Prenatal diagnosis of thanatophoric dysplasia by 3-D helical computed tomography and genetic analysis.
OBJECTIVE
We report the first case of thanatophoric dysplasia (TD) successfully diagnosed in utero by a combination of 2-D ultrasound, computed tomography (CT) 3-D imaging and genetic analysis at 26 weeks' gestation.


METHODS
Prenatal sonographic examinations performed at 23 weeks' gestation revealed micromelic shortening of the limbs, reduced thoracic cavity and a presence of cloverleaf skull deformity. Based on these findings, a lethal form of skeletal dysplasia was suspected and a helical CT imaging with 3-D reconstruction depicted skeletal abnormalities which suggested TD. The prenatal diagnosis was affirmed on amniotic fluid cells by DNA mutation analysis of the fibroblast growth factor receptor 3 gene.


RESULTS
A missense mutation (tyrosine 373 to cysteine) was detected, and was diagnosed as TD type I.


CONCLUSIONS
Helical CT imaging with 3-D reconstruction and molecular testing are useful adjuncts to 2-D ultrasonography in the diagnosis of lethal skeletal dysplasias, allowing for appropriate perinatal support including genetic counseling.
Tsutsumi
Seiji
S
Department of Obstetrics and Gynecology, Yamagata University School of Medicine, Yamagata, Japan. stsutsumi@med.id.yamagata-u.ac.jp
Sawai
Hideaki
H
Nishimura
Gen
G
Hayasaka
Kiyoshi
K
Kurachi
Hirohisa
H
D000328:Adult; D001132:Arm / Q000002:abnormalities / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007866:Leg / Q000002:abnormalities / Q000000981:diagnostic imaging; D020125:Mutation, Missense; D011247:Pregnancy; D047928:Premature Birth; D011296:Prenatal Diagnosis / Q000379:methods*; D051498:Receptor, Fibroblast Growth Factor, Type 3 / Q000235:genetics*; D012886:Skull / Q000002:abnormalities / Q000000981:diagnostic imaging; D013796:Thanatophoric Dysplasia / Q000000981:diagnostic imaging* / Q000235:genetics*; D036542:Tomography, Spiral Computed; D014463:Ultrasonography
C496365:FGFR3 protein, human; D051498:Receptor, Fibroblast Growth Factor, Type 3