Achondroplasia

Overview

• Achondroplasia, implying absent cartilage formation is a type of skeletal dysplasia which are a heterogeneous group of disorders characterized by intrinsic abnormalities in the growth or remodelling of cartilage and bone. They affect the skull, spine, and extremities in varying degrees. 

• The characteristic feature of achondroplasia is a disproportionately short stature (dwarfism). The short stature mainly results from shortening of the limbs with proximal segments affected disproportionally, a phenotype referred as rhizomelia.

•  Achondroplasia is the most common type of short-limb disproportionate dwarfism. More than 95% of patients have the same point mutation in the gene for fibroblast growth factor receptor 3 (FGFR3) which is inherited in an autosomal dominant pattern and more than 80% are new mutations. 

• The Igenomix Achondroplasia Precision Panel can be used to make a directed and accurate differential diagnosis of disproportionately short stature ultimately leading to a better management and prognosis of the disease. It provides a comprehensive analysis of the genes involved in this disease using next-generation sequencing (NGS) to fully understand the spectrum of relevant genes involved.  

Indication

The Igenomix Achondroplasia Precision Panel is indicated for those patients with a suspected clinical diagnosis of achondroplasia presenting with the following manifestations: 

• Disproportionate short stature 
• Macrocephaly with frontal bossing  
• Prominent mandible 
• Shortening of the arms with redundant skin folds 
• Limitation of elbow extension 
• Delayed gross motor development 
• Brachydactyly 
• Exaggerated lumbar lordosis  
• Thoracolumbar kyphosis 

Clinical Utility

The clinical utility of this panel is: 

• The genetic and molecular confirmation for an accurate clinical diagnosis of a symptomatic patient.  
• Early initiation of treatment with a multidisciplinary team that includes supportive treatment in the form of medical care, early surgical care, rehabilitation and physical therapy.   
• Prenatal detection of achondroplasia for a directed obstetric and perinatal treatment of affected infants. 
• Risk assessment of asymptomatic family members according to the mode of inheritance. 

Genes & Diseases

*Inheritance: AD: Autosomal Dominant; AR: Autosomal Recessive; X: X linked; XLR: X linked Recessive; Mi: Mitochondrial; Mu: Multifactorial.  

**Number of clinically relevant mutations according to HGMD