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Individual conditions grouped according to the international nosology and classification of genetic skeletal disorders*
Published in Christine M Hall, Amaka C Offiah, Francesca Forzano, Mario Lituania, Michelle Fink, Deborah Krakow, Fetal and Perinatal Skeletal Dysplasias, 2012
Christine M Hall, Amaka C Offiah, Francesca Forzano, Mario Lituania, Michelle Fink, Deborah Krakow
Joubert syndrome is a heterogeneous group of disorders which can present with retinal dystrophy and renal anomalies, but is characterised more specifically by hypoplasia of the cerebellar vermis, the characteristic neuroradiological ‘molar tooth sign’, abnormal neurological development and rarely occipital myelomeningocoele.
Meckel Gruber and Joubert Syndrome Diagnosed Prenatally: Allelism between the Two Ciliopathies, Complexities of Mutation Types and Digenic Inheritance
Published in Fetal and Pediatric Pathology, 2022
Somya Srivastava, Rani Manisha, Aradhana Dwivedi, Harshita Agarwal, Deepti Saxena, Vinita Agrawal, Kausik Mandal
Joubert syndrome was initially characterized by ataxia, intellectual disability, abnormal eye movements, agenesis of cerebellar vermis and occasional hyperpnea [14]. Agenesis of cerebellar vermis along with deep interpeduncular fossa gives rise to the “molar tooth sign” on MRI brain. This characteristic sign was delineated in 1997 [15]; several years after the first description of the syndrome in 1969. The molar tooth sign was identified in several disorders and the term ‘Joubert syndrome related disorders’ was coined to encompass all defects with molar tooth sign. This syndrome was further subdivided into six clinical types depending upon the presence or absence of additional features: pure Joubert syndrome, JS with ocular defect, JS with renal defect, JS with oculorenal defect, JS with hepatic defect, and JS with orofaciodigital defect highlighting the clinical heterogeneity of this syndrome [16]. Presently, 36 causative genes have been identified [3].
Challenges and resources in adult life with Joubert syndrome: issues from an international classification of functioning (ICF) perspective
Published in Disability and Rehabilitation, 2022
Romina Romaniello, Chiara Gagliardi, Patrizia Desalvo, Livio Provenzi, Roberta Battini, Enrico Bertini, Maria Teresa Bonati, Marilena Briguglio, Stefano D’Arrigo, Maria Teresa Dotti, Lucio Giordano, Claudio Macaluso, Isabella Moroni, Sara Nuovo, Margherita Santucci, Sabrina Signorini, Franco Stanzial, Enza Maria Valente, Renato Borgatti
Joubert Syndrome (JS) is a rare inherited congenital cerebellar ataxia, with a prevalence of 0.5 per 100.000 in the overall population and 1.8 per 100.000 in the age range 0–19 years [1]. A peculiar cerebellar and brainstem malformation, named “the molar tooth sign” (MTS), represents the hallmark sign of the syndrome [2]. It is characterized by a deepened interpeduncular fossa with narrow isthmus and upper pons, thickened, elongated and misoriented superior cerebellar peduncles, and vermian hypoplasia/dysplasia, overall giving the appearance of a tooth on axial brain magnetic resonance imaging (MRI) [3]. JS is part of an expanding group of disorders called ciliopathies that are caused by the dysfunction of the primary cilium, an ubiquitous subcellular organelle which plays a key role in many tissues and during embryonic development [4]. JS typically manifests in neonatal age with hypotonia later evolving into ataxia, but the clinical phenotype of this syndrome is widely heterogeneous, and variably features retinal, renal, hepatic, skeletal and orofacial defects [5]. Although most affected children present intellectual disability and delay in the acquisition of psychomotor milestones, along the development the cognitive profile may present a wide spectrum, ranging from normal cognitive competences to severe intellectual disability [6–9]. Despite the latter being less frequent in JS than in other cerebellar malformations, specific impairments (e.g., language, working memory) impact on the cognitive profile and therefore on the everyday life and personal wellbeing of most JS individuals [10,11].
Investigation of CEP290 genotype-phenotype correlations in a patient with retinitis pigmentosa, infertility, end-stage renal disease, and a novel mutation
Published in Ophthalmic Genetics, 2020
Madeline Williamson, Elias Traboulsi, Meghan DeBenedictis
Leber congenital amaurosis (LCA; MIM $204000) describes a type of retinal dystrophy that manifests at a very early age as a result of retinal pigment epithelium and rod and cone photoreceptor cell death. It is characterized by congenital nystagmus, photophobia, severe visual impairment, and severely reduced or extinguished responses on electroretinogram. Senior-Loken syndrome includes the LCA phenotype of the retina along with renal disease most commonly presenting as juvenile nephronophthisis that can progress to kidney failure that may eventually require transplantation. Joubert syndrome (JBTS) is an autosomal recessive disorder characterized by a variable combination of central nervous system defects with a distinctive congenital retinal dystrophy, ocular motor abnormalities, respiratory abnormalities in early infancy, and a characteristic molar tooth sign on brain MRI (2,3). Patients may also have ocular coloboma, hepatic fibrosis, and congenital cystic kidney disease (4,5). Meckel-Gruber syndrome is the most severe CEP290-related disease and is nearly always fatal by the neonatal period. Patients have intrauterine growth retardation with systemic abnormalities including cystic kidneys, polydactyly, encephalocele, and liver fibrosis (6).