The cause is a genetic mutation that results in low levels of plasmalogens, which are a type of lipid found in cell membranes throughout the body, but whose function is not known.[2]
Signs and symptoms
Rhizomelic chondrodysplasia punctata has the following symptoms:[4][1]
Bilateral shortening of the femur, resulting in short legs
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 autosomalrecessive manner.[2]
Pathophysiology
ACAA1
The mechanism of rhizomelic chondrodysplasia punctata in the case of type 1 of this condition involves a defect in PEX7, whose product is involved in peroxisome assembly. There are 3 pathways that depend on peroxisomal biogenesis factor 7 activities, including:[4][5][verification needed]
The diagnosis of rhizomelic chondrodysplasia punctata can be based on genetic testing[6] as well as radiography results, plus a physical examination of the individual.[3]
Type 2 (RCDP2) is associated with DHAPAT mutations.[7]
Type 3 (RCDP3) is associated with AGPS mutations.[8]
Treatment
Management of rhizomelic chondrodysplasia punctata can include physical therapy; additionally orthopedic procedures improved function sometimes in affected people.[4]
Prognosis
The prognosis is poor in this condition,[3] and most children die before the age of 10.[4] However, some survive to adulthood, especially if they have a non-classical (mild) form of RCDP.[4]
Children with classical, or severe, RCDP1 have severe developmental disabilities. Most of them achieve early developmental skills, such as smiling, but they will not develop skills expected from a baby older than six months (such as feeding themselves or walking).[4] By contrast, children with non-classical mild RCDP1 often learn to walk and talk.[4]
^ ab"Rhizomelic chondrodysplasia punctata type 1". Genetic and Rare Diseases Information Center (GARD) – an NCATS Program. US National Library of Medicine. Archived from the original on 24 January 2017. Retrieved 23 January 2017.
Braverman NE, Steinberg SJ, Fallatah W, et al. (2020). Adam MP, Ardinger HH, Pagon RA, et al. (eds.). "Rhizomelic Chondrodysplasia Punctata Type 1". GeneReviews® [Internet]. University of Washington. PMID20301447. NBK1270. Archived from the original on 2017-01-18. Retrieved 2017-01-16.
Braverman NE, Bober MB, Brunetti-Pierri N, et al. (2020). Adam MP, Ardinger HH, Pagon RA, et al. (eds.). "Chondrodysplasia Punctata 1, X-Linked". GeneReviews® [Internet]. University of Washington. PMID20301713. Archived from the original on 2022-03-09. Retrieved 2022-03-09.
Kumble S, Savarirayan R (2020). Adam MP, Ardinger HH, Pagon RA, et al. (eds.). "Chondrodysplasia Punctata 2, X-Linked". GeneReviews® [Internet]. University of Washington. PMID21634086. NBK55062. Archived from the original on 2020-08-05. Retrieved 2022-03-09.
