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At least 19 recordsLinked to original sources
PubMed1997

Clinical and molecular analysis in Joubert syndrome.

Joubert syndrome is an autosomal recessive disorder comprising cerebellar hypoplasia, hypotonia, developmental delay, abnormal respiratory patterns, and abnormal eye movements. The biochemical basis of the Joubert syndrome is unknown. We ascertained a cohort of 50 patients with the Joubert syndrome to evaluate the presence of associated malformations, and to initiate studies leading to the identification of the Joubert syndrome gene. Only 8% of patients had polydactyly, 4% colobomas, 2% renal cysts, and 2% had soft tissue tumors of the tongue. In addition, we evaluated the WNT1 gene as a candidate gene for the Joubert syndrome based on its expression in the developing cerebellum and an associated mutation in the swaying mouse. We searched for mutations in WNT1 in a series of Joubert syndrome patients and no mutations were detected. Our analysis suggests that mutations in WNT1 do not cause the Joubert syndrome.

Abnormalities, Multiple↗
PubMedDate not supplied

The role of 99mTc DMSA renal scintigraphy in Joubert syndrome.

Joubert syndrome is a severe autosomal recessive disorder, which is characterized by hypotonia, impaired psychomotor development, retinal dystrophy with abnormal ocular movements and cerebellar vermis agenesis with dilatation of the fourth ventricle. Joubert syndrome type B is a developmental disorder of the nephronophtisis complex with multiple organ involvement. Although this syndrome is rare, since first described by Joubert et al in 1969, there have been several cases about the components and the chromosomal abnormalities related with it. Here we report 2 patients with Joubert syndrome in whom renal involvement was demonstrated by ultrasonography as renal cystic disorders which represented nephronophtisis. For each patient we performed renal cortical scintigraphy with 99mTc-DMSA ( 99mtechnetium-dimercaptosuccinic acid) which showed bilaterally decreased radiopharmaceutical uptake in kidneys due to tubulointerstitial nephropathy. Scintigraphy may have a great value in the diagnosis and evaluation of the presence and severity of renal involvement in Joubert syndrome since it can evaluate kidney parenchyma and functioning renal tissue.

Child↗
PubMed2004

Abnormal cerebellar development and axonal decussation due to mutations in AHI1 in Joubert syndrome.

Joubert syndrome is a congenital brain malformation of the cerebellar vermis and brainstem with abnormalities of axonal decussation (crossing in the brain) affecting the corticospinal tract and superior cerebellar peduncles. Individuals with Joubert syndrome have motor and behavioral abnormalities, including an inability to walk due to severe clumsiness and 'mirror' movements, and cognitive and behavioral disturbances. Here we identified a locus associated with Joubert syndrome, JBTS3, on chromosome 6q23.2-q23.3 and found three deleterious mutations in AHI1, the first gene to be associated with Joubert syndrome. AHI1 is most highly expressed in brain, particularly in neurons that give rise to the crossing axons of the corticospinal tract and superior cerebellar peduncles. Comparative genetic analysis of AHI1 indicates that it has undergone positive evolutionary selection along the human lineage. Therefore, changes in AHI1 may have been important in the evolution of human-specific motor behaviors.

Abnormalities, Multiple↗
PubMed2005

Mitochondrial dysfunction in a patient with Joubert syndrome.

Joubert syndrome is a genetically heterogeneous disorder. The diagnostic criteria include episodic hyperventilation, abnormal eye movements, psychomotor retardation, hypotonia, ataxia, and the characteristic neuro-imaging findings (molar-tooth sign). Many of these clinical features have been observed in new-borns with mitochondrial disorders as well. Congenital brain malformations, including cerebellar hypoplasia, have been described in pyruvate dehydrogenase deficiency. Malformations of the vermis and the cerebellar peduncles, with the lack of axonal decussations, however, are characteristic for Joubert syndrome but unique in patients with mitochondrial disorders. Here, we describe a child with Joubert syndrome presenting with primary lactic acidemia, decreased pyruvate oxidation rates, decreased ATP production, and a mildly decreased pyruvate dehydrogenase complex activity measured in a fresh muscle biopsy. Sequence analysis of the PDHc E1 alpha gene and the PDHX genes revealed no mutations. The patient received continuous feeding through a feeding tube for two years and showed a significant clinical improvement with a complete resolution of the chronic lactic acidemia. A second muscle biopsy revealed significantly decreased pyruvate oxidation rates and ATP production, but a normal pyruvate dehydrogenase complex activity. We suggest that the described mitochondrial dysfunction in our patient is secondary to an underlying mutation leading to Joubert syndrome.

Abnormalities, Multiple↗
PubMed2005

Burkitt lymphoma in a child with Joubert syndrome.

