Rhizomelic chondrodysplasia punctata type 1 (RCDP1) is an inherited disease that causes small physical size, certain characteristic bone problems, mental disability, and cataracts. Most children with the classic form of RCDP1 do not live beyond the age of 10, and some will die in infancy. There is also a mild form of the disease, but it is less common.
Children with the classic form of RCDP1 typically have shortened arm and leg bones. They are often born smaller than average and fail to grow at the expected rate, leaving them much smaller than normal children. The cartilage in children with RCDP1 typically has round or oval areas of calcification. Affected children have stiff, painful joints which may lose the ability to bend normally. They will also have characteristic facial features.
Children with this disease are often severely mentally disabled and fail to develop skills beyond the level of a normal six month-old. The majority also develop seizures.
Other symptoms that may be seen include rough and scaly skin, a cleft palate, and malformations of the spinal column. These children usually develop cataracts early in life that obscure their vision. Most have recurrent lung infections which can be life-threatening.
In the mild form of the disease, mental and growth disability are less severe. Some have shortened limbs while others do not. All children with this form of the disease have areas of calcification in their cartilage and cataracts.
Fewer than 1 in 100,000 infants worldwide is affected by RCDP1. The disease affects children of every ethnicity, however one common mutation known as L292X is most common in Caucasians of Northern European descent.
There is no cure for RCDP1. Surgery to remove cataracts can restore some vision. Physical therapy may help preserve movement. Other bone surgery may also be helpful. Many children with the disease require a feeding tube. Their lung function must be closely monitored to avoid infection and choking hazards.
Those with milder forms of the disease may benefit from a specialized diet.
The prognosis for a child with the classic form of RCDP1 is poor. Many die in the first or second year of life, and few survive beyond the age of 10. Breathing problems are often the cause of death.
Those with milder forms of the disease may live longer, however there have been relatively few known cases with which to determine average longevity.
A medical database of genetic disorders funded by the National Institutes of Health and developed at the University of Washington, Seattle. Much of the language in GeneReviews is meant for physicians and other scientists.