A case report of multicentric carpotarsal osteolysis syndrome: Depiction of a debilitating disease course.

Multicentric carpotarsal osteolysis syndrome (MCTO) is a rare skeletal disorder characterized by progressive osteolysis involving the carpal and tarsal bones, and often associated with nephropathy. It is caused by heterozygous mutation in the MAF bZIP transcription factor B (MAFB) gene. Heterogeneous clinical manifestation and wide spectrum of disease severity have been observed in patients with MCTO. Here, we report a case of a male patient who presented with kidney failure in childhood with progressive disabling skeletal deformity. He was diagnosed with MCTO at 31-years-old, where a de novo pathogenic heterozygous variant in NM_005461.5:c.212C>A: p.(Pro71His) of the MAFB gene was identified. While there has been little data on the long-term prognosis and life expectancy of this disease, this case report sheds light on the debilitating disease course with multiple significant morbidities of a patient with MCTO throughout his lifetime of 33 years.

A novel variant in the ROR2 gene underlying brachydactyly type B: a case report.

BACKGROUND: Brachydactyly type B is an autosomal dominant disorder that is characterized by hypoplasia of the distal phalanges and nails and can be divided into brachydactyly type B1 (BDB1) and brachydactyly type B2 (BDB2). BDB1 is the most severe form of brachydactyly and is caused by truncating variants in the receptor tyrosine kinase-like orphan receptor 2 (ROR2) gene. CASE PRESENTATION: Here, we report a five-generation Chinese family with brachydactyly with or without syndactyly. The proband and her mother underwent digital separation in syndactyly, and the genetic analyses of the proband and her parents were provided. The novel heterozygous frameshift variant c.1320dupG, p.(Arg441Alafs*18) in the ROR2 gene was identified in the affected individuals by whole-exome sequencing and Sanger sequencing. The c.1320dupG variant in ROR2 is predicted to produce a truncated protein that lacks tyrosine kinase and serine/threonine- and proline-rich structures and remarkably alters the tertiary structures of the mutant ROR2 protein. CONCLUSION: The c.1320dupG, p.(Arg441Alafs*18) variant in the ROR2 gene has not been reported in any databases thus far and therefore is novel. Our study extends the gene variant spectrum of brachydactyly and may provide information for the genetic counselling of family members.

Talocalcaneal Tarsal Coalition Size: Evaluation and Reproducibility of MRI Measurements.

BACKGROUND: The size of talocalcaneal tarsal coalitions (TCCs) is one of the main factors that is thought to influence patient outcomes after resection. Magnetic resonance imaging (MRI) is increasingly being used to diagnose and characterize TCCs. However, there is no reproducible MRI-based measurement of TCC size reported in the literature. The purpose of this study was to create a method to reproducibly measure TCC size using MRI. METHODS: Twenty-seven patients with TCCs diagnosed by a hindfoot coronal proton density (PD) MRI between 2017 and 2020 were included. Five independent raters measured coalition width, healthy posterior facet width, and healthy middle facet width on individual slices of coronal PD hindfoot MRIs using discrete MRI measurement guidelines. Individual slice measurements were summed to determine total size of the coalition and the remaining healthy cartilage of the posterior and middle facets. Inter-rater reliability of MRI measurements between the 5 independent examiners was evaluated using intraclass correlation coefficient (ICC). ICC was calculated for total coalition width, total healthy posterior facet width, total coalition width/total healthy posterior facet width, total coalition width/total healthy middle facet width, total coalition width/total healthy subtalar facet width (posterior facet+middle facet), and total coalition width/total subtalar facet width (coalition+posterior facet+middle facet). RESULTS: The ICC scores for all but one of the MRI measurements indicated good to excellent inter-rater reliability among the 5 examiners. The ICC was 0.932 (95% confidence interval: 0.881-0.966) for measurement of total coalition width/total healthy posterior facet width and 0.948 (95% confidence interval: 0.908-0.973) for measurement of total coalition width/total subtalar facet width (middle+posterior+coalition). CONCLUSIONS: Measurements of coalition size using novel MRI guidelines were reproducible with good to excellent inter-rater reliability. These guidelines allow for determination of TCC size using coronal PD MRI. LEVEL OF EVIDENCE: Level II-diagnostic reproducibility study.

