Arthrogryposis Renal Dysfunction Cholestasis Syndrome
Type of disease: Rare conditions
Arthrogryposis renal dysfunction cholestasis (ARC) syndrome is a very rare syndrome that has affected less then 100 people worldwide. This syndrome typically starts before the baby is born and continues into infancy. ARC syndrome mainly affects the liver, kidney, skin, central nervous, and musculoskeletal systems. One of the main symptoms is arthrogryposis, or abnormalities in the joints, which causes limbs, like arms and legs, to become more difficult to move. Other major features of this condition include renal tubular acidosis (kidney problems that lead to the buildup of acid in the body), and jaundice (a yellow-coloring of an individual). Other symptoms that appear less frequently include dry and scaly skin, problems with blood platelets, and absence of the corpus callosum, the part of the brain that connects the two hemispheres. Most patients with ARC syndrome do not survive past the first year of life.
It has been found that in most cases of this disorder, there are mutations in the VPS33B and VIPAR genes. These genes are involved in maintaining the structure of the cells in our bodies and making sure proteins get transported correctly. When these genes are damaged, proteins can accumulate in the cell, which becomes a problem. ARC syndrome is passed on from parent to child in an autosomal recessive manner. Autosomal recessive means that an individual must have two copies of the changed gene or mutation that causes the condition. A person with one changed gene would be a carrier of the condition but usually will not have any symptoms. If both parents are carriers of ARC syndrome, each child has a one in four chance (25%) of having the disease.
ARC syndrome is usually diagnosed by looking at clinical features, taking cell samples from different organs, and doing DNA testing. Treatment and management varies based on the case, though in general, there is no specific treatment for this syndrome.