Jeune syndrome: description of 13 cases and a proposal for follow-up protocol

Early-onset renal dysfunction in Jeune syndrome: A case report with atypical presentation

Jeune syndrome, a rare autosomal recessive disorder, is characterized by skeletal abnormalities, particularly a narrow, bell-shaped chest, leading to severe respiratory distress in newborns. This case report details a full-term female neonate presenting with significant respiratory challenges, typical skeletal features, and early-onset renal dysfunction. Despite normal initial imaging, persistent renal abnormalities were observed, underscoring the need for early diagnosis, vigilant monitoring, and a multidisciplinary management approach to optimize outcomes for patients with Jeune syndrome.

Exocrine Pancreatic Insufficiency in Children - Challenges in Management

Cystic fibrosis (CF) is the leading etiology for exocrine pancreatic insufficiency (EPI) in children, followed by chronic pancreatitis, Shwachman-Diamond syndrome, and other genetic disorders. Management of EPI in children poses several unique challenges such as difficulties in early recognition, lack of widespread availability of diagnostic tests and limited number of pediatric-specific pancreatic centers. Pancreatic enzyme replacement therapy is the cornerstone of EPI management and in young children difficulties in administering pancreatic enzymes are frequently encountered. Patients with EPI also should be screened for fat-soluble vitamin deficiencies and receive appropriate supplementation. Among disorders with EPI in children, CF is the relatively well-studied condition, and most management recommendations for EPI in children come from expert consensus and conventional practice guidelines. The impact of EPI can be greater in children given their high metabolic demands and rapid growth. Early diagnosis and aggressive management of EPI prevent consequences of complications such as malnutrition, fat-soluble vitamin deficiencies, and poor bone health and improve outcomes. Management by multi-disciplinary team is the key to success.

Cystic Kidney Diseases in Children and Adults: Differences and Gaps in Clinical Management

Cystic kidney diseases, when broadly defined, have a wide differential diagnosis extending from recessive diseases with a prenatal or pediatric diagnosis, to the most common autosomal-dominant polycystic kidney disease primarily affecting adults, and several other genetic or acquired etiologies that can manifest with kidney cysts. The most likely diagnoses to consider when assessing a patient with cystic kidney disease differ depending on family history, age stratum, radiologic characteristics, and extrarenal features. Accurate identification of the underlying condition is crucial to estimate the prognosis and initiate the appropriate management, identification of extrarenal manifestations, and counseling on recurrence risk in future pregnancies. There are significant differences in the clinical approach to investigating and managing kidney cysts in children compared with adults. Next-generation sequencing has revolutionized the diagnosis of inherited disorders of the kidney, despite limitations in access and challenges in interpreting the data. Disease-modifying treatments are lacking in the majority of kidney cystic diseases. For adults with rapid progressive autosomal-dominant polycystic kidney disease, tolvaptan (V2-receptor antagonist) has been approved to slow the rate of decline in kidney function. In this article, we examine the differences in the differential diagnosis and clinical management of cystic kidney disease in children versus adults, and we highlight the progress in molecular diagnostics and therapeutics, as well as some of the gaps meriting further attention.

Effects of spinal deformities on lung development in children: a review

Scoliosis before the age of 5 years is referred to as early-onset scoliosis (EOS). While causes may vary, EOS can potentially affect respiratory function and lung development as children grow. Moreover, scoliosis can lead to thoracic insufficiency syndrome when aggravated or left untreated. Therefore, spinal thoracic deformities often require intervention in early childhood, and solving these problems requires new methods that include the means for both deformity correction and growth maintenance. Therapeutic strategies for preserving the growing spine and thorax include growth rods, vertically expandable titanium artificial ribs, MAGEC rods, braces and casts. The goals of any growth-promoting surgical strategy are to alter the natural history of cardiorespiratory development, limit the progression of underlying spondylarthrosis deformities and minimize negative changes in spondylothorax biomechanics due to the instrumental action of the implant. This review further elucidates EOS in terms of its aetiology, pathogenesis, pathology and treatment.

Molecular diagnosis and novel genes and phenotypes in a pediatric thoracic insufficiency cohort

Thoracic insufficiency syndromes are a genetically and phenotypically heterogeneous group of disorders characterized by congenital abnormalities or progressive deformation of the chest wall and/or vertebrae that result in restrictive lung disease and compromised respiratory capacity. We performed whole exome sequencing on a cohort of 42 children with thoracic insufficiency to elucidate the underlying molecular etiologies of syndromic and non-syndromic thoracic insufficiency and predict extra-skeletal manifestations and disease progression. Molecular diagnosis was established in 24/42 probands (57%), with 18/24 (75%) probands having definitive diagnoses as defined by laboratory and clinical criteria and 6/24 (25%) probands having strong candidate genes. Gene identified in cohort patients most commonly encoded components of the primary cilium, connective tissue, and extracellular matrix. A novel association between KIF7 and USP9X variants and thoracic insufficiency was identified. We report and expand the genetic and phenotypic spectrum of a cohort of children with thoracic insufficiency, reinforce the prevalence of extra-skeletal manifestations in thoracic insufficiency syndromes, and expand the phenotype of KIF7 and USP9X-related disease to include thoracic insufficiency.

Meier-Gorlin Syndrome: Clinical Misdiagnosis, Genetic Testing and Functional Analysis of ORC6 Mutations and the Development of a Prenatal Test

Meier−Gorlin syndrome (MGS) is a rare genetic developmental disorder that causes primordial proportional dwarfism, microtia, the absence of or hypoplastic patellae and other skeletal anomalies. Skeletal symptoms overlapping with other syndromes make MGS difficult to diagnose clinically. We describe a 3-year-old boy with short stature, recurrent respiratory infections, short-rib dysplasia, tower head and facial dysmorphisms who was admitted to the Tomsk Genetic Clinic to verify a clinical diagnosis of Jeune syndrome. Clinical exome sequencing revealed two variants (compound heterozygosity) in the ORC6 gene: c.2T>C(p.Met1Thr) and c.449+5G>A. In silico analysis showed the pathogenicity of these two mutations and predicted a decrease in donor splicing site strength for c.449+5G>A. An in vitro minigene assay indicated that variant c.449+5G>A causes complete skipping of exon 4 in the ORC6 gene. The parents requested urgent prenatal testing for MGS for the next pregnancy, but it ended in a miscarriage. Our results may help prevent MGS misdiagnosis in the future. We also performed in silico and functional analyses of ORC6 mutations and developed a restriction fragment length polymorphism and haplotype-based short-tandem-repeat assay for prenatal genetic testing for MGS. These findings should elucidate MGS etiology and improve the quality of genetic counselling for affected families.

