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mobility and reduced pain and an improved quality of
life, we have realized that OI severity is significantly
modified by bisphosphonate treatment. Many groups
have reported their experience with bisphosphonates
uniformly confirming those observations. The largest
body of work has come from the Shriner's Hospital in
Montreal.
76
Coordinators of multidisciplinary care for
OI patients will soon be able to report 20 years' expe-
rience of the syndrome of pamidronate modified OI.
Patients prior to bisphosphonate therapy experienced
a high degree of fracture, progressive deformity and
wheelchair use (
Figure 1.2
). Bisphosphonate modi-
ied OI is a very different disorder, resulting in far less
deformity and markedly reduced fracture frequency
particularly when started in patients who are severely
affected in the perinatal period (
Figure 1.3
).
FUTURE RESEARCH
There remains a percentage of patients with OI in
whom the molecular mechanisms have yet to be eluci-
dated. It is already clear that the phenotype and gene
frequencies of various genetic forms of OI differ in vari-
ous world populations such that in populations where
there is either a high frequency of consanguinity or
geographic boundaries which favor a founder effect of
recessive mutations, autosomal recessive forms of OI
may be more prevalent.
FIGURE 1.2
Boy with progressively deforming OI-COL1A2 from
pre-pamidronate era showing short stature and wheelchair use for
ambulation.
References
[1] Ekman O. Descriptionem casus aliquot osteomalacia sistens.
Upsala; 1788.
[2] Vrolik W. Tabulae et illustrandam embryogenesin homines et
mammalium, tam naturalem quam abnormem. Amsterdam; 1849.
[10]
[11]
FIGURE 1.3
Bisphosphonate modified OI in two children with OI
type III.