Joubert syndrome is a rare disorder, characterized by hypoplasia, or aplasia of the cerebellar vermis, hypotonia, ataxia, and psychomotor retardation. The molecular basis underlying the disease is still unknown. There are various syndromes, which are associated with malignancies. Previously known associations between Joubert syndrome and tumors, are benign soft tissue tumors of the tongue and laryngeal lymphangioma. This report describes a 17-year-old boy known with Joubert syndrome, who was diagnosed with Burkitt lymphoma. The boy received chemotherapy, which successfully induced complete remission.

Abnormalities, Multiple↗
PubMedDate not supplied

Brain stem and cerebellar findings in Joubert syndrome.

Joubert syndrome is often missed clinically and radiologically if not enough attention is paid to its subtle and variable clinical presentation and the imaging findings in the posterior fossa. The purpose of this paper is to illustrate the brain stem and cerebellar imaging findings in Joubert syndrome. Awareness of the clinical and neuroimaging findings in Joubert syndrome and maintenance of a high index of suspicion are essential to correctly diagnose this rare congenital malformation.

Abnormalities, Multiple↗
PubMed1989

Joubert syndrome.

Joubert syndrome is an autosomal recessive condition in which there is a variable combination of central nervous system defects with a distinctive congenital retinal dystrophy, ocular motor abnormalities, and respiratory abnormalities in early infancy. The retinal dystrophy has been previously classified as a variant of Leber's congenital amaurosis. We report electrophysiologic and eye movement findings in a series of seven consecutive children with Joubert syndrome. Unlike patients with Leber's congenital amaurosis, all but one of these children had preserved flash and pattern-reversal visual evoked potentials. Six of the seven children had abnormalities of smooth pursuit, optokinetic nystagmus, and saccades. Six of the children had nystagmus: three had a pendular torsional nystagmus and three had a form of see-saw nystagmus. An alternating hyperdeviation was present in five of the patients, two of whom also had a tonic deviation of their eyes laterally. All seven patients had cerebellar vermis hypoplasia on a magnetic resonance imaging scan. Developmentally delayed children with an absent or highly attenuated electroretinogram should be investigated for Joubert syndrome.

Blindness↗
PubMed1995

[Joubert syndrome].

Joubert syndrome was first described in 1969 and 100 cases have been published so far. It includes: partial or complete agenesis of the vermis, episodic hyperpnea, ataxia, a disorder of ocular movement and mental retardation. It is autosomal recessive and there are descriptions of families with involvement of multiple children, both boys and girls. Since dysmorphic signs are not prominent in this syndrome, diagnosis is often delayed. To the best of our knowledge, Joubert syndrome has not been previously described in Israel. We present a family with 3 siblings with this syndrome. Increased awareness will lead to earlier diagnosis, proper developmental treatment, and accurate genetic counseling.

Abnormalities, Multiple↗
PubMed2003

Recognition of the clinical signs and symptoms of Joubert syndrome.

Joubert Syndrome is a rare, autosomal recessive disorder that affects the cerebellum and brain stem. It presents with a distinct respiratory pattern and profound tachypnea in the newborn period. This article provides an overview of the condition and discusses the embryologic origins of this syndrome. A focused history and systematic physical assessment provide a step-by-step guide to enhance the early recognition of clinical signs and symptoms of this disorder. A series of clinical photographs and a brief case report offer insight into the classic presentation of this uncommon disorder. The diagnosis of Joubert syndrome is confirmed with magnetic resonance imaging, which reveals a classic neuroradiologic finding, characterized as the molar tooth sign. A discussion of the range of developmental outcomes and complex multispecialty care and intensive support that these infants and their families require is also provided.

Abnormalities, Multiple↗
PubMed1996

A case of cranial meningocele associated with Joubert syndrome.

Joubert syndrome was first reported in 1969 as a rare, recessive autosomal syndrome associated with neuropathological abnormalities of the cerebellum and brain stem, partial or complete aplasia of the cerebellar vermis, and presenting with episodic hyperpnea and apnea, oculomotor abnormalities, and psychomotor retardation. Having experienced one case of this syndrome with associated cranial meningocele, we report the clinical course, MRI features, and surgical findings, and discuss the relevant literature.

Brain Stem↗
PubMed2005

Identification of the first AHI1 gene mutations in nephronophthisis-associated Joubert syndrome.

Joubert syndrome (JBTS) is an autosomal recessive multisystem disease characterized by cerebellar vermis aplasia, mental retardation, muscular hypotonia, an irregular breathing pattern in the neonatal period and abnormal eye movements. Some individuals have progressive renal failure characterized by nephronophthisis (NPHP) and/or retinal dystrophy. Homozygous deletions of NPHP1 on chromosome 2q13 have been identified in individuals with NPHP-associated JBTS. Recently, mutations in AHI1 on chromosome 6q23.3 were found in JBTS patients without NPHP. Here, by direct sequencing, we identify novel truncating mutations within AHI1 in affected patients from two families. One patient had the association of JBTS and NPHP with chronic renal failure. This is the first report of AHI1 mutations causing JBTS associated with NPHP, confirming the clinical and genetic heterogeneity of NPHP.

