Search

Background: Joubert syndrome (JS) is an autosomal recessive disorder with a distinctive mid-hindbrain malformation known as the "molar tooth sign" which involves the breathing control center and its connections with other structures. Literature has reported significant respiratory abnormalities which included hyperpnea interspersed with apneic episodes during wakefulness. Larger-scale studies looking at polysomnographic findings or subjective reports of sleep problems in this population have not yet been published. Objectives: The primary objectives were (1) compare a large group of children with JS and their unaffected siblings for caregiver-reported sleep difficulties. Secondary objectives were (1) present new polysomnography (PSG) data on our JS cohort; (2) review sleep disordered breathing (SDB) in other rare congenital hindbrain anatomic abnormalities. Design: We conducted a cross-sectional study on a cohort of 109 families affected by JS. Methods: Pediatric Sleep Questionnaire (PSQ) and the Children's Sleep Habits Questionnaire (CSHQ) along with general medical health information focused on respiratory and sleep problems were mailed to all patients and families. Caregivers were asked to complete the survey for both children with JS and unaffected siblings, if any. Baseline diagnostic PSG was retrospectively reviewed for those with available studies, and the sleep parameters were compared to a referent cohort. Results: Study participants with JS were older than their unaffected siblings (p = 0.02). Genetic mutations were available for 41 out of 118 individuals, with the most common mutation being MKS3 (31.4%). Patients with JS had higher scores in the PSQ compared to their unaffected siblings (p < 0.001). PSG data showed severe SDB with apnea-hypopnea index (AHI) of 23 ± 15 events/h in patients with JS. Events were primarily obstructive (obstructive AHI 18 ± 15 events/h vs central AHI 4 ± 4 events/h). Abnormal sleep architecture with increased arousal indices, decreased efficiency, and more time awake and in light sleep or wakefulness when compared to the referent data. Conclusion: SDB is common and severe in patients with JS, and the significantly greater obstructive component reported in this cohort makes it necessary to perform complete PSG studies to address or prevent clinical manifestations in this at-risk population. PSQ could represent a viable method to screen for SDB in JS. [ABSTRACT FROM AUTHOR]

The primary cilium is a hair-like organelle that hosts molecular machinery for various developmental and homeostatic signaling pathways. Its alteration can cause rare ciliopathies such as the Bardet-Biedl and Joubert syndromes, but is also linked to Alzheimer's disease, clinical depression, and autism spectrum disorder. These afflictions are caused by disturbances in a wide variety of genes but a common phenotype amongst them is cognitive impairment. While cilia-mediated neural function has been widely examined in early neurodevelopment, their function in the adult brain is not well understood. To help elucidate the role of cilia in neural activity, we temporally induced the ablation of IFT88, a gene encoding the intraflagellar transport 88 protein which is neccessary for ciliogenesis, in adult mice before performing memory-related behavioral assays and electroencephalogram/electromyogram (EEG/EMG) recordings. Inducible IFT88 KO mice exhibited severe learning deficits in trace fear conditioning and Morris water maze tests. They had strongly affected brainwave activity both under isoflurane induced anesthesia and during normal activity. And additionally, inducible IFT88 KO mice had altered sleep architecture and attenuated phase-amplitude coupling, a process that underlies learning and memory formation. These results highlight the growing significance of primary cilia for healthy neural function in the adult brain. [ABSTRACT FROM AUTHOR]

ABSTRACT Renal ciliopathies are a genetically and phenotypically heterogeneous group of diseases characterized by cystic and dysplastic kidneys. The aim of this study was to investigate the correlation between genetic changes that cause renal ciliopathies and phenotypic outcomes. The study group consisted of 137 patients diagnosed with renal ciliopathy disease. One hundred nineteen patients had ADPKD phenotype, 7 patients had ARPKD phenotype, 4 patients had nephronophthisis, 1 patient had Senior‐Loken syndrome, 4 patients had Bardet‐Biedl syndrome, 1 patient had Joubert syndrome and 1 patient had Meckel Gruber syndrome phenotype. Among patients with autosomal dominant polycystic kidney disease, patients with the PKD1 gene mutation had higher creatinine levels (p value: 0.020) and no arachnoid cysts were revealed in the PKD2 group (p value: 0.014). When the domains were compared, the finding of arachnoid cyst in patients with mutations in the transmembrane domain was statistically significant (p value: 0.021). Homozygous likely pathogenic variant in the TCTN1 gene was reported in a fetus who had findings of Meckel‐Gruber syndrome; microphthalmia and cardiac hypoplasia were reported as novel findings. As a conclusion, we identified variant spectrum of renal ciliopathies in Turkish cohort and revealed the association between the transmembrane domain and arachnoid cyst. [ABSTRACT FROM AUTHOR]

Background: Prenatal whole exome sequencing (WES) is becoming an increasingly used diagnostic tool for fetuses with structural anomalies. However, the identification of variants of uncertain significance (VUS) in clinically relevant genes can significantly complicate prenatal diagnosis and genetic counseling. Case presentation: A fetus conceived through in vitro fertilization at the third attempt presented with polydactyly and molar tooth sign at 24 + 6 weeks of gestation. Trio-based WES was performed on both parents and the affected fetus, revealing a pair of compound heterozygous CPLANE1 variants (c.4646 A > T/p.Glu1549Val and c.1233 C > A/p.Tyr411*) potentially associated with Joubert syndrome. According to the ACMG guidelines, one of the biallelic variants was classified as VUS, and the other as pathogenic. However, these variants had no allele frequencies in the general population. The p.Tyr411* variant was classified as deleterious, while the p.Glu1549Val variant was located in highly conserved residues, was predicted to be damaging by in silico tools, and altered hydrogen bonding. Furthermore, CPLANE1 expression was highest in the brain during the embryonic and fetal stages. These findings provide additional support for the association between CPLANE1 variants in this fetus and Joubert syndrome. Thus, the most likely diagnosis was Joubert syndrome, and after careful consideration, the couple decided to terminate the pregnancy. Conclusion: The expression patterns of CPLANE1 and the molecular effects of the variants may provide further evidence supporting the potential for prenatal diagnosis of Joubert syndrome in the case of biallelic VUS and pathogenic variant. This study suggests that molecular insights may play a role in interpreting VUS in clinically relevant prenatal genes for prenatal diagnosis. [ABSTRACT FROM AUTHOR]

Background: Leber congenital amaurosis (LCA) is a congenital onset severe form of inherited retinal dystrophy (IRD) and a common cause of pediatric blindness. Disease-causing variants in at least 14 genes are reported to predispose LCA phenotype. LCA is inherited as an autosomal recessive disease. It can be an isolated eye disorder or as part of a syndrome, such as Senior Loken or Joubert syndrome. Sequencing studies from consanguineous populations have proven useful for novel variants identification; thus, the present study aimed to explore the genetic heterogeneity of 15 consanguineous Pakistani families, each segregating a severe IRD phenotype using targeted next generation sequencing. Methods: This study enrolled 15 consanguineous families, each with multiple affected cases of retinal dystrophy phenotype. DNA was extracted from blood samples. Targeted panel sequencing of 344 known genes for IRDs was performed, followed by Sanger sequencing for segregation analysis. Results: Data analysis revealed a total of eight reported (c.316C>T and c.506G>A in RDH12; c.864dup and c.1012C>T in SPATA7, as well as c.1459T>C, c.1062_1068del, c.1495+1G>A, c.998G>A in the CRB1, LCA5, TULP1, and IFT140 genes, respectively) and four novel homozygous (c.720+1G>T in LCA5, c.196G>C in LRAT, c.620_625del in PRPH2, and c.3411_3414del in CRB1) variants segregating with disease phenotype in each respective family. Furthermore, a novel heterozygous variant of CRB1 gene, i.e., c.1935delC in compound heterozygous condition was found segregating with disease phenotype in one large family with multiple consanguinity loops. Conclusion: Comprehensive molecular diagnosis of 15 consanguineous Pakistani families led to the identification of a total of 5 novel variants contributing to genetic heterogeneity of LCA-associated genes and helped to provide genetic counseling to the affected families. [ABSTRACT FROM AUTHOR]

