Prenatal Diagnosis of Lissencephaly Type 2 using Three-dimensional Ultrasound and Fetal MRI: Case Report and Review of the Literature

Abstract

Lissencephaly is a genetic heterogeneous autosomal recessive disorder characterized by the classical triad: brain malformations, eye anomalies, and congenital muscular dystrophy. Prenatal diagnosis is feasible by demonstrating abnormal development of sulci and gyri. Magnetic resonance imaging (MRI) may enhance detection of developmental cortical disorders as well as ocular anomalies. We describe a case of early diagnosis of lissencephaly type 2 detected at the time of routine second trimester scan by three-dimensional ultrasound and fetal MRI. Gross pathology confirmed the accuracy of the prenatal diagnosis while histology showed the typical feature of cobblestone cortex. As the disease is associated with poor perinatal prognosis, early and accurate prenatal diagnosis is important for genetic counseling and antenatal care.

In utero MR imaging in fetuses at high risk of lissencephaly

“…Advances in ultrasonography may change this limitation, and two recent publications have suggested that improved diagnostic accuracy with ultrasound is possible. 11,12 Our present study lends support to that suggestion, as the 3/23 (13%) fetuses with lissencephaly did not have the diagnosis made on ultrasonography, although borderline ventriculomegaly was found in 1 case. The inability to detect (or raise the possibility of) lissencephaly on ultrasound, coupled with the rarity of the disorder (prevalence approximately 1 : 100000), makes it virtually impossible to perform a prospective study of diagnostic accuracy of antenatal imaging methods in de novo cases.…”

A prenatal case of lissencephaly with cerebellar hypoplasia: New mutation in RELN gene

“…Thus, US findings of lissencephaly can be theoretically observed in experts’ hands from the early second trimester 8 . However, if no indirect signs are observed, such as microcephaly and/or ventriculomegaly, lissencephaly is then often not suspected until the routine scan of the third trimester (30–32 weeks of GA) as this is the best period to study the cortical gyration 9 . Once a lissencephaly is suspected, proposing a fMRI is mandatory if available.…”

“…8 However, if no indirect signs are observed, such as microcephaly and/or ventriculomegaly, lissencephaly is then often not suspected until the routine scan of the third trimester (30-32 weeks of GA) as this is the best period to study the cortical gyration. 9 Once a lissencephaly is suspected, proposing a fMRI is mandatory if available. Fetal cerebral MRI gives the final prenatal diagnosis, since it provides further details about the cerebral parenchyma as it has a better contrast resolution than US.…”

Abnormalities of the Fetal Central Nervous System: Prenatal US Diagnosis with Postnatal Correlation

“…Specifically, assessment of fetal sylvian fissure development or operculization at prenatal US has been described as a measure of gyration and an early indicator of cortical dysplasia (27,28). Finally, the use of three-dimensional (3D) US with surface rendering technique has been proposed as a means of aiding the diagnosis of lissencephaly in pregnancy (29).…”