Prenatal Diagnosis of Jeune Syndrome Caused by Compound Heterozygous Variants in DYNC2H1 Gene-Case Report with Rapid WES Procedure and Differential Diagnosis of Lethal Skeletal Dysplasias

Skeletal dysplasias (SDs) are a large, heterogeneous group of mostly genetic disorders that affect the bones and cartilage, resulting in abnormal growth and development of skeletal structures. The high clinical and genetic diversity in SDs cause difficulties in prenatal diagnosis. To establish a correct prognosis and better management, it is very important to distinguish SDs with poor life-limiting prognosis or lethal SDs from other ones. Bad prognosis in foetuses is assessed on the basis of the size of the thorax, lung volumes, long bones’ length, bones’ echogenicity, bones’ angulation or presented fractures, and the concomitant presence of non-immune hydrops or visceral abnormalities. To confirm SD diagnosis and perform family genetic consultation, rapid molecular diagnostics are needed; therefore, the NGS method using a panel of genes corresponding to SD or whole-exome sequencing (WES) is commonly used. We report a case of a foetus showing long bones’ shortening and a narrow chest with short ribs, diagnosed prenatally with asphyxiating thoracic dystrophy, also known as Jeune syndrome (ATD; OMIM 208500), caused by compound heterozygous variants in the DYNC2H1 gene, identified by prenatally performed rapid-WES analysis. The missense variants in the DYNC2H1 gene were inherited from the mother (c.7289T>C; p.Ile2430Thr) and from the father (c.12716T>G; p.Leu4239Arg). The DYNC2H1 gene is one of at least 17 ATD-associated genes. This disorder belongs to the ninth group of SD, ciliopathies with major skeletal involvement. An extremely narrow, bell-shaped chest, and abnormalities of the kidneys, liver, and retinas were observed in most cases of ATD. Next to lethal and severe forms, clinically mild forms have also been reported. A diagnosis of ATD is important to establish the prognosis and management for the patient, as well as the recurrence risk for the family.

Genetic Etiologies, Diagnosis, and Management of Neonatal Cystic Kidney Disease

Fetal kidney development is a complex and carefully orchestrated process. The proper formation of kidney tissue involves many transcription factors and signaling pathways. Pathogenic variants in the genes that encodethese factors and proteins can result in neonatal cystic kidney disease. Advancements in genomic sequencing have allowed us to identify many of these variants and better understand the genetic underpinnings for an increasing number of presentations of childhood kidney disorders. This review discusses the genes essential in kidney development, particularly those involved in the structure and function of primary cilia, and implications of gene identification for prognostication and management of cystic kidney disorders.

A curious case of asphyxiating thoracic dystrophy in an adult

Asphyxiating thoracic dystrophy (ATD), also known as Jeune syndrome, is a rare autosomal recessive chondrodysplasia that most commonly manifests as shortening of long bones and ribs, as well as frequent extra-skeletal organ involvement. It is typically diagnosed in infancy or early childhood following episodes of respiratory distress or failure, in conjunction with characteristic physical findings, and is often fatal. The genetic heterogeneity of this disease, however, means there is varying severity of symptoms and physical manifestations. In this report, we describe a 57-year-old man with his first presentation of respiratory failure, with a history and physical findings consistent with ATD, a diagnosis previously unknown to the patient.

Nephronophthisis-Pathobiology and Molecular Pathogenesis of a Rare Kidney Genetic Disease

The exponential rise in our understanding of the aetiology and pathophysiology of genetic cystic kidney diseases can be attributed to the identification of cystogenic genes over the last three decades. The foundation of this was laid by positional cloning strategies which gradually shifted towards next-generation sequencing (NGS) based screenings. This shift has enabled the discovery of novel cystogenic genes at an accelerated pace unlike ever before and, most notably, the past decade has seen the largest increase in identification of the genes which cause nephronophthisis (NPHP). NPHP is a monogenic autosomal recessive cystic kidney disease caused by mutations in a diverse clade of over 26 identified genes and is the most common genetic cause of renal failure in children. NPHP gene types present with some common pathophysiological features alongside a diverse range of extra-renal phenotypes associated with specific syndromic presentations. This review provides a timely update on our knowledge of this disease, including epidemiology, pathophysiology, anatomical and molecular features. We delve into the diversity of the NPHP causing genes and discuss known molecular mechanisms and biochemical pathways that may have possible points of intersection with polycystic kidney disease (the most studied renal cystic pathology). We delineate the pathologies arising from extra-renal complications and co-morbidities and their impact on quality of life. Finally, we discuss the current diagnostic and therapeutic modalities available for disease management, outlining possible avenues of research to improve the prognosis for NPHP patients.

Cell-based assay for ciliopathy patients to improve accurate diagnosis using ALPACA

Skeletal ciliopathies are a group of disorders caused by dysfunction of the cilium, a small signaling organelle present on nearly every vertebrate cell. This group of disorders is marked by genetic and clinical heterogeneity, which complicates accurate diagnosis. In this study, we developed a robust, standardized immunofluorescence approach to accurately diagnose a subset of these disorders. Hereto we determined and compared the cilium phenotype of healthy individuals to patients from three different ciliopathy subgroups, using skin-derived fibroblasts. The cilium phenotype assay consists of three parameters; (1) ciliogenesis, based on the presence or absence of cilium markers, (2) cilium length, measured by the combined signal of an axonemal and a cilium membrane marker, and (3) retrograde intraflagellar transport (IFT), quantified by the area of the ciliary tip. Analysis of the cilium phenotypic data yielded comparable and reproducible results and in addition, displayed identifiable clusters for healthy individuals and two ciliopathy subgroups, i.e. ATD and CED. Our results illustrate that standardized analysis of the cilium phenotype can be used to discriminate between ciliopathy subgroups. Therefore, we believe that standardization of functional assays analyzing cilium phenotypic data can provide additional proof for conclusive diagnosis of ciliopathies, which is essential for routine diagnostic care.