The article discusses early Joubert syndrome and related disorders (JSRD) and the development of the molar tooth sign (MTS) in the brain. Through a case series using transvaginal neurosonography, the study identified genetic variants associated with JSRD and highlighted the importance of early prenatal diagnosis. The research sheds light on the mechanism of the open isthmus, represented by the lambda sign, and its role in the eventual development of the MTS. Understanding these early markers may enable prenatal diagnosis of JSRD in the first trimester, before the formation of the superior cerebellar peduncles, which are crucial for the MTS. [Extracted from the article]

Background & Objective: Neurological disorders significantly impact patients' mental, personality, and movement functions, with a rising prevalence globally, especially in low-income and middleincome countries. This study aims to evaluate gene mutations in pediatric neurological disorders patients to contribute to our understanding of these disorders' genetic basis. Methods: In the current survey, all patients with maternal signs of neurological disorders who were referred to the neurology department during 2023 to 2024 were evaluated. DNA samples from patients were enriched using the Agilent SureSelect Human All Exon Kit V6, and subsequent sequencing took place on an Illumina HiSeq 4000 platform based on the manufacturer's procedures. Results: In the current cross-sectional study, 13 patients with maternal neurological disorders including 6 males (46%) and 7 females (54%) were evaluated. Our results identified inherited neurological disorders, including Joubert syndrome, Pelizaeus-Merzbacher disease, and giant axonal neuropathy-1. Our data identified a novel missense mutation in exon 8 of PLP1 gene (NM_001128834.3: c.772A>C; p.Met258Leu) with X-linked recessive inheritance in a patient with Pelizaeus-Merzbacher disease. Gene variants, including CSPP1 frameshift mutation in exon 20 (NM_001382391.1: c.2259_2260delAA; p.Glu755GlyfsTer30), and autosomal recessive homozygous TMEM67 mutation in exon 8 (NM_153704.6: c.725A>G; p.Asn242Ser) were detected in patients with Joubert syndrome. Finally, in a patient with giant axonal neuropathy-1, a homozygous GAN mutation (NM_022041.4: c.1177T>C; p.Cys393Arg) was detected. Conclusion: Our findings can be useful in understanding the pathophysiology of neurological disorders. Also, this study indicated the importance of genetic analysis in utilizing the treatment strategy in patients with neurological disorders. [ABSTRACT FROM AUTHOR]

Liang Chen,1,&ast; Mei-Fang Zhao,2,&ast; Hui-Wen Deng,1 Min Liao,1 Liang-Liang Fan,2 Qi-Bao Zhong,3 Jun Wang,1 Ke Li,1 Zheng-Hui Wu,4,&ast; Jian-Yin Yin1 1Department of Anesthesiology, Hunan Provincial Maternal and Child Health Care Hospital, Changsha, 410008, People’s Republic of China; 2Department of Cell Biology, School of Life Sciences, Central South University, Changsha, 410013, People’s Republic of China; 3Department of Facial Features, Hunan Provincial Maternal and Child Health Care Hospital, Changsha, 410008, People’s Republic of China; 4Department of Child Rehabilitation, Hunan Provincial Maternal and Child Health Care Hospital, Changsha, 410008, People’s Republic of China&ast;These authors contributed equally to this workCorrespondence: Jian-Yin Yin, Department of Anesthesiology, Hunan Provincial Maternal and Child Health Care Hospital. No. 53, Xiangchun Road, Kaifu District, Changsha, 410008, People’s Republic of China, Email 357773796@qq.comAbstract: Joubert syndrome (JS) is an infrequent congenital neurodevelopmental ciliopathy, typically identified in children around the average age of 33 months. This disorder is characterized by developmental delay, cognitive impairment, and infantile hypotonia that may evolve into ataxia. Mutations in OFD1 results in Joubert syndrome with a variety of phenotypes. Here, we identified a child who presented with Joubert syndrome exhibiting orofaciodigital spectrum anomalies, polydactyly, and retinitis pigmentosa. Whole exome sequencing and Sanger sequencing revealed a splicing mutation (NM_003611.2, c.2387+1G>A) in the OFD1 gene of the patient and his mother. mRNA sequencing further confirmed this mutation. However, since the patient is homozygous and the mother is heterozygous, only the patient has the phenotype and the mother is normal. This mutation can lead to the loss of sixth coiled-coil domains of OFD1 protein, which further disrupt the ciliary signaling pathway and Hedgehog signaling pathway. This study presents a new case of JS and expands the mutant spectrum of OFD1, but also enhances our understanding of the mechanism by which OFD1 is associated with ciliosis.Keywords: Joubert syndrome, OFD1, splicing mutation, ciliosis

Joubert syndrome is a rare autosomal recessive disorder characterized by the presence of the molar tooth sign on imaging. We report the case of a 5-year-old girl diagnosed with Joubert syndrome during the investigation of chronic vomiting. The patient presented with neuropsychomotor delay, a history of neonatal respiratory disorders, and hydrocephalus treated with a ventriculoperitoneal shunt. Brain magnetic resonance imaging revealed a deepened interpeduncular fossa, thickening and horizontalization of the upper cerebellar peduncles, and vermian hypoplasia, resulting in the characteristic ''molar tooth'' appearance. The neuropsychomotor delay was attributed to Joubert syndrome, while the chronic vomiting was linked to hyperdrainage. This case underscores the potential for clinical signs of Joubert syndrome to confuse clinicians and highlights the importance of recognizing the pathognomonic molar tooth sign in imaging, which all radiologists should be familiar with.

Joubert Syndrome, manifests in a spectrum of neurological symptoms. This case describes a 7-year-old girl with perinatal complications, and subsequent neurodevelopmental challenges. An MRI confirmed the diagnosis of Joubert syndrome, with the distinctive “molar tooth sign” being a key imaging characteristic. Approximately 25% of cases exhibit nephronophthisis, impacting kidney function, further complicating the clinical picture. Diagnosis relies on imaging and management necessitates a multidisciplinary approach, addressing symptoms and complications, with prognosis linked to the presence of organic disease. The case emphasizes the significance of a multidisciplinary strategy, including genetic counseling, and underscores the diverse manifestations of this syndrome. Prenatal identification through ultrasound and MRI plays a crucial role in diagnosing and treating this rare condition.

Joubert syndrome (JS) is a rare autosomal recessive disorder with brain stem and cerebellar malformations. Early diagnosis through Magnetic Resonance Imaging (MRI) and ultrasonography (US) is crucial for managing this condition. This report presents a JS case diagnosed at 24 weeks of pregnancy. A 25-year-old gravida 2, para 1 woman was referred at 24 weeks’ gestation for suspected posterior fossa abnormalities. Ultrasound revealed normal cerebellar hemispheres but significant abnormalities in the cerebellar vermis, including the molar tooth sign and polydactyly, suggesting JS. The fetal MRI confirmed these findings. Following specialist consultations, the patient opted to terminate the pregnancy. A stillborn female infant was delivered, and genomic DNA sequencing identified a frameshift deletion in the AHI1 gene. Early prenatal diagnosis of JS is crucial for informed pregnancy management. The combination of ultrasonography, MRI, and genomic DNA sequencing proved effective for diagnosis.

