Stüve-Wiedemann syndrome in children surviving infancy: clinical and radiological features

Paediatric survivors beyond infancy with Stüve-Wiedemann syndrome - A case series from the West Midlands, UK

Stüve-Wiedemann Syndrome (STWS) is an autosomal recessive condition caused by variants in the LIFR gene, presenting with respiratory failure, hyperthermia and skeletal dysplasia in the neonatal period. Historically identified as a lethal condition, more children are now managed holistically from early in life with multidisciplinary team involvement with improved outcomes. This stems from early diagnosis, supported by molecular testing in the pre and postnatal periods. This report includes five such cases with survival in childhood to 10 years old in the UK affected by skeletal abnormalities, hyperthermia, respiratory distress and their diagnostic odyssey. All cases have a molecular diagnosis; two patients (family 1) were found to be homozygous for a novel pathogenic LIFR variant NM_002310.5:c.704G > A, p.(Trp235Ter). One patient (family 2) is compound heterozygous with the previously reported LIFR variant NM_002310.5:c.756dup p.(Lys253Ter), and a second novel variant NM_002310.5:c.397+5G > A. Two patients (family 3) are homozygous for one of the same LIFR variants NM_002310.5:c.756dup p.(Lys253Ter) as in family 2. This report discusses genotypic and phenotypic data for five patients with STWS, as well as the need for multi-disciplinary, proactive management and genetic counselling.

Clinical overview and outcome of the Stuve-Wiedemann syndrome: a systematic review

BACKGROUND

Stuve-Wiedemann syndrome (SWS) is a rare and severe genetic disease characterized by skeletal anomalies and dysautonomic disturbances requiring appropriate care. Peer support is mandatory to fill the lack of clinical recommendations in such rare diseases. We report a new case and provide the first systematic review of all previous published cases.

OBJECTIVE

To better describe the timeline of SWS and to improve paediatric management.

DATA SOURCES

SWS English publications available on Pubmed until 31/03/2021.

STUDY SELECTION

Case description combining typical osteo-articular and dysautonomic involvement (with 2 items by categories required for children < 2 years and 3 items > 2 years).

DATA EXTRACTION

Demographic, clinical, genetics and outcome data.

RESULTS

In our cohort of 69 patients, the median age at report was 32 months. Only 46% presented antenatal signs. Mortality rate is higher during the first 2 years (42% < 2 years; 10% > 2 years) mainly due to respiratory failure, pulmonary arterial hypertension appearing to be a poor prognosis factor (mortality rate 63%). After 2 years, orthopaedic symptoms significantly increase including joint mobility restriction (81%), spinal deformations (77%) and fractures (61%).

CONCLUSIONS

Natural history of SWS is marked by a high mortality rate before 2 years due to dysautonomic disturbances. A specialized multidisciplinary approach is needed to address these early mortality risks and then adapt to the specific, mainly orthopaedic, needs of patients after 2 years of age. Further research is required to provide clinical guidelines and improve pre-natal counselling.

Delineation of the clinical and radiological features of Stuve-Wiedemann syndrome childhood survivors, four new cases and review of the literature

Stuve-Wiedemann syndrome (SWS; MIM 601559) is a rare autosomal recessive disease caused by mutations in the leukemia inhibitor factor receptor gene (LIFR). Common clinical and radiological findings are often observed, and high neonatal mortality occurs due to respiratory distress and hyperthermic episodes. Despite initially considered as a lethal disorder during the newborn period, in recent years, several SWS childhood survivors have been reported. We report a detailed clinical and radiological characterization of four unrelated childhood SWS molecularly confirmed patients and review 22 previously reported childhood surviving cases. We contribute to the definition of the childhood survival phenotype of SWS, emphasizing the evolving phenotype, characterized by skeletal abnormalities with typical radiological findings, distinctive dysmorphic features, and dysautonomia. Based on the typical features and clinical course, early diagnosis is possible and crucial to plan appropriate management and prevent potential complications. Genetic confirmation is advisable in order to improve genetic counseling to the patients and their families.

FAM46A mutations are responsible for autosomal recessive osteogenesis imperfecta

BACKGROUND

Stüve-Wiedemann syndrome (SWS) is characterised by bowing of the lower limbs, respiratory distress and hyperthermia that are often responsible for early death. Survivors develop progressive scoliosis and spontaneous fractures. We previously identified LIFR mutations in most SWS cases, but absence of LIFR pathogenic changes in five patients led us to perform exome sequencing and to identify homozygosity for a FAM46A mutation in one case [p.Ser205Tyrfs*13]. The follow-up of this case supported a final diagnosis of osteogenesis imperfecta (OI), based on vertebral collapses and blue sclerae.

