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Question 1

disturbances or abnormalities in the growth or development of bone ?

Answer 1

OSTEODYSTROPHIES

Question 2

What is the OSTEOGENESIS IMPERFECTA (Brittle Bone Disease) ?

Answer 2

hereditary disorders - caused by abnormal synthesis of Type I collagen , esulting in generalized osteopenia with increased bone fragility & susceptibility to fractures with minimal trauma

Question 3

Type II of Osteogenesis imperfecta ?

Answer 3

1- Autosomal recessive (AR)

2- is Fatal → Stillborn (dead) baby or death after birth due to multiple fractures in utero or immediately after birth

Question 4

Type I of Osteogenesis imperfecta L

Answer 4

Autosomal dominant (AD)

Question 5

ACHRONDROPLASIA is ?

Answer 5

is a hereditary disorder characterized by inhibition of the normal growth of epiphyseal cartilage plate.

Question 6

ACHRONDROPLASIA is due to mutation of ?

Answer 6

fibroblast growth factor receptor 3 (FGFR3)

Question 7

Activation of this abnormal FGFR3 lead to ?

Answer 7

inhibits proliferation of chondrocytes in the epiphyseal growth plate → short long bones.

Question 8

Long bones are short and thick of ACHRONDROPLASIA is ?

Answer 8

short limbs → Dwarfism ± bowing of the legs, and lordosis

Question 9

The skull and vertebral bones spared of ACHRONDROPLASIA ?

Answer 9

Normal size of head and trunk

Question 10

What is the pathology of OSTEOPETROSIS (Marble bone disease) ?

Answer 10

1- Increased bone density 
2- Increased tendency to fractures 
3- Decreased hematopoiesis 
4- Extramedullary hematopoiesis → hepatosplenomegaly 
4- Cranial nerve compression

Question 11

Autosomal recessive (malignant type) of OSTEOPETROSIS ?

Answer 11

• Affects infants and children
• Multiple fractures
• Early death due to anemia, infection, or hemorrhage

Question 12

Autosomal dominant (benign type) of OSTEOPETROSIS ?

Answer 12

• Affects adults
• Fractures
• Mild anemia
• Cranial nerve impingement

Question 13

developmental abnormality or benign tumor-like lesion characterized by a mixture of fibrous and woven bony tissue in the medullary region of affected bones is ?

Answer 13

Fibrous Dysplasia

Question 14

Monostotic fibrous dysplasia is

Answer 14

• accounts for 70% of cases

- involves a single bone

Question 15

Polyostotic fibrous dysplasia without endocrine dysfunction is ?

Answer 15

• accounts for 25% of cases

- involves multiple bones

Question 16

Polyostotic fibrous dysplasia with endocrinopathies (Albright syndrome) ?

Answer 16

• accounts for 3-5% of cases
• involves multiple bones
• Associated with:
• endocrine abnormalities, especially precocious puberty (in girls)
• spots café au lait spots on skin

Question 17

café au lait spots on skin is due to ?

Answer 17

Polyostotic fibrous dysplasia with endocrinopathies (Albright syndrome)

Question 18

What is the X-Ray of Fibrous Dysplasia ?

Answer 18

radiolucent ground-glass appearance