A new technique for neonatal Jeune syndrome: External thoracic expansion

Jeune syndrome is a rare form of skeletal dysplasia characterized by a narrow, bell-shaped chest (thoracic cage), and typical phalangeal and pelvic bone deformities. Chest expansion is impaired by the short, horizontally positioned ribs, resulting in alveolar hypoventilation and eventually neonatal-infantile death in most cases. External distraction with sternoplasty is a new technique for the treatment of Jeune syndrome, which was firstly used by our team on a newborn by placing a sliding finger fixator which was designed for ulnar lengthening. We believe that this approach can be life-saving in neonates with improved and widespread usage.

Overlapping holoprosencephaly-polydactyl syndrome and asphyxiating thoracic dystrophy, an incidental finding in late prenatal ultrasound: A rare case report

Holoprosencephaly-polydactyly syndrome and asphyxiating thoracic dystrophy rarely overlap but if they do, they have poorer prognosis. Early prenatal detection of multiple congenital anomalies plays a crucial role in the management of pregnancy.

Biallelic loss of function variant in the unfolded protein response gene PDIA6 is associated with asphyxiating thoracic dystrophy and neonatal-onset diabetes

Protein disulfide isomerase A6 (PDIA6) is an unfolded protein response (UPR)-regulating protein. PDIA6 regulates the UPR sensing proteins, Inositol requiring enzyme 1, and EIF2AK3. Biallelic inactivation of the two genes in mice and humans resulted in embryonic lethality, diabetes, skeletal defects, and renal insufficiency. We recently showed that PDIA6 inactivation in mice caused embryonic and early lethality, diabetes and immunodeficiency. Here, we present a case with asphyxiating thoracic dystrophy (ATD) syndrome and infantile-onset diabetes. Whole exome sequencing revealed a homozygous frameshift variant in the PDIA6 gene. RNA expression was reduced in a gene dosage-dependent manner, supporting a loss-of-function effect of this variant. Phenotypic correlation with the mouse model recapitulated the growth defect and delay, early lethality, coagulation, diabetes, immunological, and polycystic kidney disease phenotypes. In general, the phenotype of the current patient is consistent with phenotypes associated with the disruption of PDIA6 and the sensors of UPR in mice and humans. This is the first study to associate ATD to the UPR gene, PDIA6. We recommend screening ATD cases with or without insulin-dependent diabetes for variants in PDIA6.

First Report of Spinal Anesthesia for Cesarean Delivery in a Parturient With Jeune Syndrome: A Case Report

Jeune syndrome, also known as asphyxiating thoracic dystrophy, is a rare form of autosomal recessive skeletal dysplasia. Respiratory distress due to thoracic and lung dysplasia is the primary complication associated with this disorder in neonates. Women with Jeune syndrome seldom conceive and give birth, as only a few survive until adulthood. Herein, we report the world's first case of a cesarean delivery under spinal anesthesia in a pregnant woman with Jeune syndrome with a history of chest wall reconstruction and spinal fusion surgeries.

Thirteen Years' Progression of Macular Atrophy in a Patient With Jeune Syndrome

Jeune syndrome is a rare skeletal dysplasia with an associated retinal dystrophy. The authors describe a case of progressive bilateral macular atrophy (with multimodal imaging) in a patient with Jeune syndrome who was followed over 13 years. This case, confirmed with genetic testing, highlights the importance of characterizing the relationship between phenotype and genotype in this genetically heterogenous condition. [Ophthalmic Surg Lasers Imaging Retina. 2021;52:107-109.].

Novel IFT140 variants cause spermatogenic dysfunction in humans

BACKGROUND

The intraflagellar transport protein 140 homolog (IFT140) is involved in the process of intraflagellar transport (IFT), a process that is essential for the formation and maintenance of most eukaryotic cilia and flagella. Variants IFT140 have been reported to account for ciliopathy but association with male fertility has never been described in humans. Here we report the identification of two novel variants of IFT140 which caused spermatogenic dysfunction and male infertility.

METHODS

Whole-exome sequencing was performed in a 27-year-old infertile man presented with severe oligozoospermia, asthenozoospermia, and teratozoospermia (OAT) without other physical abnormality. Sanger sequencing was used to verify gene variants in the patient, his healthy brother, and their parents. Morphology and protein expression in the patient's sperm were examined by transmission electron microscopy (TEM) and immunofluorescence staining. Function of gene variants was predicted by online databases.

RESULTS

Compound heterozygous variants of IFT140: exon16: c.1837G > A: p.Asp613Asn and exon31: c.4247G > A: p.Ser1416Asn were identified in the patient, both of which showed autosomal recessive inheritance in his family, and had extremely low allele frequency in the population. Morphological abnormalities of the head, nucleus, and tails and the absence of IFT140 from the neck and mid-piece of the patient's spermatozoa were observed. Mutation Taster database predicted a high probability of damage-causing by both variations.

CONCLUSION

This study for the first time reported IFT140 variants that cause infertility in humans.

Congenital hepatic fibrosis and coexistent retinal macular degeneration: A case report

RATIONALE

Congenital hepatic fibrosis (CHF) is an autosomal recessive disease characterized by periportal fibrosis, portal hypertension, and renal cystic disease. Essentially, CHF is a variant of fibrocystic disorder in which liver and kidney are commonly affected. Other frequently associated conditions include Caroli syndrome and polycystic kidney disease. CHF is also a known accompaniment in an array of inherited disorders with multiorgan involvement.

