Prenatal diagnosis of nonrhizomelic chondrodysplasiapunctata (Conradi‐Hünermann syndrome)

Abstract

Chondrodysplasia punctata has been classified into two major types including the rare autosomal recessive "rhizomelic type" and a more common but genetically heterogenous nonrhizomelic type (referred to by some authors as "Conradi-Hünermann (CH) type"). The former is typically lethal, manifesting serious anomalies, and allowing several instances of confident prenatal diagnosis. The latter being milder has more subtle anomalies and prenatal diagnosis has been uncommonly reported (confined to cases diagnosed incidentally by flat-plate X-ray examination of the mother in late third trimester, and a case found by directed ultrasound performed in a Mendelian affected mother). Cases included 1) a young primigravida thought to be affected with Conradi-Hünermann syndrome presented at 16 weeks gestation for prenatal diagnosis and counseling. Ultrasound examination of the fetus detected assymetric limb shortness allowing the presumptive diagnosis of an affected fetus which was confirmed after delivery near term. 2) A normal 38-year-old multipara with unremarkable family history underwent routine fetal ultrasound evaluation at 18 weeks gestation. Disorganization of the spine, premature echogenicity of femoral epipheses, and frontal bossing with depressed nasal bridge were described. Neonatal examination confirmed suspicion of CH. Case 1 demonstrates the importance of solid clinical diagnosis in Mendelian malformation-affected parents for directing prenatal diagnostic efforts. Case 2 represents the first index case of CH diagnosed antenatally by ultrasound. Diagnostic clues which must be considered in establishing these diagnoses are discussed, as are some of the difficulties and limitations in antenatal counseling such cases.

Malformation syndromes caused by disorders of cholesterol synthesis

“…At the severe end, one can see early fetal loss and stillbirths with severe skeletal and internal anomalies ( 242 ). In these cases, a skeletal dysplasia, with asymmetric shortening of the long bones detected on prenatal ultrasound may suggest CDPX2, among other diagnoses ( 243 ). The ability to screen for mutations in the X-linked EBP gene in patients with suspected CDPX2 has resulted in the identifi cation of much more mildly affected individuals.…”

Chondrodysplasia punctata, tibial-metacarpal type in a 16 week fetus.

“…2 Previous ultrasonographic reports have identified both autosomal recessive rhizomelic and X-linked dominant nonrhizomelic chondrodysplasia punctata (Conradi-Hunermann). 3,4 However, we could find no reports of early ultrasonographic findings of CP-MT. Our case report shows the midtrimester ultrasono- graphic findings, along with radiologic and pathologic correlation after pregnancy termination.…”

Radiological picture of premature baby with manifestation of brachytelephalangic type chondrodysplasia punctata, myelomalacia

“…Prenatal ultrasonography and fetal MRI can also capture this group of disorders. 5,9,10 The cervical spinal cord compression and myelomalacia are better demonstrated with MRI.…”