TY  - CHAP
M1  - Book, Section
TI  - Hypophosphatasia
A1  - Bianchi, Diana W.
A1  - Crombleholme, Timothy M.
A1  - D'Alton, Mary E.
A1  - Malone, Fergal D.
PY  - 2015
T2  - Fetology: Diagnosis and Management of the Fetal Patient, 2e
AB  - Key  PointsRare  hereditary  metabolic  bone  disorder  characterized  by  deficient  activity  of  the  tissue-nonspecific  isoenzyme  of  alkaline  phosphatase  (TNSALP).Incidence  is  1  in  100,000  births  in  most  ethnic  groups  but  1  in  2500  in  Canadian  Mennonites.Two  forms  present  perinatally:  severe  (lethal)  and  benign,  which  resolves  spontaneously.In  the  severe  form  sonographic  findings  include  increased  nuchal  translucency  measurement,  undermineralized  skull,  shortened,  bent,  fixed  limbs  with  decreased  echogenicity,  and  lack  of  ossification  of  vertebral  bodies,  neural  arches,  and  hands.  The  benign  perinatal  form  presents  with  symmetric  bowing  of  long  bones.Differential  diagnosis  includes  anencephaly,  osteogenesis  imperfecta  types  II  and  III,  thanatophoric  dysplasia,  campomelic  dysplasia,  achondrogenesis,  and  cleidocranial  dysplasia.Amniocentesis  should  be  offered  to  rule  out  anencephaly,  confirm  fetal  karyotype,  assay  alkaline  phosphatase  activity,  and  check  for  DNA  mutation(s).Causative  gene  is  TNSALP.Severe  form  is  recessively  inherited  with  two  mutations.  Milder  form  is  dominantly  inherited  with  one  mutation.Genetic  consultation  and  counseling  are  indicated.  
SN  - 
PB  - McGraw-Hill Education
CY  - New York, NY
Y2  - 2024/04/24
UR  - obgyn.mhmedical.com/content.aspx?aid=1106400302
ER  -