Mitral Valve Regurgitation in Klippel-Feil Syndrome With Related Thoracic Deformity.

Klippel-Feil syndrome, characterized by congenital fusion of any 2 or more cervical vertebrae, is a rare disorder in which skeletal and other organ system-related abnormalities have been reported. This article reports a case of mitral valve regurgitation in a patient with Klippel-Feil syndrome and related thoracic deformity who underwent mitral valvuloplasty. Postoperatively, the mitral valve regurgitation disappeared, and there has been no recurrence for 3 years. This case highlights mitral valvuloplasty via median sternotomy as an excellent treatment for mitral valve regurgitation in a patient with thoracic deformity related to Klippel-Feil syndrome.

Genetic insights into the 'sandwich fusion' subtype of Klippel-Feil syndrome: novel FGFR2 mutations identified by 21 cases of whole-exome sequencing.

BACKGROUND: Klippel-Feil syndrome (KFS) is a rare congenital disorder characterized by the fusion of two or more cervical vertebrae during early prenatal development. This fusion results from a failure of segmentation during the first trimester. Although six genes have previously been associated with KFS, they account for only a small proportion of cases. Among the distinct subtypes of KFS, "sandwich fusion" involving concurrent fusion of C0-1 and C2-3 vertebrae is particularly noteworthy due to its heightened risk for atlantoaxial dislocation. In this study, we aimed to investigate novel candidate mutations in patients with "sandwich fusion." METHODS: We collected and analyzed clinical data from 21 patients diagnosed with "sandwich fusion." Whole-exome sequencing (WES) was performed, followed by rigorous bioinformatics analyses. Our focus was on the six known KFS-related genes (GDF3, GDF6, MEOX1, PAX1, RIPPLY2, and MYO18). Suspicious mutations were subsequently validated through in vitro experiments. RESULTS: Our investigation revealed two novel exonic mutations in the FGFR2 gene, which had not previously been associated with KFS. Notably, the c.1750A > G variant in Exon 13 of FGFR2 was situated within the tyrosine kinase domain of the protein, in close proximity to several established post-translational modification sites. In vitro experiments demonstrated that this certain mutation significantly impacted the function of FGFR2. Furthermore, we identified four heterozygous candidate variants in two genes (PAX1 and MYO18B) in two patients, with three of these variants predicted to have potential clinical significance directly linked to KFS. CONCLUSIONS: This study encompassed the largest cohort of patients with the unique "sandwich fusion" subtype of KFS and employed WES to explore candidate mutations associated with this condition. Our findings unveiled novel variants in PAX1, MYO18B, and FGFR2 as potential risk mutations specific to this subtype of KFS.

Transient binocular vision loss and pain insensitivity in Klippel-Feil syndrome: a case report.

BACKGROUND: Klippel-Feil syndrome is a rare congenital bone disorder characterized by an abnormal fusion of two or more cervical spine vertebrae. Individuals with Klippel-Feil syndrome exhibit diverse clinical manifestations, including skeletal irregularities, visual and hearing impairments, orofacial anomalies, and anomalies in various internal organs, such as the heart, kidneys, genitourinary system, and nervous system. CASE PRESENTATION: This case report describes a 12-year-old Pashtun female patient who presented with acute bilateral visual loss. The patient had Klippel-Feil syndrome, with the typical clinical triad symptoms of Klippel-Feil syndrome, along with Sprengel's deformity. She also exhibited generalized hypoalgesia, which had previously resulted in widespread burn-related injuries. Upon examination, bilateral optic disc swelling was observed, but intracranial pressure was found to be normal. Extensive investigations yielded normal results, except for hypocalcemia and low vitamin D levels, while parathyroid function remained within the normal range. Visual acuity improved following 2 months of calcium and vitamin D supplementation, suggesting that the visual loss and optic nerve swelling were attributed to hypocalcemia. Given the normal parathyroid function, it is possible that hypocalcemia resulted from low vitamin D levels, which can occur after severe burn scarring. Furthermore, the patient received a provisional diagnosis of congenital insensitivity to pain on the basis of the detailed medical history and the findings of severe and widespread loss of the ability to perceive painful stimuli, as well as impaired temperature sensation. However, due to limitations in genetic testing, confirmation of the congenital insensitivity to pain diagnosis could not be obtained. CONCLUSION: This case highlights a rare presentation of transient binocular vision loss and pain insensitivity in a patient with Klippel-Feil syndrome, emphasizing the importance of considering unusual associations in symptom interpretation.