8 out of 10 patients do well after surgery for tarsal coalitions: A systematic review on 1284 coalitions.

BACKGROUND: The primary aim was to determine the clinical success rate after treatment for talocalcaneal (TCC) and calcaneonavicular coalitions (CNC). The secondary aim was to evaluate the complication, recurrence and revision rate. METHODS: A search was carried out in MEDLINE, EMBASE and Cochrane Library. Methodological quality was assessed using the Methodological Index for Non-Randomised Studies (MINORS) criteria. The primary outcome was the clinical success rate and was pooled per type of coalition and treatment modality. 95% Confidence Intervals (CI) of the success rates were calculated. Secondary outcomes included complication rates, coalition recurrence rates, revision rates and pain improvement using the Visual Analogue Scale (VAS). A sub-analysis on interposition material was performed. RESULTS: 43 articles comprising of 1284 coalitions were included, with a pooled mean follow-up of 51 months. Methodological quality was fair. The overall pooled success rate for TCCs was 79% (95% CI, 75%-83%). Conservative treatment, open resection and arthroscopic resection of TCCs resulted in success rates of 58% (95% CI, 42%-73%), 80% (95% CI, 76%-84%) and 86% (95% CI, 71%-94%), respectively. CNCs have an overall success rate of 81% (95% CI, 75%-85%), with 100% (95% CI, 34%-100%), 80% (95% CI, 74%-85%) and 100% (95% CI, 65%-100%) for conservative treatment, open resection and arthroscopic resection, respectively. Pooled complication rates of 4% (95% CI, 3%-7%) for TCCs and 6% (95% CI, 4%-11%) for CNCs were found. The success rates of resection with and without interposition material for TCCs were 83% (95% CI, 78%-87%) and 79% (95% CI, 65%-88%), and for CNCs 81% (95% CI, 76%-86%) and 69% (95% CI, 44%-85%), respectively. CONCLUSION: Treatment of tarsal coalitions can be considered good to excellent as well as safe, with an overall clinical success rate of 79% for TCCs and 81% for CNCs. Arthroscopic resection of the coalition appears to be non-inferior to open resection of TCCs and CNCs. LEVEL OF EVIDENCE: Level IV, Systematic Review.

Clinical observation and genetic analysis of a SYNS1 family caused by novel NOG gene mutation.

OBJECTIVE: Analyze the clinical and genetic characteristics of a rare Chinese family with Multiple synostoses syndrome and identify the causative variant with the high-throughput sequencing approach. METHODS: The medical history investigation, physical examination, imaging examination, and audiological examination of the family members were performed. DNA samples were extracted from the family members. The candidate variant was identified by performing whole-exome sequencing of the proband, then verified by Sanger sequencing in the family. RESULTS: The family named HBSY-018 from Hubei province had 18 subjects in three generations, and six subjects were diagnosed with conductive or mixed hearing loss. Meanwhile, characteristic features including short philtrum, hemicylindrical nose, and hypoplastic alae nasi were noticed among those patients. Symptoms of proximal interdigital joint adhesion and inflexibility were found. The family was diagnosed as Multiple synostoses syndrome type 1 (SYNS1).The inheritance pattern of this family was autosomal dominant. A novel mutation in the NOG gene c.533G>A was identified by performing whole-exome sequencing of the proband. The substitution of cysteine encoding 178th position with tyrosine (p.Cys178Tyr) was caused by this mutation, which was conserved across species. Co-segregation of disease phenotypes was demonstrated by the family verification. CONCLUSION: The family diagnosed as SYNS1 was caused by the novel mutation (c.533G>A) of NOG. The combination of clinical diagnosis and molecular diagnosis had improved the understanding of this rare disease and provided a scientific basis for genetic counseling in the family.

Natural Progression and Symptomatic Management of Tarsal-Carpal Coalition Syndrome: A Case Report.

CASE: Tarsal-carpal coalition syndrome (TCCS) is a disorder identified by fusion of the carpals, tarsals, and phalanges of the hands and feet. We describe a case of an 11-year-old girl who has been followed at our outpatient clinic from the age of 8 months. CONCLUSION: Although patients with TCCS can experience a wide range of symptoms, the primary complaint arises from the foot deformity and associated pain. Using advanced imaging such as 3D computed tomography reconstruction and genetic testing, this report details the clinical, genetic, and radiographic characteristics of the disorder. We highlight the natural progression and symptomatic management of TCCS.

