Expanding the Mutational Spectrum ofCRLF1in Crisponi/CISS1 Syndrome

PERCHING syndrome caused by variant gene KLHL7 in the first Iranian patient: a case report study

Introduction and importance

PERCHING syndrome is a condition that affects many parts of the body and is caused by genes passed down from both parents. People with this syndrome have delays in their development, unusual facial features, trouble eating and breathing, slow overall growth, weak muscles, and stiff joints.

Case presentation

The child at the age of 6 months suffered from developmental delay, delayed walking, speech delay, and hypotonia and was referred to the Neurologist. Also, he has an abnormal phenotype. Whole-exome sequencing (WES) revealed a missense variant in the KLHL7 gene at a highly conserved genomic Chr7: 23124718T>G; NM_018846:exon3:c.110T>G:p.Val37Gly.

Clinical discussion

One way to explain the difference in physical characteristics caused by recessive KLHL7 mutations might be related to the person's genetic makeup. However, the genes someone has do not always accurately determine their physical traits.

Conclusion

This report will help us learn more about the different traits and characteristics of Perching syndrome. The authors need to do more research on how proteins work and study more about patients with different characteristics to fully understand this.

Novel Mutations in CRLF1: Case Reports with Crisponi Syndrome

Crisponi syndrome (CS) is a rare autosomal recessive syndrome, characterized by episodic facial muscle contraction with trismus, abundant salivation along with intermittent hyperthermia, feeding difficulties, characteristic facial dysmorphism, and camptodactyly. Here the authors report two South Indian neonates with confirmed diagnosis of Crisponi syndrome, caused by novel pathogenic variants in cytokine receptor-like factor 1 (CRLF1) gene. The classical clinical findings observed in the present cases were feeding difficulty, facial dysmorphism, tachypnea, contractures, camptodactyly, opisthotonus, hyperthermia, poor growth, and facial muscle contraction resembling probable tetanus. The patients with variants identified in the signal peptide domain had typical spasms from day one of life as compared to the variants in other domains who had later onset at neonatal period. The authors provide a review of the cases described, so far, from India highlighting that no common variants attribute to this rare syndrome. Recognizing this syndrome is crucial to differentiate it from infective conditions and for effective genetic counseling. Though tetanus is almost eradicated in developing countries, genetic causes should be suspected in new cases.

Clinical and molecular genetic findings of Crisponi / cold-induced sweating syndrome (CS/CISS) spectrum in patients from Turkey

Crisponi / cold-induced sweating syndrome (CS/CISS) is a rare autosomal recessive disorder characterized by episodic hyperthermia, arthrogryposis, impaired feeding ability, and respiratory distress. The classic CS/CISS is mainly associated with CRLF1 and, rarely, CLCF1. PERCHING syndrome, previously known as CS/CISS type-3 associated with biallelic pathogenic variants in KLHL7, is notable for its few overlapping manifestations. This study presents genotype-phenotype relationships in CS/CISS-like spectrum associated with CRLF1 and KLHL7. Clinical findings of 19 patients from 14 families and four patients from three families were found in association with six different CRLF1 and three different KLHL7 variants, respectively. c.167 T > C and c.713delC of the CRLF1 gene and the c.642G > C of the KLHL7 were novel. The c.708_709delCCinsT allele of CRLF1 was identified in 10 families from the Mardin province of Turkey, underlining that an ancestral haplotype has become widespread. CRLF1-associated phenotypes revealed novel manifestations such as prenatal oligohydramnios, benign external hydrocephalus, previously unreported dysmorphic features emerging with advancing age, severe palmoplantar keratoderma and facial erythema, hypopigmented macules and streaks, and recurrent cardiac arrests. KLHL7 variants presented with glabellar nevus flammeus, blepharophimosis, microcephaly, thin corpus callosum, and cleft palate. Abnormalities of sweating, observed in one patient reported herein, is known to be very rare among KLHL7-related phenotypes. This article is protected by copyright. All rights reserved.