Klippel-Fiel syndrome with rare presentation of bilateral temporomandibular joint osteoarthritis - A case report.

BACKGROUND: Klippel-Fiel syndrome (KFS) is a rare congenital skeletal disorder characterized clinically by presence of a triad of short neck, limited neck mobility (due to fused cervical vertebrae) and low posterior hair line. It was first described by Maurice Klippel and Andre Feil in 1912. Various skeletal and non-skeletal anomalies may be seen in association with KFS. CASE PRESENTATION: This report aims to highlight orofacial manifestations of a 16-year-old male patient with KFS along with a rare presentation of bilateral osteoarthritic changes in the temporomandibular joint. The treatment planning and execution for such a case has also been described. CONCLUSION: Bilateral osteoarthritic changes of temporomandibular joint have been rarely reported in KFS. This report emphasizes that early diagnosis of various associated anomalies and timely intervention through an interdisciplinary approach is very essential in the management of patients with KFS.

Tetraparesis following thoracic spine surgery in a patient with Klippel-Feil syndrome and ABCB4 mutation: a case report.

BACKGROUND: Klippel-Feil syndrome is a rare condition described in 1912 by Maurice Klippel and André Feil. It is defined as a congenital cervical fusion of at least two vertebrae, associated with a classical triad of clinical signs: short neck, low posterior hairline, and limited range of movement. However, Klippel-Feil syndrome manifests with a vast spectrum of phenotypes, ranging from no symptoms to complete triad, with or without other associated malformations. Most commonly, CCF results from sporadic mutations, even though autosomal recessive, autosomal dominant, or even X-linked inheritance can be detected. The ATP-binding cassette subfamily B member 4 is only expressed in the liver and is involved in biliary phospholipid secretion. The clinical spectrum includes various hepatobiliary pathologies, including low phospholipid-associated cholelithiasis, and has never been associated with musculoskeletal anomalies. CASE PRESENTATION: A 55-year-old male Caucasian patient presenting with low phospholipid-associated cholelithiasis syndrome with ATP-binding cassette subfamily B member 4 mutation and liver cirrhosis was referred to our clinic for a liver transplant. A period of 6 months before, the patient underwent a T7-T9 posterior fixation for a T8 osteoporotic fracture. Postoperatively, he was tetraparetic, whereas he was neurologically intact before the operation. At admission to our hospital, he was still tetraparetic and presented with clinical signs of cervical myelopathy. Moreover, he suffered a limitation of cervical range of motion in all directions, short neck, and low posterior hairline. Imaging showed multiple cervical and thoracic vertebral bodies fusion, as well as cervical spine stenosis. Based on the available data, we diagnosed a type 3 Klippel-Feil syndrome according to Samartzis' classification. CONCLUSIONS: The heterogeneity of KFS and the various potential hereditary links that are known indicate that it is important to highlight all potential cases related to known genetic defects. At present, no association between ATP-binding cassette subfamily B member 4 mutation and congenital cervical fusions has been reported. The other important clinical focus of this case is the appearance of spontaneous tetraparesis after thoracic spine surgery. This mechanism remains unclear, but considering different spinal anatomy it might have been due to difficult intubation and patient's positioning during his previous operation.

Klippel-Feil Syndrome Associated with Renal and Cardiac Anomalies in an Infant: A Case Report.