Genetic Heterogeneity and Core Clinical Features of NOG-Related-Symphalangism Spectrum Disorder.

OBJECTIVES: To better distinguish NOG-related-symphalangism spectrum disorder (NOG-SSD) from chromosomal 17q22 microdeletion syndromes and to inform surgical considerations in stapes surgery for patients with NOG-SSD. BACKGROUND: Mutations in NOG cause a variety of skeletal syndromes that often include conductive hearing loss. Several microdeletions of chromosome 17q22 lead to severe syndromes with clinical characteristics that overlap NOG-SSD. Isolated deletion of NOG has not been described, and therefore the contribution of NOG deletion in these syndromes is unknown. METHODS: Two families with autosomal dominant NOG-SSD exhibited stapes ankylosis, facial dysmorphisms, and skeletal and joint anomalies. In each family, NOG was evaluated by genomic sequencing and candidate mutations confirmed as damaging by in vitro assays. Temporal bone histology of a patient with NOG-SSD was compared with temporal bones of 40 patients diagnosed with otosclerosis. RESULTS: Family 1 harbors a 555 kb chromosomal deletion encompassing only NOG and ANKFN1. Family 2 harbors a missense mutation in NOG leading to absence of noggin protein. The incus-footplate distance of the temporal bone was significantly longer in a patient with NOG-SSD than in patients with otosclerosis. CONCLUSION: The chromosomal microdeletion of family 1 led to a phenotype comparable to that due to a NOG point mutation and much milder than the phenotypes due to other chromosome 17q22 microdeletions. Severe clinical findings in other microdeletion cases are likely due to deletion of genes other than NOG. Based on temporal bone findings, we recommend that surgeons obtain longer stapes prostheses before stapes surgery in individuals with NOG-SSD stapes ankylosis.

A family with partially penetrant multicentric carpotarsal osteolysis due to gonadal mosaicism: First reported case.

Multicentric carpotarsal osteolysis (MCTO) is an autosomal dominant condition characterized by carpal-tarsal abnormalities; over half of affected individuals also develop renal disease. MCTO is caused by mutations of MAFB; however, there is no clear phenotype-genotype correlation. We describe the first reported family of variable MCTO phenotype due to mosaicism: the proband had classical skeletal features and renal involvement due to focal segmental glomerulosclerosis (FSGS), and the father had profound renal impairment due to FSGS, necessitating kidney transplantation. Mosaicism was first suspected in this family due to unequal allele ratios in the sequencing chromatograph of the initial blood sample of proband's father and confirmed by sequencing DNA extracted from the father's hair, collected from different bodily parts. This case highlights the need for a high index of clinical suspicion to detect low-level parental mosaicism, as well as a potential role for MAFB mutation screening in individuals with isolated FSGS.

Extreme bilateral polydactyly in a wild-caught western grey kangaroo.

Polydactyly is a congenital malformation resulting from an autosomal dominant mutation manifesting as supernumerary digits of the hands or feet. It is most commonly reported in humans and domestic mammals, though there have also been isolated examples across a range of wild vertebrate species. Here we report a case of extremely unusual bilateral preaxial polydactyly on the pectoral limbs of a male western grey kangaroo (Macropus fuliginosus) from the South West region of Western Australia, in which two supernumerary digits were present on each manus. A supernumerary digit I on each manus was rudimentary in morphology without extrinsic muscular connections. However, supernumerary digit II present on each manus had fully developed extrinsic and intrinsic muscular connections, suggesting that these digits possessed normal function in flexion and extension. An alternative hypothesis is that the two supernumerary digits are both representatives of the most radial digit I, though this would then require the true digit I to have taken on the appearance of digit II by acquiring an additional phalanx and modified muscular attachments. The carpal bones exhibited a number of subtle differences in morphology when compared to normal pentadactyl individuals. The presence of a distal, rather than proximal, epiphysis on the first metacarpal was unexpected but further investigation suggested that this characteristic is perhaps more variable (in this species at least) than has been previously recognized. This case provides an unusual example to be considered within the broader context of limb development.

Genetic and clinical phenotypic analysis of familial stapes sclerosis caused by an NOG mutation.