Objective To explore the effect of KIAA0753 on glucose and energy metabolism in mouse embryonic osteoblast precursor cell line MC3T3-E1. Methods The GSE182286 datasets of patients with Joubert syndrome acquired from the Gene Expression Comprehensive database were analyzed for the levels of gene expression. After the cells with KIAA0753 overexpression were constructed and the experiment were divided into the control group, the high glucose group and the high glucose+overexpression KIAA0753 group, Western blotting was used to determine the effect of KIAA0753 on MC3T3-E1 cells under high glucose condition by detecting the expression of the glucose metabolism-related proteins, such as glycogen synthase 1 (GYS1), glycogen phosphorylase L (PYGL), glucose transporter type 4(GluT4), phosphofructokinase muscle (PFKM), pyruvate dehydrogenase phosphatase 1 (PDP1), and acetyl-CoA carboxylase α (ACACA), as well as the mitochondria function-associated proteins, including peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α), nuclear respiratory factor 1 (NRF1), and mitochondrial transcription factor A (TFAM). The effect of KIAA0753 on the intermediates of glucose metabolism was analyzed by determining the contents of glycogen, glucose and lactic acid in the cell culture medium. Cellular immunofluorescence assay and adenosine triphosphate (ATP) assay were employed to measure the mitochondrial activity and function impacted by KIAA0753 in the cells under high glucose condition. The effect of KIAA0753 on the proliferation of MC3T3-E1 cells under high glucose was detected by EdU staining. Results The expression of KIAA0753 protein was downregulated in patients with Joubert syndrome and in MC3T3-E1 cells under high glucose conditions (P < 0.05). High glucose resulted in inhibited protein expression of GYS1, ACACA, PFKM, GluT4, PGC-1α, TFAM and NRF1, enhanced protein levels of PDP1 and PYGL, reduced glycogen generation and consumption of extracellular glucose, and promoted production of lactic acid (P < 0.05). While, overexpression of KIAA0753 could attenuate the effect of high glucose, that is, up-regulating the protein expression levels of GYS1, ACACA, PFKM, GluT4, PGC-1α, TFAM and NRF1, suppressing those of PDP1 and PYGL, enhancing glycogen generation and consumption of extracellular glucose, and inhibiting production of lactic acid (P < 0.05). What's more, the overexpression also could elevate the activity and membrane potential of mitochondria, and promote the ATP synthesis (P < 0.05) and cell proliferation (P < 0.05) in MC3T3-E1 cells under high glucose. Conclusion KIAA0753 can promote glucose metabolism and improve mitochondrial activity and function in osteoblasts, consequently providing more energy to the body.

Biallelic SUFU variants have originally been linked to Joubert syndrome, comprising cerebellar abnormalities, dysmorphism, and polydactyly. In contrast, heterozygous truncating variants have recently been associated with developmental delay and ocular motor apraxia, but only a limited number of patients have been reported. Here, we aim to delineate further the mild end of the phenotypic spectrum related to SUFU haploinsufficiency. Nine individuals (from three unrelated families) harboring truncating SUFU variants were investigated, including two previously reported individuals (from one family). We provide results from a comprehensive assessment comprising neuroimaging, neuropsychology, video-oculography, and genetic testing. We identified three inherited or de novo truncating variants in SUFU (NM_016169.4): c.895C>T p.(Arg299∗), c.71dup p.(Ala25Glyfs∗23), and c.71del p.(Pro24Argfs∗72). The phenotypic expression showed high variability both between and within families. Clinical features include motor developmental delay (seven of nine), axial hypotonia (five of nine), ocular motor apraxia (three of nine), and cerebellar signs (three of nine). Four of the six reported children had macrocephaly. Neuropsychological and developmental assessments revealed mildly delayed language development in the youngest children, whereas general cognition was normal in all variant carriers. Subtle but characteristic SUFU -related neuroimaging abnormalities (including superior cerebellar dysplasia, abnormalities of the superior cerebellar peduncles, rostrally displaced fastigium, and vermis hypoplasia) were observed in seven of nine individuals. Our data shed further light on the mild but recognizable features of SUFU haploinsufficiency and underline its marked phenotypic variability, even within families. Notably, neurodevelopmental and behavioral abnormalities are mild compared with Joubert syndrome and seem to be well compensated over time. [ABSTRACT FROM AUTHOR]

Ciliopathies are a diverse group of disorders resulting from abnormalities in the development or function of multiple organs. While significant research has clarified the role of the primary cilium in transducing numerous signalling pathways, elucidating causes of neuronal and skeletal development disorders, the origins of other ciliopathy-related conditions, such as hepatic fibrocystic diseases, remain elusive. Additionally, attempts to correlate specific ciliary proteins with distinct phenotypes have been largely unsuccessful due to the variable and overlapping symptoms of ciliopathies. This study aims to elucidate the extraciliary roles of the protein B9D2 in the development of biliary dysgenesis, a condition present in Meckel-Gruber and Joubert syndromes caused by mutations in this protein. Traditionally, B9D2 is known for its role at the transition zone of the primary cilium in the transduction of signalling pathways notably Wingless and Hedgehog. Our work demonstrates that before ciliogenesis occurs, B9D2 is crucial for the maturation and maintenance of tight junctions ensuring epithelial barrier tightness and appropriate biliary lumen formation. This study provides new insights into the mechanisms underlying biliary dysgenesis in hepatic ciliopathies, suggesting that further exploration of the non-ciliary functions of proteins involved in ciliopathies could lead to a better understanding and treatment of these complex disorders. [ABSTRACT FROM AUTHOR]

Background: Posterior fossa malformation (PFM) is a relatively uncommon prenatal brain malformation. Genetic diagnostic approaches, including chromosome karyotyping, copy number variant (CNV) testing, and whole-exome sequencing (WES), have been applied in several cases of fetal structural malformations. However, the clinical value of appropriate genetic diagnostic approaches for different types of PFMs has not been confirmed. Therefore, in this study, we aimed to analyze the value of different combined genetic diagnostic approaches for various types of fetal PFMs. Methods: This retrospective study was conducted at Beijing Obstetrics and Gynecology Hospital, Capital Medical University, Beijing Maternal and Child Health Care Hospital. Fifty-one pregnant women diagnosed with fetal PFMs who underwent genetic testing in our hospital from January 1, 2017 to December 31, 2022 were enrolled; women with an isolated enlarged cisterna magna were excluded. All participants were categorized into two groups according to the presence of other abnormalities: isolated and non-isolated PFMs groups. Different combined approaches, including karyotype analysis, CNV testing, and trio-based WES, were used for genetic analysis. The detection rates of karyotype analysis, CNV testing, and WES were measured in the isolated and non-isolated groups. Results: In isolated PFMs, pathogenic/likely pathogenic (P/LP) CNVs were detected in four cases (36.36%, 4/11), whereas G-banding karyotyping and WES showed negative results. In non-isolated PFMs, a sequential genetic approach showed a detection rate of 47.5% (19/40); karyotyping revealed aneuploidies in five cases (16.67%, 5/30), CNV testing showed P/LP CNVs in five cases (16.13%, 5/31), and WES identified P/LP variants (in genes CEP20, TMEM67, OFD1, PTPN11, ARID1A, and SMARCA4) in nine cases (40.91%, 9/22). WES showed a detection rate of 83.33% (5/6) in fetuses with Joubert syndrome. Only six patients (five with Blake's pouch cyst and one with unilateral cerebellar hemisphere dysplasia) survived. Conclusions: We recommend CNV testing for fetuses with isolated PFMs. A sequential genetic approach (karyotyping, CNV testing, and WES) may be beneficial in fetuses with non-isolated PFMs. Particularly, we recommend WES as the first-line genetic diagnostic tool for Joubert syndrome. [ABSTRACT FROM AUTHOR]

