Rhizomelic Chondrodysplasia Punctata
Rhizomelic chondrodysplasia punctata is a rare developmental brain disorder characterized by systemic shortening of the proximal bones (i.e. rhizomelia), seizures, recurrent respiratory tract infections and congenital cataracts. The affected individuals have low levels of plasmalogens.
Signs and symptoms
Rhizomelic chondrodysplasia punctata has the following symptoms:
- Bilateral shortening of the femur
- Post-natal growth problems (deficiency)
- Cataracts
- Intellectual disability
- Possible seizures
- Possible infections of respiratory tract
Genetics
This condition is a consequence of mutations in the PEX7 gene, the GNPAT gene (which is located on chromosome 1) or the AGPS gene. The condition is acquired in an autosomal recessive manner.
Pathophysiology
The mechanism of rhizomelic chondrodysplasia punctata in the case of type 1 of this condition one finds that peroxisome objective is PEX7, in peroxisome assembly. There are 3 pathways that count on PEX7 and are:
- AGPS (catalyzes plasmalogen biosynthesis)
- PhYH (catalyzes catabolism of phytanic acid)
- ACAA1 (catalyzes beta-oxidation of VLCFA - straight)
Diagnosis
The diagnosis of rhizomelic chondrodysplasia punctata can be based on genetic testing as well as radiography results, plus a physical examination of the individual.
Types
- Type 1 (RCDP1) is associated with PEX7 mutations; these are peroxisome biogenesis disorders where proper assembly of peroxisomes is impaired.
- Type 2 (RCDP2) is associated with DHAPAT mutations
- Type 3 (RCDP3) is associated with AGPS mutations
Treatment
Management of rhizomelic chondrodysplasia punctata can include physical therapy; additionally orthopedic procedures improved function sometimes in affected people. However, the prognosis is poor in this condition.
See also
- Plasmalogen
- Peroxisomal disorder