BACKGROUND: The noggin protein encoded by the NOG gene can interfere with the binding of bone morphogenetic protein to its receptor, thus affecting bone and joint development. The symptoms include abnormal skeletal development and conductive deafness. METHODS: In a retrospective study, clinical data of the proband and her family members, including 8 people and 50 healthy normal controls, were collected. Second-generation sequencing was performed on peripheral blood samples from them. RESULTS: The sequencing analysis indicated that in the proband, the NOG gene had a c.532T > C, p.C178R (cytosine deletion, NM_005450.6:c.532T > C), leading to an amino acid change. The proband's father, grandmother, second sister, and third sister also had this mutation, whereas family members with normal phenotypes did not have the mutation. CONCLUSION: Analysis of this family showed that the novel presentation of the c.532T > C, p.C178R mutation in the NOG gene resulted in syndrome-type autosomal dominant inheritance reflected in a mild clinical phenotype, which is of great importance for further studies of the clinical phenotype and pathogenesis of stapes sclerosis.

Multiple synostoses syndrome: Clinical report and retrospective analysis.

Multiple synostoses syndrome (SYNS1; OMIM# 186500) is a rare autosomal dominant disorder reported in a few cases worldwide. We report a Chinese pedigree characterized by proximal symphalangism, conductive hearing loss, and distinctive facies. We examined the genetic cause and reviewed the literature to discuss the pathogeny, treatment, and prevention of SYNS1. Audiological, ophthalmological, and radiological examinations were evaluated. Whole-exome sequencing (WES) was performed to identify mutations in the proband and her parents. Sanger sequencing was used to verify the results for the proband, parents, and grandmother. The literature on the genotype-phenotype correlation was reviewed. The patient was diagnosed with multiple synostoses syndrome clinically. WES and bioinformatic analysis revealed a novel missense mutation in the NOG gene, c.554C>G (p.Ser185Cys), cosegregated in this family. The literature review showed that the phenotype varies widely, but the typical facies, conductive hearing loss, and proximal symphalangism occurred frequently. All reported mutations are highly conserved in mammals based on conservation analysis, and there are regional hot spots for these mutations. However, no distinct genotype-phenotype correlations have been identified for mutations in NOG in different races. Regular systematic examinations and hearing aids are beneficial for this syndrome. However, the outcomes of otomicrosurgery are not encouraging owing to the regrowth of bone. This study expanded the mutation spectrum of NOG and is the first report of SYNS1 in a Chinese family. Genetic testing is recommended as part of the diagnosis of syndromic deafness. A clinical genetic evaluation is essential to guide prevention, such as preimplantation genetic diagnosis.

Tarsal-carpal coalition syndrome: importance of early diagnosis.

Tarsal-carpal coalition syndrome is a progressive condition involving synostosis of the wrist, ankle and digits. We describe a mother and her newborn that have this rare inherited condition where the diagnosis was made only after the baby's birth. The baby's condition was suspected on antenatal scanning, and he was born with reduced range of motion of his digits, elbows and ankles. The mother's condition has progressed to involve a fixed flexion deformity of her bilateral elbows, synostoses of her second to fifth digits and extensive coalition of her tarsal and carpal bones. She has required regular osteotomies to improve limb functioning and quality of life.

Deficiencia radial longitudinal. Análisis de resultados clínicos y radiológicos / Radial longitudinal deficiency. Analysis of clinical and radiological results

Introducción: La deficiencia radial longitudinal comprende anormalidades óseas, musculotendinosas y neurovasculares de etiología multifactorial del lado radial de la extremidad superior. El tratamiento incluye mejorar la longitud, la apariencia y el funcionamiento de la mano. El objetivo del trabajo es mostrar la experiencia en una serie de pacientes atendidos en los últimos 15 años y describir resultados clínicos y radiológicos. Metodología: Estudio retrospectivo de pacientes con deficiencia radial longitudinal entre 2000 a 2016. Se analizaron variables y se identificaron asociaciones de edad al momento de cirugía, sexo, lateralidad, grado de la deformidad según la clasificación Bayne-Klug modificada, técnica quirúrgica realizada, daño de la fisis, enfermedades asociadas, resultados funcionales y radiológicos. Resultados: Cuarenta y siete casos de 65 cumplían con criterios de inclusión. La edad promedio de la cirugía fue de 19 meses, 61% de sexo femenino. Según la clasificación el tipo IV fue el 60%, el tipo III el 19%, el tipo 0 el 17% y tipo I el 4%. La intervención practicada fue la centralización en el 72,3%, la radialización en el 8,5% y hubo un caso de alargamiento. Se realizó osteotomía de cúbito en el 55,3%. Hubo daño de la fisis en el 31%. La posición radiológica postoperatoria fue neutra en el 48,9%. Conclusiones: En pacientes con centralización a un año se observa una buena corrección clínica y radiológica, sin embargo esta se va perdiendo con el tiempo. El tratamiento de los tejidos blandos previo a la centralización se cree que permite obtener mejores resultados. El uso de clavo intramedular del cúbito al carpo podría estar asociado con daño de fisis del cúbito distal