Introduction: Joubert syndrome a rare genetic disorder, is characterized by abnormalities in the development of the central nervous system with "molar signs" on magnetic resonance imaging of the brain and accompanied by cerebellar vermis hypoplasia, ataxia, hypotonia, and developmental delay. Keratoconus (KC) is a kind of genetically predisposed eye disease that causes blindness characterized by a dilated thinning of the central or paracentral cornea conically projected forward, highly irregular astigmatism, and severe visual impairment. Klinefelter syndrome is caused by an extra X chromosome in the cells of male patients, and the main phenotype is tall stature and dysplasia with secondary sex characteristics. This study was intended to identify the genetic etiology and determine the clinical diagnosis of one Han Chinese family with specific clinical manifestations of keratoconus and multiorgan involvement. Methods: A comprehensive ocular and related general examination was performed on one patient and his asymptomatic parents and brother. Pathogenic genes were tested by exome sequencing. CNV-seq was used to verify the copy number variation, and peripheral blood was cultured for karyotype analysis. The pathogenicity of the identified variant was determined subject to ACMG guidelines. The Gene Expression Omnibus (GEO) dataset of keratoconusrelated genes in the NCBI database was obtained to analyze the differentially expressed genes in corneal tissues of the keratoconus group and the normal control group, and analysis of protein-protein interaction networks (PPI) was performed. Results: Proband, a 25-year-old male, had sudden loss of vision in the left eye for 1 week. Best corrected visual acuity (BCVA): 0.5 (-1.00DS/-5.00DC*29°) in the right eye, counting fingers/40 cm in the left eye. Slit-lamp microscopy of the right eye showed mild anterior protrusion of the cornea and thinning of the conetopped cornea. The left eye showed marked thinning of the central region of the cornea, rounded edema in the form of a cone-like bulge, epithelial bullae, edema and turbidity of the stroma, and bulging of the Descemet's membrane. Cranial magnetic resonance imaging (MRI) revealed changes in the midbrain and cerebellum, with a "molar sign" and a "bat-winged" ventriculus quartus cerebri. General check-up: 168 cm in height, decreased muscle tone in all four limbs, knee jerk elicited, negative Babinski sign, abdominal reflexes elicited, finger-to-nose test positive, intentional tremor evident in both hands, positive Romberg's sign, instability of gait, level I intellectual disability, poor adaptive behavior, communication disorders, teeth all dentures, a peculiar face with blepharophimosis, wide inner canthus distance, mild ptosis, severe positive epicanthus, high palatal arches, exotropia, hypotrichosis of beard and face, inconspicuous prominentia laryngea, and short upper and lower limbs. Exome sequencing detected compound heterozygous frameshift variants M1:c.9279dup: p.His3094Thrfs*18 and M2:c.6515_6522del:p.Lys2172Thrfs*37 in the patient's CPLANE1 gene and the presence of duplication-type CNV on the X chromosome. Sanger sequencing showed that the mother and father carried the M1 and M2 variants, respectively, and the younger brother carried the M2 variant, which was a novel variant. CNV-seq analysis showed the presence of a duplication-type CNV Xp22.33-Xq28 (2757837-156030895) of approximately 155 Mb on the X chromosome of the proband, which was a de novo variant and carried by neither of the parents. The two heterozygous frameshift variants and duplication-type CNV were pathogenic according to the ACMG guidelines. Differential expression analysis of keratoconus-related genes showed that CPLANE1 was upregulated in the corneal tissues of keratoconus patients compared with normal controls, and such a difference was statistically significant (p = 0.000515, <0.05). PPI analysis showed that the CPLANE1-NPHP3 complex protein acted as a bridge between cilia and extracellular matrix tissue. According to the genetic test results and clinical phenotype analysis, the family was finally diagnosed with Joubert syndrome combined with Keratoconus and Klinefelter syndrome. Discussion: In this study, we report a proband in a Han Chinese family with both Joubert syndrome and X-linked Klinefelter syndrome as well as keratoconus, and the phenotype spectrum of CPLANE1-Joubert syndrome may be expanded accordingly. Meanwhile, the significance of exome sequencing was emphasized in aiding the clinical diagnosis of complex cases, which is difficult to make. [ABSTRACT FROM AUTHOR]

KIAA0586 variants have been associated with a wide range of ciliopathies, mainly Joubert syndrome (JS, OMIM #616490) and short-rib thoracic dysplasia syndrome (SRTD, OMIM #616546). However, the hypothesis that this gene is involved with hydrolethalus syndrome (HSL, OMIM #614120) and orofaciodigital syndrome IV (OMIM #258860) has already been raised. Ciliopathies' clinical features are often overlapped despite differing in phenotype severity. Besides KIAA0586, HYLS1 and KIF7 are also known for being causative of ciliopathies, indicating that all three genes may have similar or converging genomic pathways. Overall, the genotypic and phenotypic spectrum of ciliopathies becomes wider and conflicting while more and more new variants are added to this group of disorders' molecular pot. In this case report we discuss the first Brazilian individual clinically diagnosed with hydrolethalus syndrome and molecular findings that demonstrate the role of KIAA0586 as a causative gene of a group of genetic disorders. Also, recent reports on individuals with intronic and exonic variants combined leading to ciliopathies support our patient's molecular diagnosis. At the same time, we discuss variable expressivity and overlapping features in ciliopathies. [ABSTRACT FROM AUTHOR]

Hydrocephalus is rarely described in Joubert‐Boltshauser syndrome (JBTS). The aim of this study was to investigate whether this association is a chance occurrence or potentially signifies a new phenotypic subtype. The databases of Wolfson Medical Center, Sourasky Medical Center, and EB's personal collection were reviewed. Records from an additional family were obtained from RG. The patients' medical records, prenatal ultrasounds, and magnetic resonance imaging were assessed. In addition, we reviewed the medical literature for the association of ventriculomegaly/hydrocephalus (VM/HC) in JBTS. Only seven cases (from five families) were found with prenatal onset of VM/HC, diagnosed during the second trimester; three pregnancies were terminated, one was stillborn and three were born, of which one died within a week, and another died at the age of 6 years. Additional central nervous system findings included dysgenesis of the corpus callosum, delayed sulcation, polymicrogyria, and pachygyria. We found 16 publications describing 54 patients with JBTS and VM/HC: only five were diagnosed at birth and three were diagnosed prenatally. Hydrocephalus is extremely rare in JBTS. The recurrence of this association, reported in several publications in multiple family members, suggests that it might represent a new phenotypic subtype of JBTS possibly associated with specific genes or variants. Further genetic studies are needed to confirm this hypothesis. What this paper adds: The association of fetal hydrocephalus with Joubert‐Boltshauser syndrome (JBTS) is very rare but not a chance association.This association represents a new phenotypic subtype of JBTS possibly linked to specific genes or variants. [ABSTRACT FROM AUTHOR]

Joubert syndrome (JS) is a complex medical condition characterized by a pathognomonic midbrain-hindbrain malformation visible on brain imaging, which is known as the "molar tooth sign" (MTS). The presence of the MTS in the brain is the defining diagnostic criterion for JS. Individuals with JS commonly exhibit a developmental delay, hypotonia, and abnormal eye movements. In addition, neonatal breathing dysregulation is observed in about half of the cases. Midline brain defects associated with JS can lead to pituitary hormone abnormalities, thereby manifesting as multiple pituitary insufficiencies in the neonatal period, such as hypoglycemia and, in male patients, a micropenis with undescended testes. Although JS is a well-researched genetic condition, there is minimal information on the endocrinological aspects of JS. This manuscript aims to emphasize the spectrum of endocrinologic findings in JS through the retrospective evaluation of four cases characterized by combined pituitary dysfunctions, including secondary hypothyroidism, growth hormone deficiency, and panhypopituitarism. Highlighting these treatable aspects of JS is crucial, as continuous endocrinological monitoring can positively impact a patient's well-being, particularly in managing secondary adrenal and thyroid insufficiencies. [ABSTRACT FROM AUTHOR]

Nephronophthisis (NPHP) is an autosomal recessive cystic kidney disease and is one of the most frequent genetic causes for kidney failure (KF) in children and adolescents. Over 20 genes cause NPHP and over 90 genes contribute to renal ciliopathies often involving multiple organs. About 15–20% of NPHP patients have additional extrarenal symptoms affecting other organs than the kidneys. The involvement of additional organ systems in syndromic forms of NPHP is explained by shared expression of most NPHP gene products in centrosomes and primary cilia, a sensory organelle present in most mammalian cells. This finding resulted in the classification of NPHP as a ciliopathy. If extrarenal symptoms are present in addition to NPHP, these disorders are defined as NPHP-related ciliopathies (NPHP-RC) and can involve the retina (e.g., with Senior-Løken syndrome), CNS (central nervous system) (e.g., with Joubert syndrome), liver (e.g., Boichis and Arima syndromes), or bone (e.g., Mainzer-Saldino and Sensenbrenner syndromes). This review focuses on the pathological findings and the recent genetic advances in NPHP and NPHP-RC. Different mechanisms and signaling pathways are involved in NPHP ranging from planar cell polarity, sonic hedgehog signaling (Shh), DNA damage response pathway, Hippo, mTOR, and cAMP signaling. A number of therapeutic interventions appear to be promising, ranging from vasopressin receptor 2 antagonists such as tolvaptan, cyclin-dependent kinase inhibitors such as roscovitine, Hh agonists such as purmorphamine, and mTOR inhibitors such as rapamycin. [ABSTRACT FROM AUTHOR]