METHODS AND RESULTS

This prompted us to screen FAM46A in 25 OI patients with no known mutations.We identified a homozygous deleterious variant in FAM46A in two affected sibs with typical OI [p.His127Arg]. Another homozygous variant, [p.Asp231Gly], also classed as deleterious, was detected in a patient with type III OI of consanguineous parents using homozygosity mapping and exome sequencing.FAM46A is a member of the superfamily of nucleotidyltransferase fold proteins but its exact function is presently unknown. Nevertheless, there are lines of evidence pointing to a relevant role of FAM46A in bone development. By RT-PCR analysis, we detected specific expression of FAM46A in human osteoblasts andinterestingly, a nonsense mutation in Fam46a has been recently identified in an ENU-derived (N-ethyl-N-nitrosourea) mouse model characterised by decreased body length, limb, rib, pelvis, and skull deformities and reduced cortical thickness in long bones.

CONCLUSION

We conclude that FAM46A mutations are responsible for a severe form of OI with congenital bowing of the lower limbs and suggest screening this gene in unexplained OI forms.

Developments in the Orthopaedic Management of Children With Stüve-Wiedemann Syndrome: Use of the Fassier-Duval Telescopic Rod to Maintain Correction of Deformity

BACKGROUND

Stüve-Wiedemann syndrome is a rare inherited condition, which is frequently fatal in infancy. Those patients who survive into childhood demonstrate a complex progressive deformity of the long bones, with high rates of recurrence after initial successful correction. Because of the rarity of the condition there is, at present, limited evidence on the most appropriate treatment.

METHODS

We describe our experience in the management of 4 patients, who underwent correction of deformity and fixation with Fassier-Duval telescopic rods.

RESULTS

In this series we have seen good correction of deformity and maintenance of alignment, with improvement in the walking ability of children treated with this technique.

CONCLUSION

Fassier-Duval rodding has a role in the prevention of recurrence of deformity and should be considered as a means to reduce the number of operative procedures required.

LEVEL OF EVIDENCE

Level IV-therapeutic.

Neuropathies of Stüve-Wiedemann Syndrome due to mutations in leukemia inhibitory factor receptor (LIFR) gene

Stüve-Wiedemann syndrome (STWS; OMIM #610559) is a rare disease that results in dysfunction of the autonomic nervous system, which controls involuntary processes such as breathing rate and body temperature. In infants, this can result in respiratory distress, feeding and swallowing difficulties, and hyperthermic episodes. Individuals may sweat excessively when body temperature is not elevated. Additionally, individuals have reduced ability to feel pain and may lose reflexes such as the corneal reflex that normally causes one to blink, and the patellar reflex resulting in the knee-jerk. STWS usually results in infant mortality, yet some STWS patients survive into early adulthood. STWS is caused by a mutation in the leukemia inhibitory factor receptor (LIFR) gene, which is inherited in an autosomal-recessive pattern. Most LIFR mutations resulting in STWS cause instability of the mRNA due to frameshift mutations leading to premature stop codons, which prevent the formation of LIFR protein. STWS is managed on a symptomatic basis as no treatment is currently available.

Stüve-Wiedemann Syndrome: Update on Clinical and Genetic Aspects

Stüve-Wiedemann syndrome is a rare autosomal recessive disorder characterized by bowed long bones, joint restrictions, dysautonomia, and respiratory and feeding difficulties, leading to death in the neonatal period and infancy in several occasions. Since the first cases in 1971, much has been learned about this condition, including its molecular basis - mutations in the leukemia inhibitory factor receptor gene (LIFR) -, natural history and management possibilities. This review aims to highlight the clinical aspects, radiological features, molecular findings, and management strategies in Stüve-Wiedemann syndrome.

Non-truncating LIFR mutation: causal for prominent congenital pain insensitivity phenotype with progressive vertebral destruction?

