Role of MR Imaging in Prenatal Diagnosis of Pregnancies at Risk for Joubert Syndrome and Related Cerebellar Disorders

Saleem, Sahar N.; Zaki, Maha S.

doi:10.3174/ajnr.a1867

Cited by 47 publications

(46 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The following inclusion criteria were used: (1) postnatal diagnosis (Subjects 4-5): the ''molar tooth sign'' characterized by cerebellar vermis hypoplasia and thick, horizontally oriented superior cerebellar peduncles; (2) prenatal diagnosis (Subjects 1-3): The molar tooth sign is not consistently reported in fetuses before 24 weeks [17,22,53,54]; therefore, vermis hypoplasia and elevated roof of the fourth ventricle were used for the prenatal diagnosis of JS.…”

Section: Study Subjectsmentioning

confidence: 99%

Joubert syndrome: brain and spinal cord malformations in genotyped cases and implications for neurodevelopmental functions of primary cilia

et al. 2012

View full text Add to dashboard Cite

Joubert syndrome (JS) is an autosomal recessive ciliopathy characterized by hypotonia, ataxia, abnormal eye movements, and intellectual disability. The brain is malformed, with severe vermian hypoplasia, fourth ventriculomegaly, and "molar tooth" appearance of the cerebral and superior cerebellar peduncles visible as consistent features on neuroimaging. Neuropathological studies, though few, suggest that several other brain and spinal cord structures, such as the dorsal cervicomedullary junction, may also be affected in at least some patients. Genetically, JS is heterogeneous, with mutations in 13 genes accounting for approximately 50% of patients. Here, we compare neuropathologic findings in five subjects with JS, including four with defined mutations in OFD1 (2 siblings), RPGRIP1L, or TCTN2. Characteristic findings in all JS genotypes included vermian hypoplasia, fragmented dentate and spinal trigeminal nuclei, hypoplastic pontine and inferior olivary nuclei, and nondecussation of corticospinal tracts. Other common findings, seen in multiple genotypes but not all subjects, were dorsal cervicomedullary heterotopia, nondecussation of superior cerebellar peduncles, enlarged arcuate nuclei, hypoplastic reticular formation, hypoplastic medial lemnisci, and dorsal spinal cord disorganization. Thus, while JS exhibits significant neuropathologic as well as genetic heterogeneity, no genotype-phenotype correlations are apparent as yet. Our findings suggest that primary cilia are important for neural patterning, progenitor proliferation, cell migration, and axon guidance in the developing human brain and spinal cord.

show abstract

Section: Study Subjectsmentioning

confidence: 99%

Joubert syndrome: brain and spinal cord malformations in genotyped cases and implications for neurodevelopmental functions of primary cilia

et al. 2012

View full text Add to dashboard Cite

show abstract

“…[18][19][20] No sensitivity data are available in this regard: the 2 relatively largest series (of 3 and 7 cases of molar tooth malformation), with a total of 4 cases with early diagnoses (before 25 weeks' GA) by MR imaging or US, were affected by a selection bias; because these cases were within a possible recurrence exclusion prospective protocol, the scanning technique and radiologist were likely to be particularly focused on highlighting minimal heralding signs. 21,22 At an early GA, besides the presence of a smaller vermis and abnormal fourth ventricle shape on midsagittal sections, the definitive evidence of a molar tooth footprint in the midbrain-superior cerebellar peduncle complex may often be visible in only 1 single axial section, unless more axial acquisitions are acquired with different tilting though the brain stem under the guidance of an a priori hypothesis. In our fetus at 22 weeks' GA, we reported a smaller vermis according to the reference data, 23 with an anteroposterior diameter of 4 mm and a superior-inferior diameter of 7 mm, but we did not detect the molar tooth footprint in midbrainsuperior cerebellar peduncles, which was visible on only 1 section (On-line Fig 1B and -C).…”

Section: Posterior Fossa Anomaliesmentioning

confidence: 99%

Diagnostic Value of Prenatal MR Imaging in the Detection of Brain Malformations in Fetuses before the 26th Week of Gestational Age

Conte

Parazzini²,

Falanga

et al. 2015

American Journal of Neuroradiology

View full text Add to dashboard Cite

show abstract

“…Molar tooth sign associated with JSRD has previously been demonstrated by fetal MRI in three cases. Saleem and associates were able to identify the molar tooth sign as early as 22 weeks of gestation (14). MTS was identified at 27 weeks of gestation in two other cases (13,15).…”

Section: Discussionmentioning

confidence: 93%

Joubert syndrome and related disorders, prenatal diagnosis with ultrasound and magnetic resonance imaging

İskender

Tarım

Alkan

2011

J Turkish German Gynecol Assoc

View full text Add to dashboard Cite

Joubert syndrome (JBTS) is an autosomal recessive disorder characterized by intellectual disability, hypotonia, ataxia, tachypnea/apnea, and abnormal eye movements. A pathognomonic midbrain-hindbrain malformation seen on cranial magnetic resonance imaging (MRI), which consists of hypoplasia of the midline cerebellar vermis that resembles the cross-section through a molar tooth, has been described previously.The molar tooth sign is defined by a peculiar appearance resembling a molar tooth secondary to an abnormally deep interpeduncular fossa and enlarged superior cerebellar peduncles on axial images at the pontomesencephalic level. The term Joubert Syndrome and Related Disorders (JSRD) has recently been adopted to describe all disorders presenting the "molar tooth sign" (MTS) on brain imaging. JSRD is characterized by lack of decussation of the superior cerebellar peduncles, central pontine tracts and corticospinal tracts suggesting defective axon guidance. Prenatal sonographic findings in fetuses with JSRD are relatively nonspecific and include increased nuchal translucency, enlarged cisterna magna, cerebellar vermian agenesis, occipital encephalocele, ventriculomegaly and polydactyly. We report a case of JSRD detected prenatally at 23 weeks of gestation. The fetus in the present case had a normal karyotype. Sonographic features of the fetus included polydactyly, partial vermian hypoplasia, dilated 4 th ventricle and mild ventriculomegaly which were also confirmed by prenatal MRI. MTS was demonstrated in a postnatal MRI after pregnancy termination. (J Turkish-German Gynecol Assoc 2012; 13: 135-8)

show abstract

Role of MR Imaging in Prenatal Diagnosis of Pregnancies at Risk for Joubert Syndrome and Related Cerebellar Disorders

Abstract: BACKGROUND AND PURPOSE: JSRD are rare autosomal recessive brain malformations. We hypothesized that MR imaging can assess fetuses at risk for JSRD and might influence their diagnoses.

Cited by 47 publications

References 39 publications

Joubert syndrome: brain and spinal cord malformations in genotyped cases and implications for neurodevelopmental functions of primary cilia

Joubert syndrome: brain and spinal cord malformations in genotyped cases and implications for neurodevelopmental functions of primary cilia

Diagnostic Value of Prenatal MR Imaging in the Detection of Brain Malformations in Fetuses before the 26th Week of Gestational Age

Joubert syndrome and related disorders, prenatal diagnosis with ultrasound and magnetic resonance imaging

Contact Info

Product

Resources

About