Objective: To present three-dimensional reconstruction of agenesis of ductus venosus (ADV) using HDlive Flow in the first trimester of pregnancy. Case description: A 35-year-old pregnant Japanese woman was referred to our ultrasound clinic at 13 weeks and 6 days of gestation because of fetal generalized skin edema. Color Doppler and HDlive Flow revealed ADV. Moreover, HDlive Flow clearly showed the spatial relationships among the descending aorta, umbilical vein, intrahepatic drainage to portal vein, and inferior vena cava. Chromosome analysis using amniocentesis at 16 weeks and 5 days revealed 46, XY. Second-trimester fetal screening at 18 weeks and 5 days showed partial agenesis of the cerebellar vermis (Dandy-Walker variant) and ADV. Magnetic resonance imaging (MRI) confirmed partial agenesis of the cerebellar vermis at 33 weeks and 6 days of gestation. Conclusion: HDlive Flow should be used as an adjunctive modality to diagnose fetal vascular abnormalities such as ADV even in the first trimester of pregnancy. [ABSTRACT FROM AUTHOR]

A hamartoma is a benign proliferation of typical mature cells specific to a particular anatomical site. In the oral cavity, they may occur as isolated cases or be associated with genetic syndromes. Oral‐facial‐digital syndrome type VI is a rare genetic disorder with an estimated incidence of one in 50,000–250,000 newborns. Here, we report a case of a 2‐year‐old boy diagnosed with oral‐facial‐digital syndrome type VI who was referred for evaluation of a bilateral and normochromic to slightly pinkish nodule on the lateral surface of the tongue. Clinically, the child presented hypotonia, low visual acuity, absence of oculocephalic reflex, delay in neuropsychomotor development, and polydactyly in the feet. Excisional biopsies of both sides of the tongue were performed using a 1.5 W high‐power diode laser (wavelength of 980 nm), and histopathological analysis revealed abundant mature adipocytes predominantly arranged in lobules that mainly surrounded the minor salivary gland parenchyma. The surgical sites healed with no complications and the patient remains under follow‐up for 10 months. Due to the limited literature on this syndrome and the frequent presence of tongue hamartomas in children, dentists need to be familiar with them. [ABSTRACT FROM AUTHOR]

Joubert syndrome (JS), a rare neurodevelopmental disorder, is characterized by a unique midbrainhindbrain malformation known as the molar tooth sign, a distinctive radiological feature. Among the myriad manifestations associated with JS, the most prevalent features encompass hypotonia, ataxia, developmental delay, intellectual disability, abnormal eye movements, and neonatal breathing abnormalities. To date, 29 genes have been identified as contributors to the development of JS. This study aimed to pinpoint a pathogenic variant in JS within an Iranian consanguineous pedigree. We employed whole-exome sequencing (WES) to pinpoint a potential pathogenic variant likely responsible for the condition in an 8-year-old male patient. The WES analysis successfully revealed a novel homozygous missense mutation (c.725A>T; p.Asn242Ile) within exon 8 (NM_153704.6) of the TMEM67 gene. Subsequent validation through Sanger sequencing confirmed the presence of the chr8-93780603A>T mutation. This study elucidated JS within an Iranian family, uncovering a new TMEM67 gene mutation through comprehensive genetic analysis. The identification of this mutation enhances our understanding of the genetic landscape of JS, contributing valuable insights for both clinical diagnosis and future research endeavors. [ABSTRACT FROM AUTHOR]

Abstract Background Syndromic ciliopathies are a group of congenital disorders characterized by broad clinical and genetic overlap, including obesity, visual problems, skeletal anomalies, mental retardation, and renal diseases. The hallmark of the pathophysiology among these disorders is defective ciliary functions or formation. Many different genes have been implicated in the pathogenesis of these diseases, but some patients still remain unclear about their genotypes. Methods The aim of this study was to identify the genetic causes in patients with syndromic ciliopathy. Patients suspected of or meeting clinical diagnostic criteria for any type of syndromic ciliopathy were recruited at a single diagnostic medical center in Southern Taiwan. Whole exome sequencing (WES) was employed to identify their genotypes and elucidate the mutation spectrum in Taiwanese patients with syndromic ciliopathy. Clinical information was collected at the time of patient enrollment. Results A total of 14 cases were molecularly diagnosed with syndromic ciliopathy. Among these cases, 10 had Bardet-Biedl syndrome (BBS), comprising eight BBS2 patients and two BBS7 patients. Additionally, two cases were diagnosed with Alström syndrome, one with Oral-facial-digital syndrome type 14, and another with Joubert syndrome type 10. A total of 4 novel variants were identified. A recurrent splice site mutation, BBS2: c.534 + 1G > T, was present in all eight BBS2 patients, suggesting a founder effect. One BBS2 patient with homozygous c.534 + 1G > T mutations carried a third ciliopathic allele, TTC21B: c.264_267dupTAGA, a nonsense mutation resulting in a premature stop codon and protein truncation. Conclusions Whole exome sequencing (WES) assists in identifying molecular pathogenic variants in ciliopathic patients, as well as the genetic hotspot mutations in specific populations. It should be considered as the first-line genetic testing for heterogeneous disorders characterized by the involvement of multiple genes and diverse clinical manifestations.

Joubert sendromu nadir görülen, psikomotor gelişme geriliği, nistagmus, ataksi ve tekrarlayan takipne-apne nöbetleri ile karakterize otozomal resesif geçişli bir hastalıktır. Mikrosefali, polidaktili, retina displazisi, böbrek kistleri ve dil tümörleri sendroma eşlik edebilen anomalilerdir. Joubert sendromlu hastalarda değişen derecelerde serebellar vermis displazisi görülür. Bu çocuklarda anestezi uygulanması perioperatif solunum problemleri ile komplike olabilir. Kranial magnetik rezonans görüntülemede serebellar vermis hipoplazisinin neden olduğu molar diş görüntüsü nöroradyolojik tanı kriteridir. Bu yazıda Joubert sendromlu bir hastada diş tedavisi sırasında anestezi yönetimimiz sunulmaktadır.

Joubert syndrome (JS) is a recessively inherited congenital ataxia characterized by hypotonia, psychomotor delay, abnormal ocular movements, intellectual disability, and a peculiar cerebellar and brainstem malformation, the "molar tooth sign." Over 40 causative genes have been reported, all encoding for proteins implicated in the structure or functioning of the primary cilium, a subcellular organelle widely present in embryonic and adult tissues. In this paper, we developed an in vitro neuronal differentiation model using patient-derived induced pluripotent stem cells (iPSCs), to evaluate possible neurodevelopmental defects in JS. To this end, iPSCs from four JS patients harboring mutations in distinct JS genes (AHI1, CPLANE1, TMEM67, and CC2D2A) were differentiated alongside healthy control cells to obtain mid-hindbrain precursors and cerebellar granule cells. Differentiation was monitored over 31 days through the detection of lineage-specific marker expression by qRT-PCR, immunofluorescence, and transcriptomics analysis. All JS patient-derived iPSCs, regardless of the mutant gene, showed a similar impairment to differentiate into mid-hindbrain and cerebellar granule cells when compared to healthy controls. In addition, analysis of primary cilium count and morphology showed notable ciliary defects in all differentiating JS patient-derived iPSCs compared to controls. These results confirm that patient-derived iPSCs are an accessible and relevant in vitro model to analyze cellular phenotypes connected to the presence of JS gene mutations in a neuronal context. [ABSTRACT FROM AUTHOR]