We present a Qatari family with two children who displayed a characteristic phenotype of congenital marked pain insensitivity with hypohidrosis and progressive aseptic destruction of joints and vertebrae resembling that of hereditary sensory and autonomic neuropathies (HSANs). The patients, aged 10 and 14, remained of uncertain genetic diagnosis until whole genome sequencing was pursued. Genome sequencing identified a novel homozygous C65S mutation in the LIFR gene that is predicted to markedly destabilize and alter the structure of a particular domain and consequently to affect the functionality of the whole multi-domain LIFR protein. The C65S mutant LIFR showed altered glycosylation and an elevated expression level that might be attributed to a slow turnover of the mutant form. LIFR mutations have been reported in Stüve-Wiedemann syndrome (SWS), a severe autosomal recessive skeletal dysplasia often resulting in early death. Our patients share some clinical features of rare cases of SWS long-term survivors; however, they also phenocopy HSAN due to the marked pain insensitivity phenotype and progressive bone destruction. Screening for LIFR mutations might be warranted in genetically unresolved HSAN phenotypes.

Stüve-Wiedemann syndrome in a neonate

We describe a female neonate with Stüve-Wiedemann syndrome. The facial dysmorphism, joint contracture, distinctive skeletal changes, and myotonic discharges on electromyogram raised a suspicion of the rare autosomal recessive syndrome, which was later confirmed on molecular analysis of leukemia inhibitory factor receptor. She developed recurrent attacks of hyperpyrexia and died at age 3 months.

Stuve-Wiedemann syndrome: is it underrecognized?

Stuve-Wiedemann Syndrome (SWS) (OMIM #601559) is an autosomal recessive disorder characterized by skeletal changes, bowing of the lower limb, severe osteoporosis and joint contractures, episodic hyperthermia, frequent respiratory infections, feeding problems and high mortality in early life. It is caused by mutation in the leukemia inhibitory factor receptor gene (LIFR; 151443) on chromosome 5p13. We provide the clinical follow-up and molecular aspects of six new patients who carried the same novel mutation in the LIFR gene (p.Arg692X) and three patients carried a common haplotype at the LIFR locus supporting a founder effect in the Turkish population. The probable pathogenesis of the features is also discussed. Osseous findings in the presence of other above-mentioned morbid conditions should raise the suspicion of SWS in neonates especially in Arabic and Eastern Mediterranean countries with high rate of consanguineous marriages like in Turkey. Severe osteoporosis, bone deformities, milias, leukocoria, inflammatory lesions on distal extremities, tongue biting behavior and oral ulcers could be more prominent features of the survivors beyond the neonatal period while respiratory and feeding problems are remitting. It is of crucial importance to diagnose such babies earlier in order to prevent extensive laboratory workup and to provide proper genetic counseling.

Stüve-Wiedemann syndrome: LIFR and associated cytokines in clinical course and etiology

Stüve-Wiedemann syndrome (STWS; OMIM #610559) is a rare bent-bone dysplasia that includes radiologic bone anomalies, respiratory distress, feeding difficulties, and hyperthermic episodes. STWS usually results in infant mortality, yet some STWS patients survive into and, in some cases, beyond adolescence. STWS is caused by a mutation in the leukemia inhibitory factor receptor (LIFR) gene, which is inherited in an autosomally recessive pattern. Most LIFR mutations resulting in STWS are null mutations which cause instability of the mRNA and prevent the formation of LIFR, impairing the signaling pathway. LIFR signaling usually follows the JAK/STAT3 pathway, and is initiated by several interleukin-6-type cytokines. STWS is managed on a symptomatic basis since there is no treatment currently available.

Delayed Tetraplegia After Thoracolumbar Scoliosis Surgery in Stuve-Wiedemann Syndrome

OBJECTIVE

We present 2 patients with Stuve-Wiedemann syndrome (SWS) who suffered delayed tetraparesis following posterior spinal surgery for scoliosis.

BACKGROUND SUMMARY

Delayed tetraparesis after a syndromic thoracic scoliosis correction has never been reported. A cord injury distant from the surgical site is rare, and intraoperative neuromonitoring should be used to detect and prevent neurologic impairment.

METHODS

Review of medical charts.

RESULTS

Two patients with SWS suffered delayed tetraparesis 20 and 40 hours respectively after thoracolumbar posterior surgery. In one patient distal motor evoked potentials fell and recovered partially during surgery. In both patients, early postoperative neurologic examination was normal (in one of them except for the extensor hallucis 2/5). CT scan showed correct instrumentation placement and no compressive haematoma. MRI ruled out cord anomalies, but revealed in both patients identical cervical edema that was most likely secondary to ischemia. Angiogram revealed an absence of anterior cord vascular supply.