PATIENT CONCERNS

The 20-year-old male patient with declining vision (14 years duration), intermittent gingival bleeding (7 years duration), and abdominal distension (5 years duration), presented with exacerbation of these symptoms during the prior 2 months. The patient had been previously diagnosed with retinal macular degeneration, idiopathic thrombocytopenic purpura, and hepatosplenomegaly.

DIAGNOSES

Liver biopsy showed disordered hepatic acini and fibrous parenchymal banding, indicative of CHF.

INTERVENTIONS

After the treatment of diuresis and liver protectants, the clinical symptoms of the patients were improved. We subsequently recommend chromosomal analysis, although the family refused.

OUTCOMES

Three months after discharge, the patient was followed up by telephone. The patient had obvious abdominal distension and we advised that he should be admitted again. But the family refused.

LESSONS

CHF is an AR disease resulting in portal hypertension and often associated with renal malformations. CHF is also linked to a number of other disorders, many of which are ciliopathies. Because the clinical manifestations of CHF are nonspecific or lacking, its diagnosis is problematic, relying largely on liver biopsy. Once CHF is identified, physicians are obligated to investigate other organ systems, particularly a search for neuromuscular, retina or renal involvement. This case underscores the value of radiologic imaging, pathologic examination, and genetic testing in successfully diagnosing a rare disease.

An unusual case of hypercapnic respiratory failure

Asphyxiating thoracic dystrophy (ATD also known as Jeune syndrome) is a very rare disorder with an incidence in the United States of 1 case per 100,000-130,000 live births. Chronic alveolar hypoventilation leading to concurrent hypoxia is the main cause of morbidity and mortality in these patients due to its complications. A 22-year-old male with past medical history of ATD and severe kyphoscoliosis presented with progressively worsening shortness of breath for several days. Past surgical history was significant for multiple reconstructive sternal surgeries, his first surgery was at the age of two. His chest exam was without wheezing and was notable for symmetrically decreased breath sounds. Arterial blood gas showed PH 7.17, PCO2 155, PO2 95 and O2 saturation of 97% on 2 L nasal cannulae. PA and lateral chest xrays showed a long and severely narrow thoracic cavity. 2D echocardiography showed left ventricular ejection fraction of 55% and evidence of severe pulmonary hypertension. CT chest angiography showed severe dilatation of the pulmonary artery in comparison to ascending aorta and significant right ventricular enlargement. Right heart catheterization confirmed these findings with a mean pulmonary arterial pressure of 61 mmHg. Within several days of hospitalization, patient developed acute worsening of his chronic hypercapnic respiratory failure thought to be due to worsening of pulmonary arterial hypertension with right heart failure. This in return was attributed to underlying ventilatory failure secondary to severe thoracic dystrophy. ATD is an autosomal recessive genetic disorder. Mutations in the IFT80 gene, which encode for an intraflagellar protein, cause this protein to be defective. Clinically, ATD is characterized by a small, narrow chest and variable limb shortness. While ATD is compatible with life, respiratory failure and infections are often fatal during infancy. Patients that survive past the age of 2 have seen respiratory complications resolve due to less pronounced thoracic malformations, but in our case the main cause of worsening pulmonary function was the degree of pulmonary arterial hypertension and right heart failure. Patients with ATD usually develop progressive hypercapnic respiratory failure due to an abnormally small thorax. Surgical options include lateral thoracic expansion or sternal and chest wall reconstruction. However, these surgeries only add a few years to survival without a definitive cure.

Anesthetic management of a child with Kagami-Ogata syndrome complicated with marked tracheal deviation: a case report

Background

Kagami-Ogata syndrome (KOS) is a rare congenital imprinting disorder. The problems related to the anesthetic management of patients with KOS are respiratory distress and difficult endotracheal intubation.

Case presentation

A 2-year-old male was scheduled to undergo orchiopexy for bilateral cryptorchidism. Although he had a history of severe respiratory distress immediately after birth, his preoperative respiratory condition was stable. He also had marked tracheal deviation. General anesthesia was induced with nitrous oxide and sevoflurane in oxygen. A laryngeal mask airway (LMA) was inserted following rocuronium administration. Anesthesia was maintained with sevoflurane and simultaneous caudal anesthesia. His postoperative course was uneventful.

Conclusions

Patients with KOS should preferably undergo elective surgery only after infancy because their respiratory status is more stable as they grow older. Thorough preoperative evaluation of the respiratory tract is important even in KOS patients with a stable respiratory condition.

Primary presentation of Jeune's syndrome as gastric motility disorder in an infant: A case report

We report a case of a 4-week-old female neonate with Jeune's asphyxiating thoracic dystrophy (JATD) and coexistent situs anomaly, primarily presenting as gastric motility disorder. The child presented with abdominal distension and nonbilious vomiting since birth with failure to thrive. However, skeletal survey revealed JATD. Upper gastrointestinal contrast study showed situs inversus with delayed gastric emptying. Pyloric biopsy and intraoperative antro-duodenal manometry confirmed association of gastric motility disorder. Awareness of the unusual possibility of primary presentation of Jeune syndrome as gastric motility disorder will improve the management approach in such infants.

Zebrafish as a Model for Drug Screening in Genetic Kidney Diseases

Genetic disorders account for a wide range of renal diseases emerging during childhood and adolescence. Due to the utilization of modern biochemical and biomedical techniques, the number of identified disease-associated genes is increasing rapidly. Modeling of congenital human disease in animals is key to our understanding of the biological mechanism underlying pathological processes and thus developing novel potential treatment options. The zebrafish (Danio rerio) has been established as a versatile small vertebrate organism that is widely used for studying human inherited diseases. Genetic accessibility in combination with elegant experimental methods in zebrafish permit modeling of human genetic diseases and dissecting the perturbation of underlying cellular networks and physiological processes. Beyond its utility for genetic analysis and pathophysiological and mechanistic studies, zebrafish embryos, and larvae are amenable for phenotypic screening approaches employing high-content and high-throughput experiments using automated microscopy. This includes large-scale chemical screening experiments using genetic models for searching for disease-modulating compounds. Phenotype-based approaches of drug discovery have been successfully performed in diverse zebrafish-based screening applications with various phenotypic readouts. As a result, these can lead to the identification of candidate substances that are further examined in preclinical and clinical trials. In this review, we discuss zebrafish models for inherited kidney disease as well as requirements and considerations for the technical realization of drug screening experiments in zebrafish.

