RT Book, Section
A1 Bianchi, Diana W.
A1 Crombleholme, Timothy M.
A1 D'Alton, Mary E.
A1 Malone, Fergal D.
SR Print(0)
ID 1106399997
T1 Osteogenesis Imperfecta
T2 Fetology: Diagnosis and Management of the Fetal Patient, 2e
YR 2015
FD 2015
PB McGraw-Hill Education
PP New York, NY
SN 978-0-07-144201-5
LK obgyn.mhmedical.com/content.aspx?aid=1106399997
RD 2024/04/20
AB Key  PointsClinically  and  genetically  heterogeneous  disorder  manifested  by  bone  fragility  and  low  bone  mass.Seven  distinct  subtypes  exist.  Severity  is  as  follows:  type  II  >  type  III  >  types  IV  =  V  =  VI  =  VII  >  type  I.Most  cases  that  present  prenatally  are  types  II  or  III.  Only  10%  of  fetuses  with  type  I  have  fractures  in  utero.Other  findings  include  blue  sclerae,  abnormal  teeth,  joint  hyperlaxity,  adult-onset  hearing  loss,  and  normal  intelligence.Prenatal  sonographic  findings  include  long  bone  fractures  with  callus  formation,  limb  shortening,  poor  mineralization  of  the  skull,  and  bent  femurs.Differential  diagnosis  includes  campomelic  dysplasia,  hypophosphatasia,  and  achondrogenesis.In  90%  of  cases  there  is  a  mutation  in  one  of  the  genes  that  codes  for  type  I  procollagen,  COL1A1  or  COL1A2.Most  cases  are  dominantly  inherited.  If  parents  are  asymptomatic  there  is  a  7%  recurrence  risk  due  to  the  surprisingly  high  incidence  of  gonadal  mosaicism.