Achondrogenesis is a rare genetic skeletal dysplasia was first described in 1952 by Marco Fraccaro. It is depicted by shortened limb, short trunk and a narrow chest. It affects both males and females in equal numbers. The disorder is an inherited one which means it is passed down through families.
It is an autosomal recessive disorder caused by growth hormone deficiency.
Type 1A- It is caused due to loss of function mutation in TRIP11 gene that forms Golgi-Microtubule-Associated Protein-210 (GMAP-210. MAP-210 is found at the cis side of the Golgi apparatus and most likely responsible for the movement of proteins from the endoplasmic reticulum to the Golgi apparatus but with this defect, it is unable to do so and therefore the proteins remain inside the Endoplasmic reticulum and subsequently cell death.
Type 1B- is the most severe of a spectrum of skeletal disorders caused by mutations in the SLC26A2 gene.
Type II- is caused by autosomal dominant change in the COL2A1 gene. Apart from skeletal abnormalities, severe pulmonary hypoplasia which is believed to be related directly to the underlying pathology in the expression of collagen is linked with achondrogenesis.
- Mesomilic dwarfism
- Disproportionately large head
- Poorly formed spine
- Closure of cleft palate
- Corneal clouding
- There is lung hypoplasia, bell shaped cage and a short and flared thorax.
- The abdomen is protuberant
Achondrogenesis is diagnosed by the ultrasonographic signs included severe short limb mesomelic dwarfism, large head with decreased ossification, and lack of vertebral ossification. Examination of tissue samples under microscope (Histology), biochemical tests and molecular genetic tests can be further used to confirm the diagnosis.
- Genetic counselling and psychosocial support is recommended for families with an affected child.
- Constant medical checks before and immediately after conception is confirmed.
- Routine ultrasound screening made early detection and timely management possible.