Adaptor Proteins, Signal Transducing↗
PubMed2004

The NPHP1 gene deletion associated with juvenile nephronophthisis is present in a subset of individuals with Joubert syndrome.

Joubert syndrome (JS) is an autosomal recessive multisystem disease characterized by cerebellar vermis hypoplasia with prominent superior cerebellar peduncles (the "molar tooth sign" [MTS] on axial magnetic resonance imaging), mental retardation, hypotonia, irregular breathing pattern, and eye-movement abnormalities. Some individuals with JS have retinal dystrophy and/or progressive renal failure characterized by nephronophthisis (NPHP). Thus far, no mutations in the known NPHP genes, particularly the homozygous deletion of NPHP1 at 2q13, have been identified in subjects with JS. A cohort of 25 subjects with JS and either renal and/or retinal complications and 2 subjects with only juvenile NPHP were screened for mutations in the NPHP1 gene by standard methods. Two siblings affected with a mild form of JS were found to have a homozygous deletion of the NPHP1 gene identical, by mapping, to that in subjects with NPHP alone. A control subject with NPHP and with a homozygous NPHP1 deletion was also identified, retrospectively, as having a mild MTS and borderline intelligence. The NPHP1 deletion represents the first molecular defect associated with JS in a subset of mildly affected subjects. Cerebellar malformations consistent with the MTS may be relatively common in patients with juvenile NPHP without classic symptoms of JS.

Adaptor Proteins, Signal Transducing↗
PubMed2006

Mutations in CEP290, which encodes a centrosomal protein, cause pleiotropic forms of Joubert syndrome.

Joubert syndrome-related disorders (JSRD) are a group of syndromes sharing the neuroradiological features of cerebellar vermis hypoplasia and a peculiar brainstem malformation known as the 'molar tooth sign'. We identified mutations in the CEP290 gene in five families with variable neurological, retinal and renal manifestations. CEP290 expression was detected mostly in proliferating cerebellar granule neuron populations and showed centrosome and ciliary localization, linking JSRDs to other human ciliopathies.

Animals↗
PubMed2000

Patient with large 17p11.2 deletion presenting with Smith-Magenis syndrome and Joubert syndrome phenotype.

We report on a 22-year-old woman carrying a del(17)(p11.2p12) and presenting with the clinical manifestations of both Smith-Magenis syndrome (SMS) and Joubert syndrome (JS). Her facial anomalies, brachydactyly, severe mental retardation, and self-injuring behavior could be attributed to SMS, whereas the cerebellar vermis hypoplasia, hypotonia, ataxic gait, developmental delay, and abnormal respiratory pattern were suggestive of JS. By fluorescent in situ hybridization analyses with Yeast Artificial Chromosomes (YAC) mapping to the 17p11.2 region, as well as locus-specific probes generated through a novel procedure, we could establish that the deletion encompasses a 4-Mb interval with centromeric and telomeric breakpoints at loci D17S793 and D17S953, the latter close to the locus Charcot Marie Tooth 1A (CMT1A)-REP. The deletion differs from that commonly found in SMS in its telomeric boundary, which is more distal than usually observed. The presence of JS phenotype in our patient and the detection of an unusual SMS deletion might suggest the presence of a JS gene in close proximity to the SMS locus.

Abnormalities, Multiple↗
PubMed1994

[Joubert syndrome].

Joubert's syndrome is clinically characterized by attacks of tachypnea alternating with respiratory pauses, abnormal ocular movements, psychomotor retardation, and ataxia. Anatomic anomalies include cerebellar vermis agenesis with dilatation of the fourth ventricle. It is an autosomal recessive disorder; onset is in the neonatal period and prognosis is severe.

Cerebellar Ataxia↗
PubMedDate not supplied

[Joubert syndrome combined with unilateral facial paralysis: a rare variant of Joubert syndrome].

We report the case of a mature newborn infant, which aroused attention 8 hours after birth due to an unexplainable paroxysmal tachypnea together with subsequently prolonged apnea. The combination of tachypnea, athetoid movement patterns, apraxia of the tongue, nystagmus and dysplasia of the cerebellum with dilation of the 4th ventricle, led to the diagnosis of Joubert-Syndrome. The child also showed a variation of a connatal unilateral facial nerve palsy, which has not previously been described in connection with a Joubert-Syndrome.

Apnea↗