A metabolic disorder involving a mutation in genes such as PEX7, GNPAT, and AGPS, and characterized by symptoms such as rhizomelia, seizures, cataracts, and recurrent respiratory problems
Rhizomelic chondrodysplasia punctata is a metabolic disorder caused by a dysfunctional peroxisome. Thus, it is one of the many types of peroxisomal disorder. This type of disorder affects the brain development. It is also characterized by symptoms such as rhizomelia (i.e. a disproportion in the length of upper arms and thighs), seizures, cataracts, intellectual disability, and recurrent respiratory problems.
Rhizomelic chondrodysplasia punctata is caused by a mutation in the genes such as PEX7, GNPAT, and AGPS; PEX7 gene mutation is the most common. These genes code for proteins that take roles in the synthesis of plasmalogens. Mutation in PEX7 gene accounts for the rhizomelic chondrodysplasia punctata type 1. Mutation in GNPAT gene is associated with rhizomelic chondrodysplasia punctata type 2. Mutation in AGPS gene leads to rhizomelic chondrodysplasia punctata type 3.
Rhizomelic chondrodysplasia punctata is inherited in an autosomal recessive pattern. This means that the individual has two copies of the defective gene and therefore manifests symptoms associated with the disease. A carrier of the disease would have only one copy of the defective gene and therefore may not show symptoms.