Introduction: radial longitudinal deficiency (RLD) includes bone, musculotendinous and neurovascular abnormalities of multifactorial aetiology of the radial side of the upper extremity. Treatment includes improving the length of the limb, the appearance and functioning of the hand. The aim of this study was to present our experience in a series of patients attended over the past 15 years and to describe the clinical and radiological results. Methodology: a retrospective study of patients with RLD between 2000 and 2016. Variables were analyzed and age associations were identified at the time of surgery, sex, laterality, type of deformity according to the modified Bayne-Klug classification, surgical technique, physis damage, associated diseases, functional and radiological results. Results: 47 cases of 65 met the inclusion criteria. The average age of surgery was 19 months, 61% female. According to classification 60% were type IV, type III 19%, type 0 in 17% and type I in 4%. The intervention was centralization 72.3%, radialization 8.5% and one case of lengthening. Ulna osteotomy was performed in 55.3%. There was damage to the physis in 31%. The postoperative radiological position was neutral in 48.9%. Conclusions: In patients with centralization at 1year, good clinical and radiological correction were observed, however this was lost over time. The management of soft tissues prior to centralization is believed to give better results. The use of intramedullary nail from the ulna to the carpus could be associated with damage to the distal ulna

H2AFY promoter deletion causes PITX1 endoactivation and Liebenberg syndrome.

BACKGROUND: Structural variants (SVs) affecting non-coding cis-regulatory elements are a common cause of congenital limb malformation. Yet, the functional interpretation of these non-coding variants remains challenging. The human Liebenberg syndrome is characterised by a partial transformation of the arms into legs and has been shown to be caused by SVs at the PITX1 locus leading to its misregulation in the forelimb by its native enhancer element Pen. This study aims to elucidate the genetic cause of an unsolved family with a mild form of Liebenberg syndrome and investigate the role of promoters in long-range gene regulation. METHODS: Here, we identify SVs by whole genome sequencing (WGS) and use CRISPR-Cas9 genome editing in transgenic mice to assign pathogenicity to the SVs. RESULTS: In this study, we used WGS in a family with three mildly affected individuals with Liebenberg syndrome and identified the smallest deletion described so far including the first non-coding exon of H2AFY. To functionally characterise the variant, we re-engineered the 8.5 kb deletion using CRISPR-Cas9 technology in the mouse and showed that the promoter of the housekeeping gene H2afy insulates the Pen enhancer from Pitx1 in forelimbs; its loss leads to misexpression of Pitx1 by the pan-limb activity of the Pen enhancer causing Liebenberg syndrome. CONCLUSION: Our data indicate that housekeeping promoters may titrate promiscuous enhancer activity to ensure normal morphogenesis. The deletion of the H2AFY promoter as a cause of Liebenberg syndrome highlights this new mutational mechanism and its role in congenital disease.

Radial longitudinal deficiency. Analysis of clinical and radiological results. / Deficiencia radial longitudinal. Análisis de resultados clínicos y radiológicos.