Management of Congenital Heart Disease Associated with Ellis-van Creveld Short-rib Thoracic Dysplasia

OBJECTIVE

To evaluate clinical outcome of patients with Ellis-van Creveld syndrome (EVC) in whom congenital heart disease (CHD) repair was delayed intentionally to reduce the risk of postoperative respiratory morbidity and mortality.

STUDY DESIGN

This retrospective review of 51 EVC c.1886+5G>T homozygotes born between 2005 and 2014 focused on 18 subjects who underwent surgery for CHD, subdivided into early (mean, 1.3 months) vs delayed (mean, 50.1 months) repair.

RESULTS

Growth trajectories differed between control subjects and patients with EVC, and CHD was associated with slower weight gain. Relative to controls, infants with EVC had a 40%-75% higher respiratory rates (independent of CHD) accompanied by signs of compensated respiratory acidosis. Blood gases and respiratory rates approached normal values by age 4 years. Hemodynamically significant CHD was present in 23 children, 18 (78%) of whom underwent surgical repair. Surgery was performed at 1.3 ± 1.3 months for children born between 2005 and 2009 (n = 9) and 50.1 ± 40.2 months (P = .009) for children born between 2010 and 2014 (n = 9). The latter had shorter postoperative mechanical ventilation (1.1 ± 2.4 days vs 49.6 ± 57.1 days; P = .075), shorter intensive care duration of stay (16 ± 24 days vs 48.6 ± 44.2 days; P = .155), and no postoperative tracheostomies (vs 60%; P = .028) or deaths (vs 44%; P = .082).

CONCLUSION

Among children with EVC and possibly other short-rib thoracic dysplasias, delayed surgical repair of CHD reduces postoperative morbidity and improves survival. Respiratory rate serves as a simple indicator for optimal timing of surgical repair.

Is Asphyxiating Thoracic Dystrophy (Jeune's Syndrome) Deadly and Should We Insist on Treating It? Reconstructive Surgery "On Demand"

Our aim is to present the treatment of one of the skeletal manifestations of Jeune's syndrome (JS), the hypoplastic chest, which can result in thoracic insufficiency syndrome and present "on-demand" stage surgical technique using mandible locking plate system for the fixation of ribs. The diagnosis "Jeune's syndrome" was presented clinically in a 3-month-old girl from a family in which the first child died of JS at the age of 18 months. After close follow-up for several months and preoperative planning, we decided to make reconstructive chest operation with atypical use of a double-angled mandible locking plate for fixation. The plate was shaped as a "crown" to ensure the three dimension stability, from the dorsal part of the most curved ribs (paravertebrally) to the sternum after the resection of this area. Operation was done at the period of worsened breathing. For nearly 1 year, the rib cage preserved its stability and the child was in good condition. During the next 3 months, the upper part of the deformation started to grow inward fast. Second operation was "on demand," and the implants used were mandible locking plates curved anterolaterally to effectuate extension of the rib cage and the sternum. In both the reconstructive operations, we spared the rectus and pectoral muscles and achieved good enlargement of the thoracic volume. The postoperative period is smooth and the child is active, without complications. We believe that in the future, the treatment should be "on demand" according to the course of the illness and the results of the follow-up examinations and adequate to the progress of chest wall deformity.

Mutations in IFT-A satellite core component genes IFT43 and IFT121 produce short rib polydactyly syndrome with distinctive campomelia

Background

Skeletal ciliopathies comprise a spectrum of ciliary malfunction disorders that have a profound effect on the skeleton. Most common among these disorders is short rib polydactyly syndrome (SRPS), a recessively inherited perinatal lethal condition characterized by a long narrow chest, markedly shortened long bones, polydactyly and, often, multi-organ system involvement. SRPS shows extensive locus heterogeneity with mutations in genes encoding proteins that participate in cilia formation and/or function.

Results

Herein we describe mutations in IFT43, a satellite member of the retrograde IFT-A complex, that produce a form of SRPS with unusual bending of the ribs and appendicular bones. These newly described IFT43 mutations disrupted cilia formation, produced abnormalities in cartilage growth plate architecture thus contributing to altered endochondral ossification. We further show that the IFT43 SRPS phenotype is similar to SRPS resulting from mutations in the gene encoding IFT121 (WDR35), a direct interactor with IFT43.

Conclusions

This study defines a new IFT43-associated phenotype, identifying an additional locus for SRPS. The data demonstrate that IFT43 is essential for ciliogenesis and that the mutations disrupted the orderly proliferation and differentiation of growth plate chondrocytes, resulting in a severe effect on endochondral ossification and mineralization. Phenotypic similarities with SRPS cases resulting from mutations in the gene encoding the IFT43 direct interacting protein IFT121 suggests that similar mechanisms may be disrupted by defects in these two IFT-A satellite interactors.

Electronic supplementary material

The online version of this article (doi:10.1186/s13630-017-0051-y) contains supplementary material, which is available to authorized users.

Anesthetic Management of a Child With Jeune Syndrome for Tracheotomy: A Case Report

Jeune syndrome is a rare autosomal-recessive skeletal disorder. Anesthetic management of these patients is often difficult because of thoracic and lung hypoplasia. A 5-month-old boy with Jeune syndrome was scheduled to undergo a tracheotomy. Despite 5-minute preoxygenation with continuous positive airway pressure, the patient's oxygen saturation rapidly dropped during the induction of anesthesia. The continuous positive airway pressure should have been titrated to effective tidal volume during preoxygenation to recruit the patient's functional residual capacity and to prevent desaturation. During tracheotomy, volume-controlled ventilation with a high respiratory rate and sufficient inspiratory time effectively improved the patient's respiratory status.