CONCLUSIONS

Correction of severe deformities in syndromic patients may lead to stretch injuries of the spinal cord and its vascular supply. This in turn may lead to a neurological deficit extending beyond the limits of the spinal instrumentation. Abrupt postoperative neck pain may be an alert to this impending development. Close surveillance in the early postoperative period should be maintained in patients with SWS because a delayed neurological deficit can be present even hours afterwards and may be cranial to the surgical level.

Ocular treatment of children with Stuve-Wiedemann syndrome

PURPOSE

Stuve-Wiedemann syndrome is a rare condition consisting of bone dysplasia, hypotony, and dysautonomia with ocular and neuropathic features. We present the ocular findings and visual outcome in 4 patients (2 siblings, 1 related cousin, and 1 unrelated patient) with this syndrome.

METHODS

A retrospective case series review. Clinical notes of 4 patients with Stuve-Wiedemann syndrome were reviewed for findings of systemic features, ocular examination, visual acuity, and ocular procedures.

RESULTS

The median age at presentation was 16 months (range, 14-72 months). All 4 cases consisted of bilateral plaque-like corneal scarring with reduced corneal sensation. Treatment comprised topical lubrication, punctal plugs, lateral tarsorrhaphies, surgical optical iridectomies when required, and aggressive visual rehabilitation with frequent refraction and occlusion therapy if necessary. Mean best-corrected visual acuity (BCVA) in the eye with best vision was 0.86 logarithm of the minimum angle of resolution (logMAR) (range, 0.72-1.1 logMAR) at presentation and 0.43 logMAR (range, 0.25-0.56 logMAR) at the last follow-up. The BCVA in the eye with worst vision was 0.98 logMAR (range, 0.72-1.3 logMAR) at presentation and 0.68 logMAR (range, 0.47-1.0 logMAR) at the last follow-up. The median follow-up was 3.2 years (range, 1.1-5.8 years).

CONCLUSIONS

All of our patients showed improved BCVA with the treatment regimen prescribed. Given these children's debilitating orthopedic problems, visual function is important and has hitherto been reported as being poor.

Stüve-Wiedemann syndrome and related bent bone dysplasias

Stüve-Wiedemann syndrome (SWS) is a severe congenital skeletal dysplasia associated with life threatening dysautonomic manifestations. Newborns affected with this condition exhibit distinctive shortening and bowing of the long bones with reduced bone volume. The majority of affected newborns die early due to neuromuscular complications namely hyperthermia, apnea, and swallowing difficulties. In this review, we provide an overall picture on the clinical, including long-term management, molecular and cellular aspects of SWS and discuss briefly other related bent bone dysplasias.

Stuve-Wiedemann syndrome: a skeletal dysplasia characterized by bowed long bones

OBJECTIVE

To describe the prenatal sonographic features of Stuve-Wiedemann syndrome (SWS).

METHODS

A retrospective review of all cases of confirmed SWS during an 8-year period was conducted. Clinical and historical data and outcome of the pregnancies were noted. Fetal biometry, skeletal survey, amniotic fluid volume and associated anomalies were recorded. A sonographic algorithm was proposed to distinguish SWS from other bent bone disorders.

RESULTS

In total, there were 10 cases, six of which were diagnosed prenatally. The main prenatal features of SWS were mild-to-moderate micromelia and bowing of the lower limb bones, affecting the tibia more than the femur. There was relative sparing of fibula and upper limb bones, with normal scapulae and clavicles. Camptodactyly was the main associated anomaly. All fetuses developed growth restriction in the late second trimester with oligohydramnios in half of the cases. These features could appear late in pregnancy. Although the thoracic dimensions were normal in the majority of fetuses, respiratory insufficiency, as a result of myotonia, was a leading cause for mortality.

CONCLUSIONS

It is possible to diagnose SWS prenatally. SWS is associated with high mortality during the first year of life, and those who survive have high morbidity.

