chromosomes to have some features such as abnormal pigmentation in the iris and retina although vision is seldom affected.  Such females will usually pass the abnormal X chromosome to half their children so that half of their sons will have ocular albinism and half of their daughters will be carriers like themselves.  Males with ocular albinism will not have children with the same disorder but half of their daughters would be expected to be carriers with one abnormal X-chromosome.

Diagnosis and Prognosis: 

Ocular albinism cannot be diagnosed by simple inspection alone.  Light blue eyes may suggest the diagnosis in families in which the disorder is known to occur, but blue eyes are not uncommon in the general population.  The presence of ‘dancing eyes’ and decreased vision are also suggestive of this condition but only your eye doctor can make the precise diagnosis.

No treatment is available for this pigmentary disorder.

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