[Infant respiratory distress revealing Jeune syndrome]

Jeune syndrome (asphyxiating thoracic dystrophy) is a rare autosomal recessive osteochondrodysplasia with a variable degree of severity, clinically characterized by respiratory distress with a narrow chest and limb shortness. The reported incidence is one to five in 500,000 live births. Most patients develop severe respiratory failure during the first 2 years of life, leading to death in 60-80 % of cases. Survivors may suffer from renal, hepatic, or pancreatic complications. Expanding thoracic surgery can be used for severe cases. We describe the case of an 18-month-old boy who developed mild respiratory distress. The patient showed typical radiological features of Jeune syndrome: narrow thorax with short ribs and trident appearance of the pelvis. This case underscores the value of the right interpretation of the chest radiograph of the infant with a respiratory distress syndrome.

Effective Neurally Adjusted Ventilatory Assist (NAVA) Ventilation in a Child With Jeune Syndrome

Jeune syndrome (asphyxiating thoracic dystrophy) is a rare skeletal dysplasia mainly characterized by dystrophy of the thoracic cage. Neurally adjusted ventilatory assist (NAVA) is a respiratory support in which pressure assistance is provided in proportion to and synchronous with the electrical activity of the diaphragm. We present the case of a 4-month-old infant with asphyxiating thoracic dystrophy and respiratory failure successfully ventilated with NAVA. In this case, NAVA improved patient-ventilator synchrony, reducing endotracheal secretion and gastric overdistention. The reduction of breathing effort and the improvement in enteral feeding tolerance and weight gain made the patient eligible for thoracic surgical correction.

Spinal correction of scoliosis in Jeune syndrome: a report of two cases

Background

Jeune syndrome (asphyxiating thoracic dystrophy) is an autosomal recessive disorder with constriction and narrowing of the thorax. To our knowledge, there are no reports regarding spinal deformity and correction in Jeune syndrome. Herein, we report two cases of spinal correction in patients with Jeune syndrome, and review the literature.

Case Presentation

We experienced cases of spinal scoliosis in an adolescent boy and a young adult woman, both with Jeune syndrome. Their spinal deformities had progressed by the time they came to our hospital for surgical correction. After preoperative evaluation of their general condition, including respiratory function in detail to confirm that they could undergo surgery, we treated both cases with posterior spinal correction and fusion. Spinal correction was performed safely and there were no severe complications, including respiratory depression, associated with surgery, and relatively satisfactory correction was obtained in both cases. In case 1, coronal deformity was corrected from 70° to 36° and from 82° to 42°, respectively. In case 2, Cobb angle was corrected from 52° to 20° and from 55° to 21°.

Conclusions

Posterior spinal correction can be performed safely in young patients with Jeune syndrome who have survived their infant stage and matured without a severe general condition.

The Radiograph of the Pelvis as a Window to Skeletal Dysplasias

Skeletal dysplasias are disorders of bone formation. There are many dysplasias that have been identified and studied over the years and long lists of radiological features have been documented; it is not possible to remember all of them, most of which are common to more than one dysplasia. This article is about a practical approach to the radiological diagnosis of skeletal dysplasias by viewing only a few radiographs rather than the entire skeletal survey. The radiographs that are to be studied are AP view of the pelvis, dorsolumbar spine- AP and lateral view and both hands PA view, in that order. The skull lateral view and both knees AP view are sometimes required. The authors advice to set out with the pelvis that provides information of not only the pelvic bones but also parts of the lumbar spine and the upper ends of the femur including their epiphyses, metaphyses and a part of the diaphyses. Sometimes the diagnosis is reached with only this one radiograph, as in achondroplasia or it may indicate a group like mucopolysaccharidoses which can be sorted out with radiographs of the spine and hands or the upper part of the femur can provide a cue to epiphyseal and metaphyseal dysplasias. Gamuts and atlases can be consulted for the rare dysplasias.

Distraction osteogenesis of the sternum for thoracic expansion in a severe case of jeune syndrome: a preliminary report

Severe asphyxiating thoracic dystrophy (Jeune syndrome) is usually fatal. The authors used distraction osteogenesis in a severe case and achieved 45 mm distraction of the sternum and improvement in tidal volume, lung compliance, and mean airway pressure.

Management of Thoracic Insufficiency Syndrome in Patients With Jeune Syndrome Using the 70 mm Radius Vertical Expandable Prosthetic Titanium Rib

BACKGROUND

Jeune syndrome (JS) often results in lethal thoracic insufficiency syndrome. Since 1991, vertical expandable prosthetic titanium rib Dynamic PosteroLateral Expansion Thoracoplasty was used at our institution for treatment of JS. This study assesses the safety and efficacy of this procedure.

METHODS

Twenty-four JS patients were treated, 2 lost to follow-up, 17 with a minimum of 2-year follow-up retrospectively reviewed for clinical course: Assisted Ventilation Rate, respiratory rate, capillary blood gases, pulmonary function testings, and complications. Upright anteroposterior/lateral radiographs were measured for Cobb angle, kyphosis, lordosis, thoracic width, and thoracic/lumbar spinal height. Computed tomography scan lung volumes were obtained in 12 patients.

RESULTS

Mean age at initial implant was 23 months (7 to 62 mo) with an average 8.4 years (2.3 to 15.6 y) of follow-up. Average chest width increased from 121 to 168 mm at follow-up (P<0.001). Preoperatively, 7/17 (41%) patients had scoliosis. The remainder developed scoliosis during treatment, 8 requiring additional implants. Thoracic and lumbar spinal height was normal preoperatively and stayed normal during treatment. Thoracic kyphosis/lumbar lordosis was stable. Average computed tomography scan total lung volumes increased 484 to 740 mm3 (P<0.001), and Assisted Ventilation Rate status tended to improve (P=0.07). Average forced vital capacity was 34% predicted at first test and 27% predicted at last follow-up. Early demise after surgery was common with multisystem disease. Mean respiratory rate decreased from 35 to 24 bpm at last follow-up (P<0.05). Survival rate of the 22 patients was 68%. Migration of the rib cradles/titanium slings occurred in 12 patients, superficial infections in 5 patients, deep infections in 4 patients, and wound dehiscence in 5 patients. Infection rate was 4.6% per procedure.

