Prenatal diagnosis in pregnancies at risk for Joubert syndrome by ultrasound and MRI.
OBJECTIVE
To describe the prenatal imaging findings in fetuses at risk for Joubert syndrome (JS), review the literature and propose a protocol for prenatal diagnosis of JS using ultrasound and MRI.


METHODS
We reviewed prenatal ultrasound and fetal MRI studies in two pregnancies at 25% recurrence risk for JS and correlated these findings with gross neuropathology in one affected fetus.


RESULTS
While abnormalities such as occipital encephalocele or enlarged cisterna magna have been identified before mid-trimester, the definitive diagnosis of JS, based on core cerebellar findings, has only been possible after 17 weeks' gestation.


CONCLUSIONS
With longitudinal monitoring, it is possible to diagnose JS in at-risk pregnancies before 24 weeks' gestation. On the basis of our data and review of the literature, we propose a protocol for monitoring pregnancies at risk for JS, utilizing serial ultrasounds combined with fetal MRI at 20-22 weeks' gestation to maximize the accuracy of prenatal diagnosis.
Doherty
Dan
D
University of Washington/Children's Hospital and Regional Medical Center, Department of Pediatrics, Seattle, WA, USA. ddoher@u.washington.edu
Glass
Ian A
IA
Siebert
Joseph R
JR
Strouse
Peter J
PJ
Parisi
Melissa A
MA
Shaw
Dennis W W
DW
Chance
Phillip F
PF
Barr
Mason
M
Nyberg
David
D
D001259:Ataxia; D002531:Cerebellum / Q000002:abnormalities*; D005133:Eye Movements; D005260:Female; D005865:Gestational Age; D006801:Humans; D008607:Intellectual Disability; D008279:Magnetic Resonance Imaging; D008297:Male; D011247:Pregnancy; D011296:Prenatal Diagnosis / Q000379:methods*; D012307:Risk Factors; D013577:Syndrome; D016216:Ultrasonography, Prenatal