INTRODUCTION: radial longitudinal deficiency (RLD) includes bone, musculotendinous and neurovascular abnormalities of multifactorial aetiology of the radial side of the upper extremity. Treatment includes improving the length of the limb, the appearance and functioning of the hand. The aim of this study was to present our experience in a series of patients attended over the past 15 years and to describe the clinical and radiological results. METHODOLOGY: a retrospective study of patients with RLD between 2000 and 2016. Variables were analyzed and age associations were identified at the time of surgery, sex, laterality, type of deformity according to the modified Bayne-Klug classification, surgical technique, physis damage, associated diseases, functional and radiological results. RESULTS: 47 cases of 65 met the inclusion criteria. The average age of surgery was 19 months, 61% female. According to classification 60% were type IV, type III 19%, type 0 in 17% and type I in 4%. The intervention was centralization 72.3%, radialization 8.5% and one case of lengthening. Ulna osteotomy was performed in 55.3%. There was damage to the physis in 31%. The postoperative radiological position was neutral in 48.9%. CONCLUSIONS: In patients with centralization at 1year, good clinical and radiological correction were observed, however this was lost over time. The management of soft tissues prior to centralization is believed to give better results. The use of intramedullary nail from the ulna to the carpus could be associated with damage to the distal ulna.

Autosomal dominant stapes fixation, syndactyly, and symphalangism in a family with NOG mutation: Long term follow-up on surgical treatment.

OBJECTIVE: Evaluation of clinical findings and audiological outcome after surgery in a Danish family with autosomal dominant facio-audio-symphalangism syndrome with stapes fixation, syndactyly and symphalangism. METHODS: Retrospective report on eight affected family members in a Danish family. Clinical investigation included X-ray, audiology and in one case video-recorded surgery. Main outcome measure was audiologic results after stapedectomy. Sanger DNA sequencing of NOG was performed on peripheral blood. RESULTS: Audiologic analysis showed that seven of eight affected family members had bilateral conductive hearing loss. Three patients were treated with stapedectomy, on one or both ears, due to fixation of stapes. All the affected members had syndactyly and symphalangism. A not previously reported mutation in the NOG gene (c.688_699del, p.Cys230_Cys232delins11) was found to segregate with the stapes fixation, syndactyly, and symphalangism. p.Cys230_Cysdelins11 was classified as likely pathogenic according to guidelines from the American College of Medical Genetics and Genomics. CONCLUSION: The clinical presentation of the reported mutation corresponds with previous case reports of families with NOG mutation. In this family, surgery with stapedectomy had lasting effect without renewed fixation of the stapes in a follow up period of 18 months-38 years.

Tarsal-carpal coalition syndrome: Report of a novel missense mutation in NOG gene and phenotypic delineation.

We report a family of Indian origin presenting with Tarsal-carpal coalition syndrome (TCC), which is a rare genetic disorder of skeletal abnormalities, inherited in autosomal dominant manner. In this family, three individuals (mother and two children) were found to be similarly affected with slight intrafamilial individual variability in the phenotype. Sanger sequencing revealed a novel heterozygous missense mutation in NOG gene (NM_005450.4:c.611G>A) in all the affected individuals of the family. Until now only six mutations have been reported in different families affected with TCC syndrome worldwide. This report further delineates the phenotypic spectrum of this rare disorder with the addition of a new variant to the mutation spectrum.

A retrospective study of radiographic abnormalities in the repositories for Thoroughbreds at yearling sales in Japan.

This study aimed to evaluate whether radiographic abnormalities at yearling sales were associated with the failure to start racing at 2-3 years of age. Radiographic abnormalities in the carpal (n=852), tarsal (n=976), metacarpophalangeal (n=1,055), and metatarsophalangeal joints (n=1,031) from 1,082 horses, recorded at yearling sale, were reviewed. Eighty-two horses (7.6%) failed to start racing. Radiographic abnormalities such as wedged or collapsed tarsal bones, irregular lucency of a sagittal ridge at the distal aspect of the distal third metatarsal bone, and proximal dorsal fragmentation of the first phalanx in metatarsophalangeal joints were associated with failure to start racing in these horses. In the follow-up survey of 12 horses with one or more these radiographic abnormalities, the horses failed to start racing due to reasons unrelated to these radiographic abnormalities such as pelvic fractures (2 horses), fracture of a distal phalanx (1 horse), cervical stenotic myelopathy and proximal sesamoid fracture (1 horse), superficial digital flexor tendonitis (2 horses), laryngeal hemiplegia (1 horse), economic problems (2 horses) and unknown causes (3 horses). Although radiographic abnormalities at yearling sales can be associated with failure to start racing at 2-3 years of age, these radiographically detected abnormalities might not necessarily cause that failure.