Cataracts 34

Background and History: 

In the normal condition, the lens of the eye is clear and transparent and serves to focus light on the retina.  However, whenever there is an opacity, no matter the appearance or the density in the lens, it is called a cataract.  Vision is usually but not always reduced.  There are many kinds of cataract and many causes.  Some are secondary to trauma, some caused by infectious diseases, and some are part of other eye diseases.  However, a large number are the result of gene changes (mutations) such as the one described here.

Inherited cataracts may occur in isolation or as in the case here in association with other ocular abnormalities.

Clinical Correlations: 

In cataracts 34 the lens opacities may be present at birth or develop soon thereafter.  There may be associated eye findings such as a small cornea, or an opacity of the cornea.  Nystagmus (constant to-and-fro movements of the eye) is sometimes present as well. 

There are no abnormalities in other parts of the body.

Genetics: 

This type of cataract is transmitted in an autosomal recessive pattern.  A mutation in both members of a gene pair is required for the condition to be expressed.  Each parent has the mutation in only one of the pair and are clinically normal.  However, each offspring of two such parents have a 25% chance of inheriting both mutations and having this condition.

Diagnosis and Prognosis: 

Congenital cataracts may not always be detected at birth unless a complete eye examination is done.  However, it is important to detect these early to prevent dense amblyopia from occurring.  An eye examination should be done on all newborns.

Lens opacities that interfere with vision should be surgically removed and vision rehabilitation initiated as soon as possible.

Additional Information
Inheritance/Pedigree: 
Autosomal recessive