Differential secretion of the mutated protein is a major component affecting phenotypic severity in CRLF1-associated disorders

Crisponi syndrome (CS) and cold-induced sweating syndrome type 1 (CISS1) are disorders caused by mutations in CRLF1. The two syndromes share clinical characteristics, such as dysmorphic features, muscle contractions, scoliosis and cold-induced sweating, with CS patients showing a severe clinical course in infancy involving hyperthermia, associated with death in most cases in the first years of life. To evaluate a potential genotype/phenotype correlation and whether CS and CISS1 represent two allelic diseases or manifestations at different ages of the same disorder, we carried out a detailed clinical analysis of 19 patients carrying mutations in CRLF1. We studied the functional significance of the mutations found in CRLF1, providing evidence that phenotypic severity of the two disorders mainly depends on altered kinetics of secretion of the mutated CRLF1 protein. On the basis of these findings, we believe that the two syndromes, CS and CISS1, represent manifestations of the same disorder, with different degrees of severity. We suggest renaming the two genetic entities CS and CISS1 with the broader term of Sohar-Crisponi syndrome.

Mutations of a country: a mutation review of single gene disorders in the United Arab Emirates (UAE)

The United Arab Emirates inhabitants are ethnically diverse, with ancestries from Arabia, Persia, Baluchistan, and Africa. However, the majority of the current five million inhabitants are expatriates from the Asian subcontinent, Middle Eastern, African, and European countries. Consanguineous marriages within most UAE subpopulations are still the norm, leading to the formation of isolates and higher frequencies of recessive conditions. The UAE is ranked sixth in terms of prevalence of birth defects, with more than 270 genetic disorders reported in the national population. The UAE has high frequencies of blood disorders including thalassemias, sickle cell disease, and G6PD. In addition, certain genetic conditions are relatively common including cystic fibrosis, Joubert, and Meckel syndromes. Furthermore, numerous rare congenital malformations and metabolic disorders have been reported. We review the single gene disorders that have been studied at the molecular level in the UAE (which currently stand at 76) and compile the mutations found. Several novel (p.S2439fs) mutations have been reported including c.7317delA in NF1, c.5C>T (p.A2V) in DKC1, c.1766T>A (p.I589N) in TP63, and c.2117G>T (p.R706L) in VLDLR. We hope that this review will form the basis to establish a UAE mutations database and serve as a model for the collection of mutations of a country.

Stüve-Wiedemann syndrome: long-term follow-up and genetic heterogeneity

Stüve-Wiedemann syndrome (SWS, OMIM 601559) is a severe autosomal recessive condition caused by mutations in the leukemia inhibitory receptor (LIFR) gene. The main characteristic features are bowing of the long bones, neonatal respiratory distress, swallowing/sucking difficulties and dysautonomia symptoms including temperature instability often leading to death in the first years of life. We report here four patients with SWS who have survived beyond 36 months of age with no LIFR mutation. These patients have been compared with six unreported SWS survivors carrying null LIFR mutations. We provide evidence of clinical homogeneity of the syndrome in spite of the genetic heterogeneity.

The orthopaedic manifestations and management of children with Stüve-Wiedemann syndrome

Stüve-Wiedemann syndrome is an autosomal-recessive disorder characterised by bowing of the long bones, progressive scoliosis, episodic hyperthermia and respiratory distress, usually resulting in death in infancy. We reviewed five children with the condition who had been followed since birth and who survived into childhood with a mean age at operation of 7.8 years (5 to 14). There was marked functional impairment with dysplasia of the long bones and scoliosis. Treatment of the triplanar deformities of the femora involved the use of the Ilizarov technique with the Taylor Spatial Frame.

Walking was preserved and improved in three children along with considerable enhancement of the appearance. Early insertion of a growing rod to control the progressive juvenile scoliosis was beneficial. The use of the Taylor Spatial Frame is strongly recommended to address the major complex deformities of the lower limbs which are encountered in this condition and to prevent their progression.

Thermosensory and mechanosensory perception in human genetic disease

Peripheral sensory perception is established through an elaborate network of specialized neurons that mediate the translation of extraorganismal stimuli through the use of a broad array of receptors and downstream effector molecules. Studies of human genetic disorders, as well as mouse and other animal models, have identified some of the key molecules necessary for peripheral innervation and function. These findings have, in turn, yielded new insights into the developmental networks and homeostatic mechanisms necessary for the transformation of external stimuli into interpretable electrical impulses. In this review, we will summarize and discuss some of the genes/proteins implicated in two particular aspects of sensory perception, thermosensation and mechanosensation, highlighting pathways whose perturbation leads to both isolated and syndromic sensory deficits.