Klippel-Feil syndrome is a rare congenital bone disorder characterised by a triad of short neck, low posterior hairline and limited lateral bending of the neck with an annual incidence of 1 in 40,000 live births. It has remained an obscure term in the medical literature because of its variability in presentation and wide spectrum of anomalies involving multiple organ systems. It is unusual to find a case that has all three classical triad features. Here, we present a case of a 9-month-old infant who manifests not only all three classical triad features associated with Klippel-Feil syndrome but also demonstrates the presence of congenital heart disease, scoliosis, and renal ectopia. An early comprehensive evaluation of a suspected case is essential for diagnosis and counselling which impacts its prognosis, helps minimize social stigma and affords parents the opportunity to consider cosmetic surgery as an option, should they choose to pursue it. Keywords: case reports; congenital; heart diseases; Klippel-Feil syndrome; scoliosis.

A case of ischemic stroke accompanied by multiple arterial dissections associated with Klippel-Feil syndrome.

OBJECTIVES: To describe the case of an ischemic stroke patient with Klippel-Feil syndrome who developed multiple aneurysms and discuss the mechanism of aneurysm development. MATERIALS AND METHODS: A 44-year-old man presented with dizziness, left hemiparesis, and left-sided numbness and was admitted to our department. He developed multiple aneurysms at the bilateral vertebral artery (VA) and bilateral internal carotid artery. RESULTS: We diagnosed the etiology of his brain infarction as an embolic stroke caused by left VA dissection or the large thrombosed aneurysm. Furthermore, we considered that arterial dissection or Hox gene mutation was associated with the development of multiple aneurysms. CONCLUSION: While previous reports have described single aneurysm, this is the first report of multiple aneurysms associated with Klippel-Feil syndrome.

Klippel-Feil Syndrome: Clinical Presentation and Management.

¼: Klippel-Feil syndrome (KFS) is a rare multisystem constellation of findings with congenital cervical fusion as the hallmark. The etiology is not fully understood. ¼: Recent studies have indicated that KFS is more prevalent than previously described. ¼: Hypermobility in the nonfused segments may lead to adjacent segment disease and potential disc herniation and myelopathy after minor trauma. ¼: Most patients with KFS are asymptomatic and can be managed nonoperatively. Surgical treatment is reserved for patients presenting with pain refractory to medical management, instability, myelopathy or radiculopathy, or severe adjacent segment disease. ¼: Patients with craniocervical abnormalities and upper cervical instability should avoid contact sports as they are at increased risk for spinal cord injury after minor trauma.

Klippel-Feil Syndrome: Pathogenesis, Diagnosis, and Management.

Klippel-Feil syndrome (KFS), or congenital fusion of the cervical vertebrae, has been thought to be an extremely rare diagnosis. However, recent literature suggests an increased prevalence, with a high proportion of asymptomatic individuals. Occurring as a sporadic mutation or associated with several genes, the pathogenesis involves failure of cervical somite segmentation and differentiation during embryogenesis. Most commonly, the C2-C3 and C5-C6 levels are involved. KFS is associated with other orthopaedic conditions including Sprengel deformity, congenital scoliosis, and cervical spine abnormalities, as well as several visceral pathologies. There are several classification systems, some based on the anatomic levels of fusion and others on its genetic inheritance. Management of patients with KFS primarily involves observation for asymptomatic individuals. Surgical treatment may be for neurologic complaints, correction of deformity, concomitant spinal anomalies, or for associated conditions and varies significantly. Participation in sports is an important consideration. Recommendations for contact sports or activities depend on both the level and the number of vertebrae involved in the fusion. A multidisciplinary team should be involved in the treatment plan and recommendations for complex presentations.

A novel pathogenic variant in MYO18B associating early-onset muscular hypotonia, and characteristic dysmorphic features, delineation of the phenotypic spectrum of MYO18B-related conditions.

Homozygous loss-of-function variants in MYO18B have been associated with congenital myopathy, facial dysmorphism and Klippel-Feil anomaly. So far, only four patients have been reported. Comprehensive description of new cases that help to highlight recurrent features and to further delineate the phenotypic spectrum are still missing. We present the fifth case of MYO18B-associated disease in a newborn male patient. Trio exome sequencing identified the previously unreported homozygous nonsense variant c.6433C>T, p.(Arg2145*) in MYO18B (NM_032608.5). While most phenotypic features of our patient align with previously reported cases, we describe the prenatal features for the first time. Taking the phenotypic description of our patient into account, we propose that the core phenotype comprises a severe congenital myopathy with feeding difficulties in infancy and characteristic dysmorphic features.

