The genetic aspect and morphological appearance of achondrogenesis

Abstract

Achondrogenesis (ACG) is a number of disorders that are the most severe form of congenital chondrodysplasia characterized with bones and cartilage malformation. Generally, characteristic of ACG is a small body, short limbs, and other skeletal abnormalities. As a result of infants with ACG their serious health problems, usually born prematurely, are stillborn, or die shortly after birth from respiratory failure. Currently 3 type variants of ACG such as ACG-1A, ACG-1B and ACG-2. ACG-1A appears to be autosomal recessive (AR), with thyroid hormone receptor interactor 11 (TRIP11) gen mutation, while ACG1B also appears to be AR, with diastrophic dysplasia sulfate transporter or DTDST (SLC26A2) gen mutation. ACG-2 is caused by autosomal dominant (AD), with type 2 collagen (COL2A1) gen mutation. ACG-1A had characterizid such as physis abnormal, vertebral bodies with unossified or smal and oval, skull poorly ossified, periodic acid–Schiff (PAS) stain positive chondrocyte inclusions finding in long bones. ACG-1B had physis abnormal, vertebral bodies with unossified or smal and oval, skull ossified, perichondrocyte collagen rings finding in long bones. ACG-2 also had physis abnormal, metaphyseal cupping, vertebral bodies with unossified or small and oval, enlarged chondrocyte lacunae.

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

“…Presumably, the consequences of this event are the processes of maturation and differentiation of chondrocytes and endochondral bone formation, which are severely affected 27 . Presence of inclusion bodies, hypertrophic vacuolated chondrocytes and disorganized chondrocyte plaques has also been described [25][26][27][28][29] ; all these findings are similar to those observed in the proposita's biopsy, except that inclusion bodies were not observed, a finding that has not been previously described. The absence of inclusion bodies can be explained by the reduced amount of intracellular collagen and proteoglycans, which is conclusive of the severe endochondral formation disorder.…”

Nuevo subtipo de acondrogénesis familiar tipo IA (Houston-Harris)

“…Presumiblemente, las consecuencias de este evento son los procesos de maduración y diferenciación de los condrocitos y la formación de hueso endocondral, que se ven gravemente afectados 27 . También se ha descrito la presencia de cuerpos de inclusión, condrocitos vacuolados hipertróficos y placas desorganizadas de condrocitos [25][26][27][28][29] ; todos estos hallazgos son similares a los encontrados en la biopsia de la proposita, excepto que no se observaron cuerpos de inclusión, hallazgo que no ha sido descrito previamente. Los cuerpos de inclusión ausentes pueden explicarse por la cantidad reducida de colágena y proteoglucanos intracelularmente, lo cual es concluyente del grave trastorno de la formación endocondral.…”