Achondroplasia

ACHONDROPLASIA

• The commonest form of abnormal short stature.About 1 in 25,000 births.
• Severe, disproportionate shortening of limb bones may be diagnosed by x-ray before birth.
• The main pathology lies in the abnormal endochondral longitudinal growth.
• Autosomal dominant : Point mutation in the gene coding for FGF receptor 3 (key role in endochondral cartilage growth).
• Adult height is usually around 125 cm in females and 132 cm in males

CLINICAL FEATURES

• Rhizomelic dwarfism
• Proximal part of limb is shorter
• Macrocephaly
• Frontal bossing (broad forehead)
• Midface hypoplasia
• Bradydactyly (short digits)
• Trident hands
• Genu varum
• Thoracolumbar kyphosis
• Foramen magnum stenosis
• Champagne Glass Pelvis
• Inverted V In Distal Femur Physis