CONCLUSIONS

The survival rate in JS with surgery was nearly 70% (compared with 70% to 80% mortality without treatment) with less ventilator dependence. Both C1 stenosis and scoliosis are common in JS. Spinal height in JS is normal. Complications are frequent, but tolerable in view of the clinical gains and increase in survival.

Mutations in human IFT140 cause non-syndromic retinal degeneration

Leber congenital amaurosis (LCA) and retinitis pigmentosa (RP) are two genetically heterogeneous retinal degenerative disorders. Despite the identification of a number of genes involved in LCA and RP, the genetic etiology remains unknown in many patients. In this study, we aimed to identify novel disease-causing genes of LCA and RP. Retinal capture sequencing was initially performed to screen mutations in known disease-causing genes in different cohorts of LCA and RP patients. For patients with negative results, we performed whole exome sequencing and applied a series of variant filtering strategies. Sanger sequencing was done to validate candidate causative IFT140 variants. Exome sequencing data analysis led to the identification of IFT140 variants in multiple unrelated non-syndromic LCA and RP cases. All the variants are extremely rare and predicted to be damaging. All the variants passed Sanger validation and segregation tests provided that the family members' DNA was available. The results expand the phenotype spectrum of IFT140 mutations to non-syndromic retinal degeneration, thus extending our understanding of intraflagellar transport and primary cilia biology in the retina. This work also improves the molecular diagnosis of retinal degenerative disease.

Anesthetic Approach for a Patient with Jeune Syndrome

Jeune syndrome (JS) is an autosomal recessive disease also known as asphyxiating thoracic dystrophy. A narrow bell-shaped thoracic wall and short extremities are the most typical features of the syndrome. Prognosis in JS depends on the severity of the pulmonary hypoplasia caused by the chest wall deformity. Most patient deaths are due to respiratory problems at early ages. Herein, we report a case of JS patient, who was scheduled for femoral extension under general anesthesia. The severity of respiratory problems in JS patients is thought to diminish with age. Our case supported this theory, and we managed the anesthetic process uneventfully.

Chest wall hypoplasia--principles and treatment

The chest is a dynamic structure. For normal movement it relies on a coordinated movement of the multiple bones, joints and muscles of the respiratory system. While muscle weakness can have clear impact on respiration by decreasing respiratory motion, so can conditions that cause chest wall hypoplasia and produce an immobile chest wall. These conditions, such as Jarcho-Levin and Jeune syndrome, present significantly different challenges than those faced with early onset scoliosis in which chest wall mechanics and thoracic volume may be much closer to normal. Because of this difference more aggressive approaches to clinical and surgical management are necessary.

Cilia/Ift protein and motor -related bone diseases and mouse models

Primary cilia are essential cellular organelles projecting from the cell surface to sense and transduce developmental signaling. They are tiny but have complicated structures containing microtubule (MT)-based internal structures (the axoneme) and mother centriole formed basal body. Intraflagellar transport (Ift) operated by Ift proteins and motors are indispensable for cilia formation and function. Mutations in Ift proteins or Ift motors cause various human diseases, some of which have severe bone defects. Over the last few decades, major advances have occurred in understanding the roles of these proteins and cilia in bone development and remodeling by examining cilia/Ift protein-related human diseases and establishing mouse transgenic models. In this review, we describe current advances in the understanding of the cilia/Ift structure and function. We further summarize cilia/Ift-related human diseases and current mouse models with an emphasis on bone-related phenotypes, cilia morphology, and signaling pathways.

Primary thoraco-spinal disorders of childhood

Primary structural deformities of the spine and thorax were at one time rare and reportable in case series. With the development of new "growth friendly" implantable devices, children with these disorders are living longer and receiving both surgical and pulmonary care. As a result, there has been growing interest in the functional cardiopulmonary consequences of these deformities, the current surgical and non-surgical treatments, and the role of long-term supportive care. This article reviews current literature in this rapidly changing field, where new devices are developed and outcomes are changing. The respiratory consequences of early-onset thoraco-spinal disorders are emphasized and the roles of the pulmonologist and surgeons are discussed. There are more questions than answers as no long-term outcome data yet exists.

A case of neonatal Jeune syndrome expanding the phenotype

Key Clinical Message

We report the case of a premature, very low birth weight, newborn with stigmata of Jeune syndrome, a rare skeletal dysplasia, and marked renal involvement (i.e. remarkable prenatal oligohydramnios, histologic nephronophthisis-like pattern, macroscopic renal cysts, and renal failure), expanding the phenotype consistent with the continuum of syndromic ciliopathies.

Loss of cilia causes embryonic lung hypoplasia, liver fibrosis, and cholestasis in the talpid3 ciliopathy mutant

Sonic hedgehog plays an essential role in maintaining hepatoblasts in a proliferative non-differentiating state during embryogenesis. Transduction of the Hedgehog signaling pathway is dependent on the presence of functional primary cilia and hepatoblasts, therefore, must require primary cilia for normal function. In congenital syndromes in which cilia are absent or non-functional (ciliopathies) hepatorenal fibrocystic disease is common and primarily characterized by ductal plate malformations which underlie the formation of liver cysts, as well as less commonly, by hepatic fibrosis, although a role for abnormal Hedgehog signal transduction has not been implicated in these phenotypes. We have examined liver, lung and rib development in the talpid³ chicken mutant, a ciliopathy model in which abnormal Hedgehog signaling is well characterized. We find that the talpid³ phenotype closely models that of human short-rib polydactyly syndromes which are caused by the loss of cilia, and exhibit hypoplastic lungs and liver failure. Through an analysis of liver and lung development in the talpid³ chicken, we propose that cilia in the liver are essential for the transduction of Hedgehog signaling during hepatic development. The talpid³ chicken represents a useful resource in furthering our understanding of the pathology of ciliopathies beyond the treatment of thoracic insufficiency as well as generating insights into the role Hedgehog signaling in hepatic development.

