Diagnostic ultrasound ( PDFDrive )

1394 PART IV Obstetric and Fetal Sonography
TABLE 40.5 Classiication of Osteogenesis Imperfecta by Type
Type Clinical Features Prenatal Findings Prognosis Inheritance Molecular
Abnormalities
I
II
III
IV
Normal stature, little or no
deformity, blue sclera,
hearing loss in 50% of cases
Type IA: normal teeth
Type IB: opalescent teeth
Lethal; hypomineralization of
the skull, beaded ribs,
compressed femurs, marked
long-bone deformity, blue
sclera, triangular face,
platyspondyly
Usually with long-bone
fractures; moderate
deformity at birth but
progressively deforming
bones; triangular face, blue
sclera, opalescent teeth,
hearing loss, short stature
Mild to moderate bone
deformity and variable short
stature; opalescent teeth in
type IVB; hearing loss occurs
in some families; white
sclera
Occasionally, short
and bowed long
bones and
fractures
Severe micromelia
Rib and long-bone
fractures
Hypomineralization
of skull
Occasionally, short
and bowed long
bones and
fractures
Occasionally, short
and bowed long
bones and
fractures
Fair Autosomal dominant Nonsense or
frameshift
mutations in
COL1A1 gene
Lethal
Wheelchair
bound,
nonambulatory
Fair
Autosomal dominant
(new mutations)
Parental gonadal
mosaicism
responsible for
recurrence
Autosomal dominant
Parental gonadal
mosaicism
responsible for
recurrence
Autosomal recessive
(rare)
Autosomal dominant
Parental gonadal
mosaicism
responsible for
recurrence
Glycine
missense
mutation in
COL1A1 or
COL1A2
genes
Glycine
missense
mutation in
COL1A1 or
COL1A2
genes
Glycine
missense
mutation in
COL1A1 or
COL1A2
genes
Modiied from Sillence DO, Senn A, Danks DM. Genetic heterogeneity in osteogenesis imperfecta. J Med Genet. 1979;16:101-116. 70
A
B
FIG. 40.20 Facial Proile: Normal Versus Osteogenesis Imperfecta (OI). (A) Normal proile of a 14-week fetus. (B) Facial proile of a 14-week
fetus affected by OI. Note the absent calvarial and nasal ossiication and micrognathia.