Klippel Feil Syndrome: Clinical Phenotypes Associated With Surgical Treatment.

STUDY DESIGN: Retrospective study. OBJECTIVE: To define distinct Klippel-Feil syndrome (KFS) patient phenotypes that are associated with the need for surgical intervention. SUMMARY OF BACKGROUND DATA: KFS is characterized by the congenital fusion of cervical vertebrae; however, patients often present with a variety of other spinal and extraspinal anomalies suggesting this syndrome encompasses a heterogeneous patient population. Moreover, it remains unclear how the abnormalities seen in KFS correlate to neurological outcomes and the need for surgical intervention. METHODS: Principal component (PC) analysis was performed on 132 KFS patients treated at a large pediatric hospital between 1981 and 2018. Thirty-five variables pertaining to patient/disease-related factors were examined. Significant PCs were included as independent variables in multivariable logistic regression models designed to test associations with three primary outcomes: cervical spine surgery, thoracolumbar/sacral spine surgery, and cranial surgery. RESULTS: Fourteen significant PCs accounting for 70% of the variance were identified. Five components, representing four distinct phenotypes, were significantly associated with surgical intervention. The first group consisted of predominantly subaxial cervical spine fusions, thoracic spine abnormalities and was associated with thoracolumbar/sacral spine surgery. The second group was largely represented by axial cervical spine anomalies and had high association with cervical subluxation and cervical spine surgery. A third group, heavily represented by Chiari malformation, was associated with cranial surgery. Lastly, a fourth group was defined by thoracic vertebral anomalies and associations with sacral agenesis and scoliosis. This phenotype was associated with thoracolumbar/sacral spine surgery. CONCLUSION: This is the first data-driven analysis designed to relate KFS patient phenotypes to surgical intervention and provides important insight that may inform targeted follow-up regimens and surgical decision-making. LEVEL OF EVIDENCE: 3.

Klippel-Feil syndrome: a review of the literature.

Klippel-Feil syndrome is a congenital defect in the formation or segmentation of the cervical spine. A wide spectrum of associated anomalies may be present. This heterogeneity has complicated clarification of the genetic causes and management of patient's with congenital vertebral fusion. In this review, we focussed on clinical heterogeneity; radiographic abnormalities and genetic etiology in Klippel-Feil syndrome. We insist on comprehensive evaluation and delineation of diagnostic and prognostic classes.

Imaging of Thoracic Wall Abnormalities.

Identification of certain abnormalities of the chest wall can be extremely helpful in correctly diagnosing a number of syndromic conditions and systemic diseases. Additionally, chest wall abnormalities may sometimes constitute diagnoses by themselves. In the present pictorial essay, we review a number of such conditions and provide illustrative cases that were retrospectively identified from our clinical imaging database. These include pentalogy of Cantrell, Klippel-Feil syndrome, cleidocranial dysplasia, Poland syndrome, osteopetrosis, neurofibromatosis type 1, Marfan syndrome, Gardner syndrome, systemic sclerosis, relapsing polychondritis, polymyositis/dermatomyositis, ankylosing spondylitis, hyperparathyroidism, rickets, sickle cell anemia, thalassemia, tuberculosis, septic arthritis of the sternoclavicular joint, elastofibroma dorsi, and sternal dehiscence.

Klippel-Feil syndrome misdiagnosed as spondyloarthropathy: case-based review.

