This is a recently described hereditary disorder that involves primarily the eyes and the skeleton.
Infants may have unusual facial features at birth including a short neck, downward slanting openings between the eyelids, an enlarged skull with prominence of the forehead, small jaw, large low-set ears, and short fingers and toes. Older children are often short in stature and appear to have an abnormally short neck. Some intellectual disabilities and delays in speech, feeding, and walking are present.
Around the beginning of the second decade of life individuals note increasing difficulty seeing at night and a narrowing of side vision. At about this time pigmentary changes can be seen in the retina of the eye and an ERG (electroretinogram) confirms progressive damage to the rods and cones. The levels of vision are unknown.
This is an autosomal recessive condition that requires two mutations in a pair of genes, one from each of the parents. The parents are clinically normal but confer a risk of 25% of this condition to each of their offspring.
The facial dysmorphism is usually too nonspecific to enable diagnosis at birth. However, delays in growth and development may lead to further evaluations in childhood that could suggest the diagnosis. By the second decade of life the visual symptoms cause significant problems and the skeletal defects such as shortness of stature may enable a more specific conclusion. Pediatricians, ophthalmologists, neurologists, and orthopedists may collaborate on this condition.
No general treatment is known to be effective. Low vision aids and night vision devices can be helpful especially for educational purposes. Nothing is known regarding longevity.