Skeletal Dysplasia Flashcards
When should we suspect skeletal dysplasia?
disproportion, joint abn (limitation of motion), bone deformity (bowing, thumb deficiency), others
dysplasia is:
bad growth caused by intrinsic bone abn
dysostosis is:
deformity or maldevelopment of a single bone or body segment
dystrophy is:
deformities caused by metabolic or nutritional problems
chondrodystrophy is:
disturbance that includes various systems including bone
chondrodysplasia:
generalized disturbance of bone modeling
how are bone disorders classified?
anatomically, clinical features, radiographically, molecular/pathogenic
When is bone remodeling occuring?
throughout life, most significant in 1st year
Which bone ossifies first?
clavicle
which group of bones ossify over time and are often used for bone age? first and last?
wrist
capitate (1st year)
pisiform (10th year)
what is the most common type of dwarfism?
achondroplasia
the disproportionate short stature is characterized by:
discrepancies in limb and trunk length
what gene is associated with achondroplasia?
FGFR3
what are some radiological findings of achondroplasia?
narrowing of the space in lumbar spine
short vertebral bodies
square iliac wings
radiolucency of the proximal femora (ends of bones don’t show up as well on X-ray)
when is bone foreshortening typically seen on U/S
20-24wks
what are the molecular genetics of achondroplasia?
AD pattern
>80% de novor ate
correlated with advanced paternal age
100% penetrance
rhizomelic shows:
short proximal segments (humerus, femur)
mesomelic shows:
short middle segments (radius, ulna, tibia, fibula)
acrocentric limbs shows:
short distal segments (digits)
what type of OI is most severe? characteristics?
type 2
prenatal fractures, poor bone mineralization, multiple healing fractures
What genes are associated with OI?
COL1A1 and COL1A2
what is the recurrence risk associated with OI if more than one affected child has been born to unaffected parents?
28%
osteoporosis, achondrogenesis, Ellis-van Creveld syndrome, Rhizomelic chondrodysplasia, disatrophic dysplasia, and others are all examples of disorders with:
increased bone density