Spondyloarthropathy refers to any joint disease of the vertebral column, but the term is mainly used for a specific group of disorders called seronegative spondyloarthropathies (SpAs). The axial skeletal involvement, peripheral and extra-articular manifestations and an association with the major histocompatibility complex class I human leukocyte antigen-B27 (HLA B27) are commonly shared features of SpAs. Klippel-Feil syndrome (KFS) is a rare congenital disorder characterized by the fusion of one or more cervical vertebrae, accompanied by various skeletal and extra-skeletal anomalies. We report a case of an adult male patient with HLA B27 positivity presenting with chronic cervical spine pain accompanied by morning stiffness and periodic night pain, with radiologically confirmed ankylosis and fusion of several cervical segments. His medical history included urogenital abnormalities operated in childhood and mild mitral prolapse. Initially suspected diagnosis of an early axial form of SpA was rejected after thorough workup. Instead, the nature of vertebral defects along with the past medical history of urogenital and cardiac abnormalities pointed towards the diagnosis of KFS. HLA B27 presence can be a confounder in patients presenting with spinal pain and that is why the differential diagnosis of CSD-s and SpA can be challenging in some patients.

Klippel-Feil syndrome: A very unusual cause of severe aortic regurgitation visualized by multimodality imaging.

A 51-year-old man with Klippel-Feil syndrome (KFS) and immunodeficiency syndrome, status postintravenous immunoglobulin therapy, presented with shortness of breath. He was found to have severe aortic regurgitation in the setting of a trileaflet aortic valve with thickened leaflets and mild prolapse of the right coronary cusp with left ventricular dilation and borderline left ventricular ejection fraction. Although various cardiac anomalies have been described in KPS, otherwise unexplained severe aortic regurgitation has not been previously reported to the best of our knowledge. The patient underwent an uncomplicated surgical aortic valve replacement with a 25-mm Medtronic Avalus pericardial tissue valve resulting in symptomatic improvement. Intra-operative management and transesophageal echocardiography can be particularly challenging in KFS patients. We describe the first reported case of severe aortic regurgitation in KPS, review the cardiac anomalies associated with the syndrome, and highlight the clinical challenges in intra-operative management of these patients.

Expanding the clinical history associated with syndromic Klippel-Feil: A unique case of comorbidity with medulloblastoma.

Klippel-Feil syndrome (KFS) is an exceedingly rare constitutional disorder in which a paucity of knowledge exists about the disease and its associated morbidity and mortality. We present a 4-year-old male with KFS, who notably was also diagnosed with large-cell anaplastic medulloblastoma. We evaluated the genetic basis of co-occurring KFS and medulloblastoma and the role of MYO18B as related to medulloblastoma. Constitutional and somatic variant and copy number analyses were performed from DNA-based exome studies, along with RNA-sequencing of tumor tissue, to elucidate the genetic etiology of the co-existing disease states. We identified novel constitutional compound heterozygous frameshift variants (NM_032608.5: p.Leu2257SerfsTer16 and p.Arg2220SerfsTer74) each encoding a premature stop of translation in MYO18B, consistent with a diagnosis of KFS. We did not identify any somatic variants of known relevance or disease-relevant therapeutic targets in the tumor. The somatic copy number profile was suggestive of Group 3γ medulloblastoma. Relative to pediatric brain tumors, medulloblastoma, particularly, Group 3, had increased gene expression of MYO18B. In summary, coexisting constitutional and somatic diagnoses in this patient enabled the elucidation of the genetic etiology of KFS and provided support for the role of MYO18B in tumor suppression.

[Klippel-Feil autosomal dominant syndrome: A malformation of vertebral segmentation]. / Síndrome de Klippel-Feil autosómico dominante: Una malformación de segmentación vertebral.