Genetic disorders are common in Saudi Arabia. Impaired motor development is one of the major characteristics associated with genetic disorders. Early identifications and referrals are key to receiving physical therapy. This study aims to explore caregivers of children with genetic disorders' experience with early identification and referrals to physical therapy. An inductive qualitative design of 16 caregivers of children with genetic disorders was done to investigate the identification and referral process to physical therapy. A thematic analysis was used to analyze the data and multiple coders coded the data to increase the trustworthiness of the analysis. The analysis led to emergence of four main themes. Caregivers revealed their struggle with the detection process. They struggled with the vague information related to their children's condition. They also expressed a desperate need for guidance to clarify the process for genetic testing, counseling, and rehabilitation. Although their overall experience with physical therapy was satisfactory, they encountered a number of issues related to scheduling appointments, delayed referrals, and unconfirmed diagnoses. The results of this study could indicate that more efforts are required to expedite and elucidate the identification and referral of children with genetic disorders in Saudi Arabia. The process of referring children with genetic disorders to physical therapy (PT) is not clearly understood by caregivers. Providing caregivers with information about the benefits of PT for children with genetic disorders is needed to encourage adherence to PT sessions and rehabilitation plan. Caregivers expressed the need for further education on the wide spectrum of genetic disorders. Caregivers experienced costly and lengthy genetic testing process that often lead to inconclusive results which could delay the referral process. Alternative solutions should be considered to provide these children with early access to rehabilitation services including PT. One of these solutions could be implementing regular screening and monitoring as well as parent education to aid in detecting delays and expedite the referral process. [ABSTRACT FROM AUTHOR]

To investigate midbrain growth, including corpus callusum (CC) and cerebellar vermis (CV) and cortical development in late fetal growth restricted (FGR) subclassified according to the umbilical vein blood flow (UVBF) values. This was a prospective study on singleton fetuses late FGR with abnormal placental cerebral ratio (PCR). FGR fetuses were further subdivided into normal (≥fifth centile) and abnormal (

Background: Syndromic ciliopathies are a group of congenital disorders characterized by broad clinical and genetic overlap, including obesity, visual problems, skeletal anomalies, mental retardation, and renal diseases. The hallmark of the pathophysiology among these disorders is defective ciliary functions or formation. Many different genes have been implicated in the pathogenesis of these diseases, but some patients still remain unclear about their genotypes. Methods: The aim of this study was to identify the genetic causes in patients with syndromic ciliopathy. Patients suspected of or meeting clinical diagnostic criteria for any type of syndromic ciliopathy were recruited at a single diagnostic medical center in Southern Taiwan. Whole exome sequencing (WES) was employed to identify their genotypes and elucidate the mutation spectrum in Taiwanese patients with syndromic ciliopathy. Clinical information was collected at the time of patient enrollment. Results: A total of 14 cases were molecularly diagnosed with syndromic ciliopathy. Among these cases, 10 had Bardet-Biedl syndrome (BBS), comprising eight BBS2 patients and two BBS7 patients. Additionally, two cases were diagnosed with Alström syndrome, one with Oral-facial-digital syndrome type 14, and another with Joubert syndrome type 10. A total of 4 novel variants were identified. A recurrent splice site mutation, BBS2: c.534 + 1G > T, was present in all eight BBS2 patients, suggesting a founder effect. One BBS2 patient with homozygous c.534 + 1G > T mutations carried a third ciliopathic allele, TTC21B: c.264_267dupTAGA, a nonsense mutation resulting in a premature stop codon and protein truncation. Conclusions: Whole exome sequencing (WES) assists in identifying molecular pathogenic variants in ciliopathic patients, as well as the genetic hotspot mutations in specific populations. It should be considered as the first-line genetic testing for heterogeneous disorders characterized by the involvement of multiple genes and diverse clinical manifestations. [ABSTRACT FROM AUTHOR]

Background: This report presents a clinical case of syndromic rod-cone dystrophy due to a splice site variant in the ARL2BP gene causing situs inversus, asthenozoospermia, unilateral renal agenesis and microcysts. The presence of renal agenesis and cryptorchidism expands the clinical manifestations due to ARL2BP variants. The detailed, long-term follow-up contributes valuable insights into disease progression, aiding clinical diagnosis and patient management. Case Presentation: The male patient complained of photophobia as the first symptom when he was 20 years old followed by nyctalopia, loss of central visual acuity and peripheral visual field ten years later. Genetic analysis identified a likely pathogenic homozygous variant (c.294-1G > C) involving the splicing acceptor site of intron 4. Reported symptoms together with full-field stimulus threshold testing, electroretinogram and advanced multimodal imaging allowed us to recognize the typical characteristics of a mixed retinal dystrophy. Despite the end-stage retinal disease, this patient still retained a useful residual vision at 63 years and had a slow disease progression during the last 5 years of evaluation. Discussion and conclusions: Our findings underscore the variable clinical presentation of ARL2BP variants, emphasizing the importance of a nuanced approach in diagnosing and managing patients. The presence of renal cysts warrants consideration of a differential diagnosis, particularly with Senior-Loken (SLS), Bardet-Biedl (BBS) and Joubert syndromes (JS) but also with Short Rib Thoracic Dysplasia 9, highlighting the need for careful phenotypic evaluation in these cases. [ABSTRACT FROM AUTHOR]

Joubert syndrome (JBTS) is a systematic developmental disorder mainly characterized by a pathognomonic mid‐hindbrain malformation. All known JBTS‐associated genes encode proteins involved in the function of antenna‐like cellular organelle, primary cilium, which plays essential roles in cellular signal transduction and development. Here, we identified four unreported variants in ARL13B in two patients with the classical features of JBTS. ARL13B is a member of the Ras GTPase family and functions in ciliogenesis and cilia‐related signaling. The two missense variants in ARL13B harbored the substitutions of amino acids at evolutionarily conserved positions. Using model cell lines, we found that the accumulations of the missense variants in cilia were impaired and the variants showed attenuated functions in ciliogenesis or the trafficking of INPP5E. Overall, these findings expanded the ARL13B pathogenetic variant spectrum of JBTS. [ABSTRACT FROM AUTHOR]

The neuropsychological characteristics of the cerebellar cognitive affective syndrome (CCAS) in congenital, non-progressive malformations of the cerebellum have been scarcely investigated, and even less is known for Joubert syndrome (JS), an inherited, non-progressive cerebellar ataxia characterized by the so-called molar tooth sign. The few studies on this topic reported inconsistent results about intellectual functioning and specific neuropsychological impairments. The aim of this research is to examine the neuropsychological profile of JS compared to other congenital cerebellar malformations (CM), considering individual variability of intellectual quotient (IQ) in the two groups. Fourteen patients with JS and 15 patients with CM aged 6-25 years were tested through a comprehensive, standardized neuropsychological battery. Their scores in the neuropsychological domains were inspected through descriptive analysis and compared by mean of MANOVA and ANOVA models, then replicated inserting IQ as covariate. The two groups showed a largely overlapping neuropsychological profile, consistent with CCAS. However, the JS group showed worse performance in visual-spatial memory compared to CM patients, although this difference was mitigated when considering IQ. These findings highlight a divergence between JS and other CM in visual-spatial memory, which might suggest a critical role of the cerebellum in recalling task-relevant memories and might inform rehabilitative interventions. [ABSTRACT FROM AUTHOR]

Introduction: Pediatric cystic kidney disease (CyKD) includes conditions characterized by renal cysts. Despite extensive research in this field, there are no reliable genetics or other biomarkers to estimate the phenotypic consequences. Therefore, CyKD in children heavily relies on clinical and diagnostic testing to predict the long-term outcomes. Aim: A retrospective study aimed to provide a concise overview of this condition and analyze real-life data from a single-center pediatric CyKD cohort followed during a 12-year period. Methods and Materials: Medical records were reviewed for extensive clinical, laboratory, and radiological data, treatment approaches, and long-term outcomes. Results: During the study period, 112 patients received a diagnosis of pediatric CyKD. Male patients were more involved than female (1:0.93). Fifty-six patients had a multicystic dysplastic kidney; twenty-one of them had an autosomal dominant disorder; fifteen had an isolated renal cyst; ten had been diagnosed with autosomal recessive polycystic kidney disease; three had the tuberous sclerosis complex; two patients each had Bardet–Biedl, Joubert syndrome, and nephronophthisis; and one had been diagnosed with the trisomy 13 condition. Genetic testing was performed in 17.9% of the patients, revealing disease-causing mutations in three-quarters (75.0%) of the tested patients. The most commonly presenting symptoms were abdominal distension (21.4%), abdominal pain (15.2%), and oligohydramnios (12.5%). Recurrent urinary tract infections (UTI) were documented in one-quarter of the patients, while 20.5% of them developed hypertension during the long-term follow-up. Antibiotic prophylaxis and antihypertensive treatment were the most employed therapeutic modalities. Seventeen patients progressed to chronic kidney disease (CKD), with thirteen of them eventually reaching end-stage renal disease (ESRD). The time from the initial detection of cysts on an ultrasound (US) to the onset of CKD across the entire cohort was 59.0 (7.0–31124.0) months, whereas the duration from the detection of cysts on an US to the onset of ESRD across the whole cohort was 127.0 (33.0–141.0) months. The median follow-up duration in the cohort was 3.0 (1.0–7.0) years. The patients who progressed to ESRD had clinical symptoms at the time of initial clinical presentation. Conclusion: This study is the first large cohort of patients reported from Croatia. The most common CyKD was the multicystic dysplastic kidney disease. The most common clinical presentation was abdominal distention, abdominal pain, and oliguria. The most common long-term complications were recurrent UTIs, hypertension, CKD, and ESRD. [ABSTRACT FROM AUTHOR]