One-stage sequential bilateral thoracic expansion for asphyxiating thoracic dystrophy (Jeune syndrome)

OBJECTIVES

Jeune syndrome (asphyxiating thoracic dystrophy) is a rare disorder characterized by skeletal dysplasia, reduced diameter of the thoracic cage and extrathoracic organ involvement. Fatal, early respiratory insufficiency may occur. Two-stage lateral thoracic expansion has been reported, addressing each side sequentially over 3-12 months. While staged repair theoretically provides less invasive surgery in a small child with respiratory distress, we utilized a single stage, bilateral procedure aiming to rapidly maximize lung development. Combined bilateral surgery also offered the chance of rapid recovery, and reduced hospital stay. We present our early experience of this modification of existing surgical treatment for an extremely rare condition, thought to be generally fatal in early childhood.

METHODS

Nine children (6 males, 3 females; median age 30 months [3.5-75]) underwent thoracic expansion for Jeune syndrome in our centre. All patients required preoperative respiratory support (5 with tracheostomy, 8 requiring positive pressure ventilation regularly within each day/night cycle). Two children underwent sequential unilateral (2-month interval between stages) and 7 children bilateral thoracic expansion by means of staggered osteotomies of third to eighth ribs and plate fixation of fourth to fifth rib and sixth to seventh rib, leaving the remaining ribs floating.

RESULTS

There was no operative mortality. There were 2 deaths within 3 months of surgery, due to pulmonary hypertension (1 following two-stage and 1 following single-stage thoracic expansion). At the median follow-up of 11 months (1-15), 3 children have been discharged home from their referring unit and 2 have significantly reduced respiratory support. One child remains on non-invasive ventilation and another is still ventilated with a high oxygen requirement.

CONCLUSION

Jeune syndrome is a difficult condition to manage, but bilateral thoracic expansion offers an effective reduction in ventilator requirements in these children. While two-stage repair has been described previously, this is the first report of single-stage bilateral thoracic expansion. Single-stage repair is feasible and may offer better resource management and significant cost savings by potentially reducing theatre usage and overall length of stay (intensive care and hospital) without compromising clinical outcomes.

Development of an automated imaging pipeline for the analysis of the zebrafish larval kidney

The analysis of kidney malformation caused by environmental influences during nephrogenesis or by hereditary nephropathies requires animal models allowing the in vivo observation of developmental processes. The zebrafish has emerged as a useful model system for the analysis of vertebrate organ development and function, and it is suitable for the identification of organotoxic or disease-modulating compounds on a larger scale. However, to fully exploit its potential in high content screening applications, dedicated protocols are required allowing the consistent visualization of inner organs such as the embryonic kidney. To this end, we developed a high content screening compatible pipeline for the automated imaging of standardized views of the developing pronephros in zebrafish larvae. Using a custom designed tool, cavities were generated in agarose coated microtiter plates allowing for accurate positioning and orientation of zebrafish larvae. This enabled the subsequent automated acquisition of stable and consistent dorsal views of pronephric kidneys. The established pipeline was applied in a pilot screen for the analysis of the impact of potentially nephrotoxic drugs on zebrafish pronephros development in the Tg(wt1b:EGFP) transgenic line in which the developing pronephros is highlighted by GFP expression. The consistent image data that was acquired allowed for quantification of gross morphological pronephric phenotypes, revealing concentration dependent effects of several compounds on nephrogenesis. In addition, applicability of the imaging pipeline was further confirmed in a morpholino based model for cilia-associated human genetic disorders associated with different intraflagellar transport genes. The developed tools and pipeline can be used to study various aspects in zebrafish kidney research, and can be readily adapted for the analysis of other organ systems.

Mutations in the gene encoding IFT dynein complex component WDR34 cause Jeune asphyxiating thoracic dystrophy

Bidirectional (anterograde and retrograde) motor-based intraflagellar transport (IFT) governs cargo transport and delivery processes that are essential for primary cilia growth and maintenance and for hedgehog signaling functions. The IFT dynein-2 motor complex that regulates ciliary retrograde protein transport contains a heavy chain dynein ATPase/motor subunit, DYNC2H1, along with other less well functionally defined subunits. Deficiency of IFT proteins, including DYNC2H1, underlies a spectrum of skeletal ciliopathies. Here, by using exome sequencing and a targeted next-generation sequencing panel, we identified a total of 11 mutations in WDR34 in 9 families with the clinical diagnosis of Jeune syndrome (asphyxiating thoracic dystrophy). WDR34 encodes a WD40 repeat-containing protein orthologous to Chlamydomonas FAP133, a dynein intermediate chain associated with the retrograde intraflagellar transport motor. Three-dimensional protein modeling suggests that the identified mutations all affect residues critical for WDR34 protein-protein interactions. We find that WDR34 concentrates around the centrioles and basal bodies in mammalian cells, also showing axonemal staining. WDR34 coimmunoprecipitates with the dynein-1 light chain DYNLL1 in vitro, and mining of proteomics data suggests that WDR34 could represent a previously unrecognized link between the cytoplasmic dynein-1 and IFT dynein-2 motors. Together, these data show that WDR34 is critical for ciliary functions essential to normal development and survival, most probably as a previously unrecognized component of the mammalian dynein-IFT machinery.

Jeune syndrome: considerations for management of asphyxiating thoracic dystrophy

Jeune syndrome (JS), or asphyxiating thoracic dystrophy, is a rare genetic disorder characterized by a small, narrow thorax, with associated shortening of limbs. Children with JS present with variable degrees of respiratory distress, frequently lethal in the neonatal period. Other associated complications include renal, hepatic, gastrointestinal, and retinal dysfunction. Management focuses on stabilization and support of respiratory function. Treatment may be palliative in nature or corrective. In recent years, the advance in surgical treatment of the thoracic hypoplasia in JS offers hope to those families with a child suffering from the syndrome. Even with increased research into treatment of this disorder, prognosis is usually poor. Comorbidities associated with JS lead to serious organ dysfunction in later years. Families who have a child with JS need genetic counseling and education focusing on the seriousness of the disorder, the risks and benefits of treatment, and the lifelong needs of those with JS.