Flashcards in 18. Achondroplasia Deck (20)
failure of longitudinal bone growth ( endohondral ossification ) --> short limbs
Short extremities with normal sizes head and chest ( large head RELATIVE to limbs )
Achondroplasia --> membranous ossification
not affected ( normal head and chest )
Achondroplasia --> pathophysiology
constitutive activation of FGFR3 --> inhibits chondrocyte proliferation --> impaired cartilage proligeration in growth plate --> impaired endochondtral ossification
mutation in achondriplasia
FGFR3 ( activation )
Achondroplasia --> sporadic vs inherited mutation
Achondroplasia --> inherited type - mode of inheritance
AD ( if homozygosity --> lethal )
Achondroplasia is the MCC of
a condition of short stature
MCC of Dwardism
achondroplasia - mental function
achondroplasia - sporadic mutation frequency is increased with
• Achondroplasia is an autosomal ____ (dominant/recessive) trait. The majority (85%) of cases are ____ (inherited/sporadic).
• You see a 4-year-old boy with achondroplasia and note he has short limbs. Why is this seen in patients with achondroplasia?
The underlying problem in patients with achondroplasia is failure of long bone growth (endochondral ossification)
• You see a 4-year-old boy with achondroplasia and note that he has short limbs, but an appropriate head circumference. How is this possible?
Patients with achondroplasia have defects in endochondral, not membranous, ossification—the skull and axial bones are unaffected
• What is the result of a fibroblast growth factor receptor 3 (FGFR3) mutation in patients with achondroplasia?
The gene is active, inhibiting chondrocyte proliferation & cannot form cartilaginous model for endochondral ossification of long bones