Parental serum alkaline phosphatase activity as an auxiliary tool for prenatal diagnosis of hypophosphatasia.
OBJECTIVE
The objective of this study is to clarify the usefulness of parental alkaline phosphatase (ALP) for prenatal diagnosis of hypophosphatasia (HPP).


METHODS
Maternal (m) and paternal (p) ALP values were measured in 77 cases from a multicenter cohort (fetal skeletal dysplasia forum in Japan) of cases with short limbs on ultrasonography during pregnancy. After birth, X-rays, cord blood ALP, and gene analysis were evaluated to achieve an exact diagnosis. The screening usefulness of ALP was examined retrospectively.


RESULTS
Seventeen cases were eventually diagnosed as HPP and 60 as not HPP; the overall mean m-ALP and p-ALP (standard deviation) values were 133.4 (53) versus 197 (69) IU/L and 149.6 (71.8) versus 231 (61.4) IU/L (p < 0.001). Receiver operating characteristic curve analysis showed that the optimal m-ALP and p-ALP cutoff values were 123 and 165 IU/L, respectively. Presence of at least one of the m-ALP or p-ALP values abnormally low had a sensitivity, specificity, and positive predictive values of 82% (14/17), 93%, and 78%, respectively, for the diagnosis of HPP.


CONCLUSIONS
Parental ALP measurement might be an auxiliary tool to hone in the prenatal diagnosis of fetal HPP. © 2017 John Wiley & Sons, Ltd.
Department of Fetal-Maternal Medicine, Nagara Medical Center, Gifu, Japan.
Yuichiro
http://orcid.org/0000-0001-7352-4954
Y
Takahashi
Department of Obstetrics and Gynecology, Hyogo College of Medicine, Nishinomiya, Japan.
Hideaki
H
Sawai
Department of Obstetrics, Miyagi Children's Hospital, Sendai, Japan.
Jun
J
Murotsuki
Department of Obstetrics and Gynecology, Elm Josei Clinic, Aomori, Japan.
Shuhei
S
Satoh
Department of Obstetrics and Gynecology, Hokkaido University, Sapporo, Japan.
Takahiro
T
Yamada
Department of Obstetrics and Gynecology, Aichi Children's Health and Medical Center, Aichi, Japan.
Hiromi
H
Hayakawa
Department of Obstetrics and Gynecology, Kurume University School of Medicine, Fukuoka, Japan.
Yutaka
Y
Kouduma
Department of Obstetrics and Gynecology, Yamaguchi Grand Medical Center, Yamaguchi, Japan.
Masakatsu
M
Sase
Division of Clinical Genetics, Nippon Medical School Hospital, Tokyo, Japan.
Atsushi
A
Watanabe
Department of Radiology, National Center for Child Health and Development, Tokyo, Japan.
Osamau
O
Miyazaki
Department of Radiology, Tokyo Metropolitan Kiyose Children's Hospital, Tokyo, Japan.
Gen
G
Nishimura
D000469:Alkaline Phosphatase / Q000097:blood*; D015331:Cohort Studies; D004252:DNA Mutational Analysis / Q000379:methods; D005260:Female; D005312:Fetal Blood / Q000737:chemistry; D005820:Genetic Testing; D005865:Gestational Age; D006801:Humans; D007014:Hypophosphatasia / Q000097:blood / Q000175:diagnosis* / Q000235:genetics; D008297:Male; D010290:Parents; D011247:Pregnancy; D011296:Prenatal Diagnosis / Q000379:methods*; D012189:Retrospective Studies
D000469:Alkaline Phosphatase