INTRODUCTION: Klippel-Feil syndrome is a highly heterogeneous complex skeletal disorder characterized by the con genital fusion of two or more cervical vertebrae. The classic clinical triad consists of a short neck, low hairline, and neck movements limitation. The associated mutations are located in the loci of the GDF3 gene (chromosome 12p13.31), GDF6 (chromosome 8q22.1), and MEOX1 (chromosome 17q21.31). OBJECTIVE: To describe the clinical-radiological findings and pedigree of a patient with Klippel-Feil syndrome. CLINICAL CASE: A 5-year-old patient with short neck, low posterior hairline, and limitation of lateral movements. The cervical flexion and extension radiographs showed fusion blocks between C1-2-3, C4-5, and C6-7. The chest CT scan showed multiple hemivertebrae in the upper third of the thoracic vertebrae corresponding to ribs I-IV. The karyotype was normal, 46, XX. Reduced penetrance was present in five of the family members. The fusion of C2-3 was present in four members and one individual had low fusion in C5-6. Three of the five affected individuals had a fusion between the capitate and the hamate bone. CONCLUSION: The malformation of congenital vertebral segmentation is a case of interest since it is an uncommon diagnosis in the pediatric age and whose clinical suspicion can be generated from the clinical examination, radiological study com plemented with the pedigree interpretation in Mendelian inheritance disorders, allowing to provide opportunely genetic counseling to the family.

Síndrome de Klippel-Feil autosómico dominante: una malformación de segmentación vertebral / Klippel-Feil autosomal dominant syndrome: a malformation of vertebral segmentation

INTRODUCCIÓN: El síndrome de Klippel-Feil constituye un desorden esquelético complejo altamente heterogéneo caracterizado por la fusión congénita de dos o más vértebras cervicales. La triada clínica clásica consiste en cuello corto, implantación baja del cabello y limitación para los movimientos del cue llo. Las mutaciones asociadas se localizan en los loci del gen GDF3 (cromosoma 12p13.31), GDF6 (cromosoma 8q22.1) y MEOX1 (cromosoma 17q21.31). OBJETIVO: Describir los hallazgos clínico- radiológicos y genealogía de una paciente con síndrome de Klippel-Feil. CASO CLÍNICO: Paciente de 5 años de edad con cuello corto, cabello de implantación baja posterior, limitación para los movimientos de lateralización. La radiografía cervical en flexión y extensión evidenció bloques de fusión entre C1-2-3, C4-5 y C6-7. En la tomografía axial computarizada de tórax se apreció múltiples hemivértebras del tercio superior de las vértebras torácicas correspondientes a las costillas I-IV. El cariotipo fue normal, 46, XX. La penetrancia reducida estuvo presente en cinco de los miembros de la familia. La fusión de C2-3 predominó en cuatro y en un individuo la fusión baja en C5-6. Tres de los cinco individuos afectados tenían fusión entre el hueso grande y ganchoso. CONCLUSIÓN: La malformación de segmentación vertebral congénita constituye un caso de interés por tratarse de un diagnóstico infrecuente en la edad pediátrica y cuya sospecha puede generarse a partir del examen clínico, estudio de imágenes complementado con la interpretación de la genealogía en los trastornos de herencia mendeliana, permitiendo brindar un oportuno asesoramiento genético a la familia.

INTRODUCTION: Klippel-Feil syndrome is a highly heterogeneous complex skeletal disorder characterized by the con genital fusion of two or more cervical vertebrae. The classic clinical triad consists of a short neck, low hairline, and neck movements limitation. The associated mutations are located in the loci of the GDF3 gene (chromosome 12pl3.31), GDF6 (chromosome 8q22.1), and MEOXI (chromosome 17q21.31). OBJECTIVE: To describe the clinical-radiological findings and pedigree of a patient with Klippel-Feil syndrome. CLINICAL CASE: A 5-year-old patient with short neck, low posterior hairline, and limitation of lateral movements. The cervical flexion and extension radiographs showed fusion blocks between C1-2-3, C4-5, and C6-7. The chest CT scan showed multiple hemivertebrae in the upper third of the thoracic vertebrae corresponding to ribs 1-tv. The karyotype was normal, 46, XX. Reduced penetrance was present in five of the family members. The fusion of C2-3 was present in four members and one individual had low fusion in C5-6. Three of the five affected individuals had a fusion between the capitate and the hamate bone. CONCLUSION: The malformation of congenital vertebral segmentation is a case of interest since it is an uncommon diagnosis in the pediatric age and whose clinical suspicion can be generated from the clinical examination, radiological study com plemented with the pedigree interpretation in Mendelian inheritance disorders, allowing to provide opportunely genetic counseling to the family.