Aim: To describe visual function in children with Joubert syndrome and to investigate its possible association with diagnostic and developmental aspects. Method: This retrospective cross‐sectional work included 59 patients (33 male; mean age 9 years 2 months, standard deviation 6 years 3 months, range 4 months to 23 years) diagnosed with Joubert syndrome from January 2002 to December 2020. Data about clinical (neurological, neuro‐ophthalmological, developmental/cognitive) and diagnostic (e.g. genetic testing, neuroimaging, systemic involvement) evaluations were collected in a data set during a review of medical records. Clinical and diagnostic variables were described in terms of raw counts and percentages. A χ2 test was conducted to investigate their association with neuropsychological skills. Results: Ocular motor apraxia was highly represented in our cohort (75%), with a high prevalence of refractive defects and retinal abnormalities. Developmental delay/intellectual disability was frequent (in 69.5% of the sample), associated with retinal dystrophy (p = 0.047) and reduced visual acuity both for near (p = 0.014) and for far distances (p = 0.017). Interpretation: On the basis of the relevance of oculomotor and perceptual alterations and their impact on overall and cognitive impairment, we encourage early and multidisciplinary assessment and follow‐up of visual function in children with Joubert syndrome. This would help in planning a personalized rehabilitation to sustain functional vision. Further studies will be important to explore the link between biological aspects and global functioning in children with Joubert syndrome. What this paper adds: Perceptual deficits and oculomotor impairments frequently coexist in Joubert syndrome.Retinal dysfunction may be present despite the absence of funduscopic abnormalities.Both perceptual and oculomotor impairments negatively affect cognitive development in Joubert syndrome. What this paper adds: Perceptual deficits and oculomotor impairments frequently coexist in Joubert syndrome.Retinal dysfunction may be present despite the absence of funduscopic abnormalities.Both perceptual and oculomotor impairments negatively affect cognitive development in Joubert syndrome. [ABSTRACT FROM AUTHOR]

Cilia are organelles extend from cells to sense external signals for tuning intracellular signaling for optimal cellular functioning. They have evolved sensory and motor roles in various cells for tissue organization and homeostasis in development and post-development. More than a thousand genes are required for cilia function. Mutations in them cause multisystem disorders termed ciliopathies. The null mutations in CC2D2A result in Meckel syndrome (MKS), which is embryonic lethal, whereas patients who have missense mutations in the C2 domain of CC2D2A display Joubert syndrome (JBTS). They survive with blindness and mental retardation. How C2 domain defects cause disease conditions is not understood. To answer this question, C2 domain of Cc2d2a (mice gene) was knocked down (KD) in IMCD-3 cells by shRNA. This resulted in defective cilia morphology observed by immunofluorescence analysis. To further probe the cellular signaling alteration in affected cells, gene expression profiling was done by RNAseq and compared with the controls. Bioinformatics analysis revealed that the differentially expressed genes (DEGs) have functions in cilia. Among the 61 cilia DEGs identified, 50 genes were downregulated and 11 genes were upregulated. These cilia genes are involved in cilium assembly, protein trafficking to the cilium, intraflagellar transport (IFT), cellular signaling like polarity patterning, and Hedgehog signaling pathway. This suggests that the C2 domain of CC2D2A plays a critical role in cilia assembly and molecular signaling hosted in cilia for cellular homeostasis. Taken together, the missense mutations in the C2 domain of CC2D2A seen in JBTS might have affected cilia-mediated signaling in neurons of the retina and brain. [ABSTRACT FROM AUTHOR]

Background: The fetal monogenic causes of early pregnancy losses (EPLs) are mainly unknown, with only a few articles on the subject published. In our previous study of EPLs using whole-exome sequencing analysis, we confirmed a genetic diagnosis of CPLANE1-related Joubert syndrome (JS) in three EPLs from two couples and identified a relatively common CPLANE1 allele among our population (NM_001384732.1:c.1819delT;c.7817T>A, further after referred as "complex allele"). Pathogenic variants in the CPLANE1 (C5orf42) gene are reported to cause JS type 17, a primary ciliopathy with various system defects. Aims: To examine the hypothesis that the CPLANE1 "complex allele," whether homozygous or compound heterozygous, is a common cause of EPLs in our population. Study Design: Cohort study/case-control study. Methods: In this study, we used polymerase chain reaction-based methods to screen for CPLANE1 "complex allele" presence among 246 euploid EPLs (< 12 gestational weeks) from families in North Macedonia. We also investigated the impact of this allele in 650 women with EPLs versus 646 women with no history of pregnancy loss and at least one livebirth, matched by ethnic origin. Results: We found a high incidence of JS in the total study group of EPLs (2.03%), with a considerably higher incidence among Albanian families (6.25%). Although not statistically significant, women with EPLs had a higher allele frequency of the CPLANE1 "complex allele" (AF = 1.38%) than the controls (AF = 0.85%; p = 0.2). Albanian women had significantly higher frequency of the "complex allele" than the Macedonians (AF = 1.65% and 0.39%, respectively; p = 0.003). Conclusion: To the best of our knowledge, this is the highest reported incidence of fetal monogenic disease that might cause EPLs. Targeted screening for the CPLANE1 "complex allele" would be warranted in Albanian ethnic couples because it would detect one JS in every 16 euploid EPLs. Our findings have a larger impact on the pathogenesis of pregnancy loss and contribute to a better understanding of the pathogenicity of the variants in the CPLANE1 gene. [ABSTRACT FROM AUTHOR]

Abstract Background Joubert syndrome (JS) is a rare genetically heterogeneous primary ciliopathy characterized by a pathognomonic cerebellar and brainstem malformation, the “molar tooth sign”, and variable organ involvement (such as eye, kidney, liver, and skeleton). Here, we present a case of JS in a Chinese boy. Case presentation An 11-year-old Chinese boy presented with neonatal asphyxiation and hypoxia, strabismus, subsequent developmental delay, ataxia and end-stage kidney disease (ESKD). Routine blood tests showed severe anemia, increasing blood urea nitrogen and creatinine, elevated parathyroid hormone, hypocalcemia, hypokalemia and metabolic acidosis. Urine tests showed mild proteinuria. Ultrasound showed two small kidneys. Brain magnetic resonance imaging (MRI) showed dysplasia of the cerebellar vermis and extension of the upper cerebellar feet with the “molar tooth sign”. Genetic analysis showed novel compound heterozygous mutations in the RPGRIP1L gene [p.L447fs*7(p.Leu447fsTer7) and p.G908V (p.Gly908Val)]. Conclusion In the present study, we identified novel compound heterozygous mutations in the RPGRIP1L gene in a Chinese boy. The clinical and genetic findings of this study will expand the understanding of JS.

Abstract Background Joubert syndrome (JS) is a group of rare ciliopathies, mainly characterized by cerebellar dysplasia representing the “molar tooth sign (MTS)” on neuroimaging, hypotonia, and developmental delay. Having a complicated genotype-phenotype correlation due to its rich genetic heterogeneity, JS is usually combined with other organic defects affecting the retina, kidney, and liver. This report aimed to present new cases and novel variants of JS. Case presentation Five unrelated patients who were diagnosed with JS, with or without typical clinical characteristics, received integrated examinations, including whole-exome sequencing (WES) and Sanger sequencing. We identified nine pathogenic variants in the TCTN2, CPLANE1, INPP5E, NPHP1, and CC2D2A genes. Conclusion Four novel pathogenic mutations in the TCTN2, CPLANE1, and INPP5E genes were reported. The findings broadened the genotypic spectrum of JS and contributed to a better understanding of genotype-phenotype correlation.

