Microphthalmia, Syndromic 7

Background and History: 

The size of the eyeball is somewhat variable within a normal range in most individuals.  However, in a number of rare syndromes it may be abnormally small and has internal defects.  In some disorders there are abnormalities in other organs such as in this condition in which there are widespread defects.  In rare cases, the eye may even be absent.

Clinical Correlations: 

Usually the eyeball is very small and the cornea (windshield of the eye) is partially or completely opaque.  The cornea may also be small.  Internally, there may be absence of the iris or it may be partially adherent to the cornea and glaucoma sometimes results.

The skin has linear red rash-like defects on the cheeks, nose, and neck that can partially heal with time.  Hernias of the diaphragm (the muscle that separates the chest from the abdomen) are common.  The heart may be enlarged and often has holes in the septum that separates the chambers.  Abnormal heart rhythms (arrhythmias) can occur.  Some patients have hearing loss.  Most individuals are short in stature and the nails may appear abnormal. 

Genetics: 

This is an X-linked dominant disorder that is almost entirely found in females because the gene defect seems to be lethal in males.  Most patients have a missing segment of DNA in the X chromosome but a few have been found to have a change (mutation) in a specific gene on the X chromosome.  Almost all cases occur sporadically but several families have been reported with more than one affected individual.

Diagnosis and Prognosis: 

The diagnosis is often made collaboratively by ophthalmologists and dermatologists but pediatricians and other specialists should also be involved to determine the full extent of internal problems.  Treatment is organ-specific to correct cardiac, diaphragmatic and other defects.  Vision may be absent or severely impaired depending upon the extent of ocular malformation.

Additional Information
Inheritance/Pedigree: 
X-linked dominant, mother affected