Achondroplasia

Question 1

What is the commonest form of short-limbed dwarfism?

Answer 1

Achondroplasia

Question 2

Inheritance

Answer 2

Autosomal dominant

Question 3

Relation of Achondroplasia with paternal age

Answer 3

Incidence increases with paternal age

Question 4

Pathophysiology

Answer 4

Epiphyseal growth cartilage fails

Normal bone formation and repair >> so, NO increased risk of fracture

Question 5

Homozygote of Achondroplasia

Answer 5

Fatal

Question 6

Stature of Achondroplasia

Answer 6

​Short stature (the commonest form of short-limbed dwarfism)

Short due to- >>

• Short limbs

​Spinal length is normal/maintained

Question 7

Facial feature in Achondroplasia

Answer 7

Fromtal bossing

Mid-face hypoplasma

Question 8

Spinal feature in Achondroplasia

Answer 8

Exaggregated lumbar lordosis

Progressive narrowing of the inter-pedicular distance from top to bottom (reverse of normal)

Question 9

Limb features in Achondroplasia

Answer 9

Limited elbow extension

Trident-like hands

Fingertips may only come down to the iliac crest

Shortness of the limbs (often most marked proximally)

The limbs apear broad with deep creases

Question 10

Diagnosis

Answer 10

It is diagnosed radiographically at birth

(or become obvious within the first year with disparity between large skull, normal trunk length, short limbs)

Question 11

X-rays of long bone in Achondroplasia

Answer 11

Metaphyseal irregularity

Flaring in the long bones

Late-appearing irregular epiphyses

Question 12

Pelvic feature in Achondroplasia

Answer 12

Anterior-posterior diameter: narrow

Sacro-iliac notches: deep

Iliac wings: short

Question 13

Fertility

Answer 13

Usually normal

(NOT subfertile/infertile)