Abnormal oral-pharyngeal swallowing as cause of morbidity and early death in Stüve-Wiedemann syndrome

Stüve-Wiedemann syndrome (SWS) is an autosomal recessive bone dysplasia (OMIM #601559) characterized by bowing of long bones, camptodactyly, respiratory insufficiency, hyperthermic episodes, and neonatal death from hyperthermia or apnea. We describe two female siblings with SWS born from consanguineous Gypsy parents. For a further delineation of SWS, we report hypothyroidism and ectopic thyroid as part of its phenotypic spectrum. Molecular study in the leukemia inhibitory factor receptor (LIFR) gene (OMIM *151 443) demonstrated the presence of a mutation. We observed that in one of our patients, oropharyngeal disruption in the swallowing process caused repetitive aspiration pneumonias, life-threatening events, and finally death. We emphasize that these features represent dysautonomic manifestations of SWS, and are probably related to pharyngoesophageal dyskinesia due to abnormal autonomic control of the anterior rami of cervical roots C1-C5.

Congenital contractures and distinctive phenotypic features consistent with Stuve-Wiedmann syndrome in a male infant

Introduction

Expressionless face associated with multiple contractures has been encountered in an infant. There is a wide range of misconception regarding the categorization of children with multiple contractures among different pediatric disciplines. The fundamental element in categorizing children with multiple contractures is "the etiological understanding". In the absence of concomitant neuromuscular disease, however, the search for other reasons is mandatory. Our present paper signifies the necessity of proper interpretations of unusual clinical and radiographic features.

Case presentation

We describe a 3-months-old-infant presented with the phenotypic and the radiographic features consistent with the diagnosis of Stüve-Wiedemann syndrome. We report what might be the first clinical report of Stüve-Wiedemann syndrome from a consanguineous family in Austria.

Conclusion

Congenital limitations of the hips in a newborn infant raise the possibility of " Congenital Hip Dislocation". As congenital hip dislocation is a dysplastic process. Here further knowledge by the pediatrician and the orthopaedic surgeon is needed. Our present patient appears to constitute a distinct pathological entity consistent with Stüve-Wiedemann syndrome (SWS). Superti-Furga et al, and Cormier-Daire et al, also suggest that Stüve-Wiedemann syndrome and Schwartz-Jampel syndrome type 2 are allelic conditions. We wish to stress that, given the rarity of syndromic malformation complex, our impression is that it is more common than it is reported.

Long-term follow-up in Stuve-Wiedemann syndrome: a clinical report

Stuve-Wiedemann syndrome (SWS) is an autosomal recessively inherited disorder that is usually associated with high mortality in the neonatal period. Eleven cases have been published with prolonged survival, the oldest being 16 years. This phenotype is characterized by progressive skeletal anomalies including short stature, severe spinal deformities, bowing of the long bones, contractures and spontaneous fractures, and by neurological features that resemble dysautonomia. Here we report on the natural history of a Portuguese girl from birth till 12 years. The diagnosis was molecularly confirmed by the detection of a homozygous 4 bp deletion (167_170 del TAAC) in exon 3 of LIFR. We compare the findings in this patient to other patients with prolonged survival from the literature.

Radiological manifestations of the skeleton, lungs and brain in Stueve-Wiedemann syndrome

A total of 25 patients with the rare skeletal dysplasia Stueve-Wiedemann syndrome (SWS) have been evaluated during the last 11 years. Of all patients with clinical suspicion of SWS, skeletal and chest radiographs were obtained for classification of the underlying skeletal dysplasia. In one case, CT was carried out for the first time for further investigation of the midface hypoplasia. Typical conventional radiological findings and CT features were analysed and compared with published data. Early diagnosis of SWS was made by correlating radiological and clinical findings. Follow-up radiological examinations of the skeleton and of the chest were carried out in six children surviving infancy for evaluation of progression. Clinically, they suffered from progressive orthopaedic problems, recurrent aspiration pneumonia and recurrent episodes of hyperthermia, as well as cutaneous infections. Radiologically progressive bowing of the long tubular bones and progressive metaphyseal decalcification were present on follow-up skeletal radiographs. Skeletal abnormalities in SWS are so characteristic that an early post-partum diagnosis can be made by correlation of typical clinical and radiological findings. Few cases survive infancy. First, these patients face progressive orthopaedic problems and respiratory infections.

