Achondrogenesis

Abstract

In this issue of Pediatric and Developmental Pathology, Aigner and colleagues report a detailed investigation of cartilage matrix changes in a 14-week fetus with achondrogenesis type IA. The changes reported differ from matrix alterations observed in achondrogenesis types IB or II and provide insight into the phenotypic and genotypic differences within this group of skeletal dysplasias.

Diagnosis of Prenatal-Onset Achondrogenesis Type II by a Multidisciplinary Assessment: A Retrospective Study of 2 Cases

“…Over several decades, owing to the considerable phenotypic variability, achondrogenesis type I and II have been distinguished based on clinical, radiologic, and histopathological features [10]. In our experience with the prenatal sonographic diagnosis of achondrogenesis, the fetal femur length was the best biometric parameter to distinguish achondrogenesis from other skeletal dysplasias.…”

New subtype of familial achondrogenesis type IA (Houston-Harris)

“…The diagnosis can also be established by sequencing. For patients with ACG2, mutations are found in COL2A1 6,10 ; in ACG1B, in the DTDST gene 3,5,9,[12][13][14][15][16][17] . In the search for an implicated gene for ACG1A, Smits et al 13 found that mice with GMAP-210 deficiency died with a phenotype similar to ACG1A.…”

“…These three variants are lethal in utero. Radiological and histopathological characteristics enable differential diagnosis; between types I and II it is easier, since they are clinically different [3][4][5][6] .The present work aims to be the first report of a new ACG1A subtype with a previously unreported mode of inheritance, which is not autosomal recessive, as well as some not previously observed histopathological findings.…”

“…ACG has a global frequency of 1-50,000. In the case of ACG1A, mutations in the TRIP11 gene have been reported, but without being conclusive as a single cause [3][4][5][6][7][8] . These three variants are lethal in utero.…”

Visceral manifestations of hypochondrogenesis

“…As with other lethal infantile bone dysplasias, diagnosis of this spectrum can usually be made by radiography alone in the clinical setting, and an expensive molecular confirmation is of little value [5]. At the histological level, the diagnosis is supported by the demonstration of chondrocytes containing ballooned lacunae in the zones of endochondrial ossification [12].…”