Achondroplasia

Achondroplasia
Presentation from:Juniata College


Normal Growth
Short stature
Normal or variant short stature
Pathologic short stature
Normal or variant short stature
Genetic short stature
Constitutional delay: (i.e. “late bloomer”) keep growing when others stop
Disproportionate short stature: ex: skeletal dysplasia
Metabolic bone disease
“Dwarf”
Proportionate short stature: ex: endocrine problems, Down Syndrome
“Midget”
Disproportionate short stature: diagnosis
* Upper/lower ratio (head to hip socket is upper)
o ~1.7 at birth
o ~0.95 caucasian adult/~0.85 Af. Am. Adult
* Span (fingertip to fingertip)
o Equals height up to adolescence
o After, up to 5 cm>height
* X-rays are diagnostic for skeletal dysplasias

For general characterization

* Compare
o Chronological age
o Height age (height of a person at the 50th percentile for their age)
o Bone age (ossification assessed by X-ray)
* If:
o BA=CA, genetic short stature
o BA=HA, constitutional delay
o BA HA, pathologic short stature

Achondroplasia
Hypochondroplasia
Thanatophoric dysplasia
Other causes of short stature

* X-linked hypophosphotemic rickets
o X-linked dominant (males more severely affected)(disproportionate)
* Turner Syndrome (45,X) (proportionate)
* Laron Dwarfism
o Insensitivity to growth hormone (receptor defect)/AR/proportionate S.S./squeaky voice
* Malnutrition
* Chronic disease
* Other endocrine problems

Achondroplasia.ppt