Crisponi syndrome is caused by mutations in the CRLF1 gene and is allelic to cold-induced sweating syndrome type 1

Crisponi syndrome is a severe autosomal recessive condition that is phenotypically characterized by abnormal, paroxysmal muscular contractions resembling neonatal tetanus, large face, broad nose, anteverted nares, camptodactyly, hyperthermia, and sudden death in most cases. We performed homozygosity mapping in five Sardinian and three Turkish families with Crisponi syndrome, using high-density single-nucleotide polymorphism arrays, and identified a critical region on chromosome 19p12-13.1. The most prominent candidate gene was CRLF1, recently found to be involved in the pathogenesis of cold-induced sweating syndrome type 1 (CISS1). CISS1 belongs to a group of conditions with overlapping phenotypes, also including cold-induced sweating syndrome type 2 and Stuve-Wiedemann syndrome. All these syndromes are caused by mutations of genes of the ciliary neurotrophic factor (CNTF)-receptor pathway. Here, we describe the identification of four different CRLF1 mutations in eight different Crisponi-affected families, including a missense mutation, a single-nucleotide insertion, and a nonsense and an insertion/deletion (indel) mutation, all segregating with the disease trait in the families. Comparison of the mutation spectra of Crisponi syndrome and CISS1 suggests that neither the type nor the location of the CRLF1 mutations points to a phenotype/genotype correlation that would account for the most severe phenotype in Crisponi syndrome. Other, still-unknown molecular factors may be responsible for the variable phenotypic expression of the CRLF1 mutations. We suggest that the syndromes can comprise a family of "CNTF-receptor-related disorders," of which Crisponi syndrome would be the newest member and allelic to CISS1.

Neonatal paroxysmal trismus and camptodactyly: the Crisponi syndrome

The Crisponi syndrome is an infrequently described syndrome characterized by extensive muscular contractions in the face after even minimal stimuli, hypertonia, camptodactyly, and typical facial features (chubby cheeks, broad nose with anteverted nares, and long philtrum). Most patients have died in the first months of life due to hyperthermia. The syndrome has been described in Italians only; the inheritance pattern is most probably autosomal recessive. Here we describe a 4-year-old boy of Portuguese descent with this entity. Polysomnography during a paroxysmal muscle contraction showed severe obstructive breathing pattern. The overall breathing pattern outside the attacks showed a bizarre mix of disorders of control of breathing with central apneas, hypopnea, obstructive apneas, and long periods of expiratory apneas while the boy was awake. The hyperexcitability disappeared in the course of the first year of life. With time it became clear that he was developmentally delayed. A short review is provided, and the resemblance with the Stuve-Wiedemann syndrome is stressed.

New insights in congenital bowing of the femora

The aim of this study is to review the clinical, radiological and molecular findings of the bent bone dysplasia group including Stüve-Wiedemann syndrome due to LIFR mutations, Compomelic dysplasia due to SOX9 mutations and Kyphomelic dysplasia with no known molecular bases.

Null leukemia inhibitory factor receptor (LIFR) mutations in Stuve-Wiedemann/Schwartz-Jampel type 2 syndrome

Stuve-Wiedemann syndrome (SWS) is a severe autosomal recessive condition characterized by bowing of the long bones, with cortical thickening, flared metaphyses with coarsened trabecular pattern, camptodactyly, respiratory distress, feeding difficulties, and hyperthermic episodes responsible for early lethality. Clinical overlap with Schwartz-Jampel type 2 syndrome (SJS2) has suggested that SWS and SJS2 could be allelic disorders. Through studying a series of 19 families with SWS/SJS2, we have mapped the disease gene to chromosome 5p13.1 at locus D5S418 (Zmax=10.66 at theta =0) and have identified null mutations in the leukemia inhibitory factor receptor (LIFR or gp190 chain) gene. A total of 14 distinct mutations were identified in the 19 families. An identical frameshift insertion (653_654insT) was identified in families from the United Arab Emirates, suggesting a founder effect in that region. It is interesting that 12/14 mutations predicted premature termination of translation. Functional studies indicated that these mutations alter the stability of LIFR messenger RNA transcripts, resulting in the absence of the LIFR protein and in the impairment of the JAK/STAT3 signaling pathway in patient cells. We conclude, therefore, that SWS and SJS2 represent a single clinically and genetically homogeneous condition due to null mutations in the LIFR gene on chromosome 5p13.