Term
| What is the relative frequency of skeletal dysplasia in births? |
|
Definition
|
|
Term
| Why is the incidence of skeletal dysplasia probably an underestimate? |
|
Definition
| becuase many dysplasias are not identified until after birth |
|
|
Term
| What is locus heterogeneity? |
|
Definition
| when a disease can be caused by a mutation on a gene in different loci |
|
|
Term
| What is the paternal age effect? |
|
Definition
| the chance of mutation and passing on the condition is more likely as the father ages |
|
|
Term
| What is gonadal mosacism? |
|
Definition
| when there are two populations of cells in the gamates |
|
|
Term
| Which type of osteogenesis imperfecta is fatal at birth? |
|
Definition
|
|
Term
| What is the common clinical presentation of a patient with OI type I? |
|
Definition
blue sclerae (100% penetrance)
loss of hearing in adolescence
bone fragility |
|
|
Term
| What is the mechanism of OI type I? |
|
Definition
there are no alpha 1 chains made so there is a reduction of type I procollagen by 50%
the 50% of procollagen produced is normal |
|
|
Term
| What is the penetrance of blue sclerea in OI type I? |
|
Definition
|
|
Term
| What type of inheritence are the Osteogenesis Imperfecta? |
|
Definition
AD mostly except for
type III which can be both |
|
|
Term
| What is the mechanism of OI in type II? |
|
Definition
| there is a mutation in the gene for procollagen type I near the C-terminal domain |
|
|
Term
| What is the reason for recurance in families of OI type II births? |
|
Definition
|
|
Term
| What are the clinical manifestations of OI III? |
|
Definition
short stature
extreme bone fragility |
|
|
Term
| What is the mechanism of OI type III? |
|
Definition
| mutation in procollagen chain near N-terminal domain |
|
|
Term
| What is true of the clinical manifestations of OI type IV? |
|
Definition
it does not present with the typical presentation of OI type I
continuous dentinogenesis imperfecta is present |
|
|
Term
| What is the mechanism for OI type IV? |
|
Definition
| there is a disruption in the helix formation making it unavailable for bone |
|
|
Term
| Which OI type does not present with typical OI type I manifestations (blue sclerea and hearing loss)? |
|
Definition
|
|
Term
| Which OI type presents with osteoporosis symptoms? |
|
Definition
|
|
Term
| Which OI has continuous dentinogenesis imperfecta? |
|
Definition
|
|
Term
| Which OI presents with short stature? |
|
Definition
|
|
Term
| What is the treatment for OI types I, III, IV? |
|
Definition
rehab
Ortho care to prevent/fix fractures
growth hormone
bisphosphates (Cyclic IV pamidronate)
|
|
|
Term
| What is cyclic IV pamidronate? |
|
Definition
a bisphosphate
treatment for OI I, III, IV |
|
|
Term
| What is the most common form of skeletal dysplasia? |
|
Definition
|
|
Term
| What is the general underlying problem in chondrodysplasia disorders? |
|
Definition
| FGFR3 mutation leading to long bone cartilage development disturbance in the epiphyseal plate |
|
|
Term
| What is the most common lethal skeletal dysplasia? |
|
Definition
|
|
Term
| What is the expected IQ and life expectancy for a patient with acondroplasia? |
|
Definition
| normal IQ, normal life expectancy |
|
|
Term
| What is true of the hand and head in achondroplasia? |
|
Definition
| trident hand and large head |
|
|
Term
| What is the reason for death in Thanatophoric dysplasia? |
|
Definition
|
|
Term
| What is the most common cause of death in achondroplasia in infancy? |
|
Definition
|
|
Term
| What occurs to the spine in acondroplasia? |
|
Definition
|
|
Term
| What do achondroplasia patients have a tendency to become if they dont watch their food intake? |
|
Definition
|
|
Term
| What occurs to the proximal long bones in achondroplasia? What is this called? |
|
Definition
femur and humerous shorten
Rhizomalic |
|
|
Term
|
Definition
| shortening of proximal long bones |
|
|
Term
| What is the outcome of a homozygote for achondroplasia? |
|
Definition
|
|
Term
| What parents can you screen for in achondroplasia? |
|
Definition
| those with the disease obviously not those that occur due to mutation |
|
|
Term
| What disease is largly effected by the paternal age effect? |
|
Definition
|
|
Term
| How can the diagnosis of achondroplasia be made at birth? |
|
Definition
|
|
Term
| What genetic characteristic of achondroplasia helps to increase it being the most common skeletal dysplasia? |
|
Definition
|
|
Term
| WHat is the treatment for achondroplasia? |
|
Definition
cervical stability
limb lengthenging
prevent obesity
treat respiratory problems |
|
|
Term
| How does hypochondroplasia compare to acondroplasia in severity? |
|
Definition
| hypochondroplasia is less severe |
|
|
Term
| WHat is the IQ of a hypochondroplasia patient? |
|
Definition
|
|
Term
| When is the diagnosis made for achondroplasia and hypochondroplasia usually? |
|
Definition
achondroplasia birth
hypochondroplasia in childhood |
|
|
Term
| Why are only 70% of the mutations found in hypochondroplasia at FGFR3? |
|
Definition
| because there is locus heterogeniety |
|
|
Term
| What are the majority of new cases of hypochondroplasia caused by? |
|
Definition
|
|
Term
| What is the mechanism in both acondroplasia and hypochondroplasia? |
|
Definition
| mutated FGFR3 causes the condrocyte to not mature |
|
|
Term
| How do you treat the spinal stenosis in hypochondroplasia? |
|
Definition
|
|
Term
| How is thanatophoric dysplasia diagnoised? When? |
|
Definition
untrasound
2nd/3rd trimester |
|
|
Term
| What are the two subtypes of thanatophoric dysplasia? |
|
Definition
TD1 (intra/extracellular mutation)
TD2 (Tyrosine Kinase) |
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