Coloboma, Microphthalmia, Albinism, and Deafness

Background and History: 

This condition has so far been reported in two families and the full description of the clinical features is not yet available.  It results from two mutations in the same gene.

Clinical Correlations: 

The most striking feature is the lack of pigmentation in hair, skin, and eyes.  Both reported patients had severe hearing loss at birth with small eyes and relatively prominent skulls.  The cornea (windshield) is small and often is covered by scar tissue.  One individual at least had cataracts and the eyes are incompletely formed resulting in colobomas (lack of fusion of embryonic tissues).  The optic nerves are small.  X-rays may show abnormalities of bone growth (osteopetrosis).  The external ears may be rotated posteriorly and one patient was said to have a low muscle tone (hypotonia).

Genetics: 

This seems to be an autosomal recessive condition based on the two studied patients.  The 4 parents, who also had some clinical features (such as hearing loss and decreased pigmentation), contributed two different mutations to each of the affected offspring.  The risk of additional affected children for each of the the two sets of parents is 25%.

Diagnosis and Prognosis: 

Neurologists, orthopedists, pediatricians, audiologists and ophthalmologists should collaborate on the diagnosis and care of this complex syndrome.  However, gene testing is necessary for confirmation.

The fair skin and lack of hair pigmentation is evident at birth.  Evidence of decreased hearing requires confirmation by hearing tests.  X-rays can document bony changes.  A full ophthalmological examination should reveal the eye abnormalities although these are not diagnostic for the condition.

Additional Information
Inheritance/Pedigree: 
Autosomal recessive