Developmental Disorders

Question 1

Define osteogenesis imperfecta and how it occurs.

Answer 1

A rare group of genetic disorders mainly affecting bone.
Defect in the maturation and organisation of type 1 collagen
(AKA Brittle bone disease)

Question 2

True/False: The majority of cases of osteogenesis imperfecta are autosomal dominant.

Answer 2

True

Question 3

Describe the clinical presentation of autosomal dominant osteogenesis imperfecta.

Answer 3

Multiple fragility fractures of childhood
Short stature with multiple deformities
Blue sclerae
Dentinogenesis imperfecta
Loss of hearing

Question 4

Describe the clinical presentation of autosomal recessive osteogenesis imperfecta.

Answer 4

Either fatal in perinatal period or associated with spinal deformity

Question 5

What would you see on X-ray of osteogenesis imperfecta?

Answer 5

Bones are gracile with thin cortices and osteopenia
Mild cases have normal x-ray with history of low energy fractures

Question 6

True/False: Skeletal dysplasia = short stature (dwarfism)

Answer 6

True - DONT USE DWARFISM

Question 7

What is Duchenne Muscular Dystrophy and how does it arise?

Answer 7

Rare X-linked disorder that leads to progressive muscle wasting.
Defect in dystrophin gene involved in calcium transport = muscle weakness

Question 8

What is a typical clinical presentation of Duchenne muscular dystrophy?

Answer 8

Progressive muscle weakness
By age 10 or so patient can no longer walk
By age 20 progressive cardiac and resporatory failure develop

Question 9

What investigations can you perform to diagnose Duchenne’s muscular dystrophy?

Answer 9

Raised serum creatinine phosphokinase
Abnormalities on muscle biopsy

Question 10

What is cerebral palsy?

Answer 10

Persisting qualitative motor disorder appearing beforethe age of 3 due to non-progressive damage to the brain occuring before the growth of the central nervous system is complete.

Question 11

List some potential causes of cerebral palsy.

Answer 11

Genetic issues
Brain malformation
Intrauterine infection in early pregnancy
Prematurity
Intra-cranial haemorrhage
Hypoxia during birth

Question 12

Define developmental dysplasia of the hip.

Answer 12

Dislocation/subluxation of the femoral head during the perinatal period which affects the subsequent development of the hip joint

Question 13

Define Perthes disease

Answer 13

Idiopathic osteochondrosis of the femoral head