RT Book, Section A1 Bianchi, Diana W. A1 Crombleholme, Timothy M. A1 D'Alton, Mary E. A1 Malone, Fergal D. SR Print(0) ID 1106400360 T1 Chondrodysplasia Punctata T2 Fetology: Diagnosis and Management of the Fetal Patient, 2e YR 2015 FD 2015 PB McGraw-Hill Education PP New York, NY SN 978-0-07-144201-5 LK obgyn.mhmedical.com/content.aspx?aid=1106400360 RD 2024/03/28 AB Key PointsChondrodysplasia punctata comprises a group of genetically heterogenous skeletal dysplasias characterized by small calcified densities in the epiphyses of the long bones.The rhizomelic form (RCDP) is more severe and inherited as an autosomal recessive condition. Rhizomelic chondrodysplasia punctata is a disorder of the peroxisomes.The nonrhizomelic form, also known as Conradi–Hünermann syndrome, can be inherited as an autosomal dominant, X-linked recessive or dominant condition. It is generally milder.Sonographic findings include profound humeral and femoral shortening in rhizomelic chondrodysplasia punctata. Multiple hyperechoic foci (puncta), nasal hypoplasia, midface depression, vertebral anomalies, and congenital heart defects are associated with both RCDP and Conradi–Hünermann syndrome.Differential diagnosis includes skeletal dysplasias, autosomal trisomies, Zellweger syndrome, disorders of vitamin K metabolism, warfarin exposure, Smith–Lemli–Opitz syndrome, and GM1gangliosidosis.Pregnant women carrying fetuses with punctate calcifications should be referred to a tertiary center and to a medical geneticist. Chromosome analysis is indicated to rule out trisomy and deletions of Xp22.3.There are three types of RCDP; type 1 is most common, caused by mutations in PEX7. Molecular diagnosis is possible for all three types.Prognosis is poor for RCDP. Only 50% of affected infants survive past the age of 6 years. All affected infants have severe failure to thrive, mental retardation, joint contractures, and cataracts.Infants affected with Conradi–Hünermann syndrome have milder symptoms, generally normal intelligence and, with the exception of the X-linked dominant form in males, a fairly normal lifespan.