Joubert syndrome (JBTS) is a rare autosomal recessive or X-linked congenital brain malformation with strong genetic heterogeneity. Other neurological features of JBTS include hypotonia, ataxia, developmental delay, and cognitive impairment. Hearing loss with JBTS has been reported in the literature. We present the case of a 3.5-year-old boy born to a healthy consanguineous South Indian couple who was presented with ataxic cerebral palsy (CP) and hearing impairment; medical reports confirmed typical brain malformations of JBTS. Hearing impairment was screened by audiological assessment, which confirmed the presence of severe-profound hearing loss with outer hair cell dysfunction. Whole-exome sequencing (WES) was performed to know the molecular aspects of the condition and to detect any novel mutations. The homozygous mutation AHI1 c.2023G > A associated with JBTS type 3 and GJB2 c.71G > A mutation associated with hearing impairment were identified. Sanger sequencing was performed to validate the result and it identified heterozygous AHI1 c.2023G > A and GJB2 c.71G > A in the patient's parents. This study confirms the diagnosis of JBTS by WES helps identify the genetic causes of hereditary disorders that accelerate genetic evaluation and counseling for at-risk families.

Joubert syndrome (JS) is a rare autosomal recessive neurodevelopmental condition characterized by congenital mid-hindbrain abnormalities and a variety of clinical manifestations. This article describes a case of Joubert syndrome type 21 with microcephaly, seizures, developmental delay and language regression, caused by a CSPP1 gene variant and examines the contributing variables. This paper advances the understanding of JS by summarizing the literature and offering detection patterns for practitioners with clinical suspicions of JS.

Background: COACH syndrome is a rare autosomal recessive genetic disease characterized by liver fibrosis, which leads to severe complications related to portal hypertension. However, only a few patients with COACH syndrome undergoing liver transplantation (LT) have been reported. Materials and Methods: We herein report the outcomes of four children who underwent LT for COACH syndrome at our institute and review three previously reported cases to elucidate the role of LT in COACH syndrome. Results: All four patients in our institute were female, and three received living donors LT. All patients were diagnosed with COACH syndrome by genetic testing. LT was performed in these patients at 3, 7, 9, and 14 years old. The indication for LT was varices related to portal hypertension in all patients. One showed an intrapulmonary shunt. Blood tests revealed renal impairment due to nephronophthisis in three patients, and one developed renal insufficiency after LT. The liver function was maintained in all patients. A literature review revealed detailed information for three more patients. The indication for LT in these three cases was portal hypertension, such as bleeding from esophageal varices. One patient had chronic renal failure on hemodialysis at LT and underwent combined liver and kidney transplantation. Of these three previous patients, one died from hepatic failure due to de novo HCV infection 3 years after LT. Conclusions: LT should be considered an effective treatment for COACH syndrome in patients with severe portal hypertension. However, a detailed follow‐up of the renal function is necessary. [ABSTRACT FROM AUTHOR]

This retrospective study examines the clinical characteristics and underlying genetic variants that exist in a Leber congenital amaurosis (LCA) patient cohort evaluated at the inherited retinal disease (IRD) clinic at the University of Minnesota (UMN)/M Health System. Our LCA cohort consisted of 33 non-syndromic patients and one patient with Joubert syndrome. We report their relevant history, clinical findings, and genetic testing results. We monitored disease presentation utilizing ocular coherence tomography (OCT) and fundus autofluorescence (FAF). Electroretinogram testing (ERG) was performed in patients when clinically indicated. Next-generation sequencing (NGS) and genetic counseling was offered to all evaluated patients. Advanced photoreceptor loss was noted in 85.7% of the subjects. All patients who underwent FAF had findings of either a ring of macular hypo/hyper AF or peripheral hypo-AF. All patients had abnormal ERG findings. A diagnostic genetic test result was identified in 74.2% of the patients via NGS single-gene testing or panel testing. Two patients in our cohort qualified for Luxturna® and both received treatment at the time of this study. These data will help IRD specialists to understand the genetic variants and clinical presentations that characterize our patient population in the Midwest region of the United States. [ABSTRACT FROM AUTHOR]

Aurora Kinase A (AURKA) promotes cell proliferation and is overexpressed in different types of polycystic kidney disease (PKD). To understand AURKA's role in regulating renal cyst development we conditionally deleted the gene in mouse models of Autosomal Dominant PKD (ADPKD) and Joubert Syndrome, caused by Polycystin 1 (Pkd1) and Inositol polyphosphate-5-phosphatase E (Inpp5e) mutations respectively. We show that while Aurka is dispensable for collecting duct development and homeostasis, its deletion prevents cyst formation in both disease models. Cross-comparison of transcriptional changes implicated AKT signaling in cyst prevention and we show that (i) AURKA and AKT physically interact, (ii) AURKA regulates AKT activity in a kinase-independent manner and (iii) inhibition of AKT can reduce disease severity. AKT activation also regulates Aurka expression, creating a feed-forward loop driving renal cystogenesis. We find that the AURKA kinase inhibitor Alisertib stabilises the AURKA protein, agonizing its cystogenic functions. These studies identify AURKA as a master regulator of renal cyst development in different types of PKD, functioning in-part via AKT. Using different mouse models of Polycystic Kidney Disease, this research demonstrated that deletion of the Aurora Kinase A gene was able to prevent cyst initiation and growth, identifying it as a central regulator of pathogenesis in this condition. [ABSTRACT FROM AUTHOR]

Introduction: Joubert syndrome (JS) arises from defects of primary cilia resulting in potential malformations of the brain, kidneys, eyes, liver, and limbs. Several of the 35+ genes associated with JS have recognized genotype/phenotype correlations, but most genes have not had enough reported individuals to draw meaningful conclusions. Methods: A PubMed literature review identified 688 individuals with JS across 32 genes and 112 publications to bolster known genotype/phenotype relationships and identify new correlations. All included patients had the "molar tooth sign" and a confirmed genetic diagnosis. Individuals were categorized by age, ethnicity, sex and the presence of developmental disability/intellectual disability, hypotonia, abnormal eye movements, ataxia, visual impairment, renal impairment, polydactyly, and liver abnormalities. Results: Most genes demonstrated unique phenotypic profiles. Grouping proteins based on physiologic interactions established stronger phenotypic relationships that reflect known ciliary pathophysiology. Age‐stratified data demonstrated that end‐organ disease is progressive in JS. Most genes demonstrated a significant skew towards having variants with either residual protein function or no residual protein function. Conclusion: This cohort demonstrates that clinically meaningful genotype/phenotype relationships exist within most JS‐related genes and can be referenced to allow for more personalized clinical care. [ABSTRACT FROM AUTHOR]

Copy number variation (CNV) is a primary source of structural variation in the human genome, leading to several disorders. Therefore, analyzing neonatal CNVs is crucial for managing CNV-related chromosomal disabilities. However, genomic waves can hinder accurate CNV analysis. To mitigate the influences of the waves, we adopted a machine learning approach and developed a new method that uses a modified log R ratio instead of the commonly used log R ratio. Validation results using samples with known CNVs demonstrated the superior performance of our method. We analyzed a total of 16,046 Korean newborn samples using the new method and identified CNVs related to 39 genetic disorders were identified in 342 cases. The most frequently detected CNV-related disorder was Joubert syndrome 4. The accuracy of our method was further confirmed by analyzing a subset of the detected results using NGS and comparing them with our results. The utilization of a genome-wide single nucleotide polymorphism array with wave offset was shown to be a powerful method for identifying CNVs in neonatal cases. The accurate screening and the ability to identify various disease susceptibilities offered by our new method could facilitate the identification of CNV-associated chromosomal disease etiologies. [ABSTRACT FROM AUTHOR]