Chondrodysplasia punctata Q77.3

Autosomal recessive hereditary, lethal, peroxisomal disease with characteristic phenotype. Biochemical increase of phytanic acid in plasma, decreased synthesis of plasmalogen and defective oxidation of phytanic acid in fibroblasts.

Predominantly autosomal recessive inherited gene mutations that consecutively impair various peroxisomal functions. Most patients have partial defects in acyl-CoA dihydroxyacetone phosphate acyltransferase (RDCP type 2), impaired plasmalogen biosynthesis, impaired phytanate degradation, and delayed maturation of peroxisomal 3-oxoacyl-CoA thiolase. Several gene loci have been described, with defects associated with different subtypes of the disease.

• RCDP type 1: mutations of peroxisomal biogenesis factor-7(PEX7 gene; gene locus: 6q22-q24).
• RCDP type 2: mutations of the glyceronephosphate O-acyltransferase gene (GNPAT gene; gene locus: Chr. 1).
• RCDP type 3: mutations of the alkylglycerone-phosphate synthase gene (AGPS gene; gene locus: 2q31).

1. Heymans HSA, Oorthuys JWE, Nelck G et al (1986) Peroxisomal abnormalities in rhizomelic chondrodysplasia punctata. J Owner Metab Dis 9 Suppl 2: 329-331
2. Lightwood RC (1930/31) Congenital deformities with stippled epiphyses and congenital cataract. Proc Roy Soc Med 24: 564-566
3. White AL et al (2003) Natural history of rhizomelic chondrodysplasia punctata. At J Med Genet 118A: 332-342