Influences of the IL-6 cytokine family on bone structure and function

The IL-6 family of cytokines comprises a large group of cytokines that all act via the formation of a signaling complex that includes the glycoprotein 130 (gp130) receptor. Despite this, many of these cytokines have unique roles that regulate the activity of bone forming osteoblasts, bone resorbing osteoclasts, bone-resident osteocytes, and cartilage cells (chondrocytes). These include specific functions in craniofacial development, longitudinal bone growth, and the maintenance of trabecular and cortical bone structure, and have been implicated in musculoskeletal pathologies such as craniosynostosis, osteoporosis, rheumatoid arthritis, osteoarthritis, and heterotopic ossifications. This review will work systematically through each member of this family and provide an overview and an update on the expression patterns and functions of each of these cytokines in the skeleton, as well as their negative feedback pathways, particularly suppressor of cytokine signaling 3 (SOCS3). The specific cytokines described are interleukin 6 (IL-6), interleukin 11 (IL-11), oncostatin M (OSM), leukemia inhibitory factor (LIF), cardiotrophin 1 (CT-1), ciliary neurotrophic factor (CNTF), cardiotrophin-like cytokine factor 1 (CLCF1), neuropoietin, humanin and interleukin 27 (IL-27).

Three new cases of Crisponi /cold induced sweating syndrome (CS/CISS1) in Turkish families

Crisponi syndrome/Cold Induced Sweating Syndrome 1 (CS/CISS1) is a rare, autosomal recessive, multisystemic disease. Hyperthermia attacks, abnormal contractions in the muscles of the face and oropharynx, respiratory distress, camptodactyly, and swallowing difficulty are the main features of the condition in the neonatal period. Patients experience cold-induced sweating attacks and progressive kyphoscoliosis in childhood and adolescence. Mutations in the cytokine receptor like factor 1 (CRLF1) gene causes the CISS1 (Cold- induced sweating syndrome type 1) disease (over 95% of patients). CRLF1 is located in the ciliary neurotrophic factor receptor (CNTFR) pathway, which plays an important role in development and maintenance of neurons in the nervous system. In this study three patients from Turkey, clinically and molecularly diagnosed with CS/CISS1, are presented. Hyperthermia, swallowing difficulty, camptodactyly and pursing of the lips were present in all patients, and foot deformity in one patient. In the first patient a homozygous nonsense mutation NM_004750.5: c.531G > A; p.(Trp177Ter) in the 4th exon was detected. In the second patient a homozygous nonsense mutation NM_004750.5: c.776C > A; p.(Ser259Ter) in the 5th exon was detected. The third patient was homozygous for a missense mutation NM_004750.5: c.935G > T; p.(Arg312Leu) in the 6th exon. Early diagnosis is very important in this syndrome since most patients die in the neonatal period. Therefore, physicians should be suspicious for this disease in patients with dysmorphic features, hyperthermia attacks, camptodactyly, pursing of lips while crying, and swallowing difficulty.

Everolimus in Invasive Malignant Renal Epithelioid Angiomyolipoma

Background

To evaluate the efficacy and safety of everolimus, a mTOR inhibitor, on invasive malignant renal epithelioid angiomyolipoma (EAML).

Materials and Methods

From Oct 2014 to May 2019, we collected data from seven patients with a definite (clinical and pathological) diagnosis of EAML received everolimus in our hospital. Targeted sequence capture array technique with next-generation of high throughput sequencing (NGS) were performed to detect mutations of TSC1/2 genes. All patients had received surgery and everolimus. The clinical efficacy and safety of the therapy were evaluated.

Results

Mutations of TSC1 and TSC2 were detected in two and three patients though targeted sequence capture array technique with NGS, respectively. Among seven patients, three had missense mutations, one had nonsense mutation, and one had the large fragment deletion mutation. Five patients accompanied with tuberous sclerosis complex (TSC) were identified. All patients were administered 10mg everolimus once daily, the treatment duration lasted for 3 to 28 months. The objective response was assessed 3 months later, five partial response, two stable disease (SD), the mean greatest tumor diameter of all patients decreased from 9.6 to 5.2cm. Six patients stayed SD and one patient died during follow up. Patients accompanying with TSC had better responses to everolimus compared with non-TSC.

Conclusion

The mTOR inhibitor can be an effective treatment for patients with invasive malignant renal EAML. Patients with TSC may benefit more from the therapy.

Whole-transcriptome sequencing of knee joint cartilage from osteoarthritis patients

Objectives

The aim of this study was to provide a comprehensive understanding of alterations in messenger RNAs (mRNAs), long noncoding RNAs (lncRNAs), and circular RNAs (circRNAs) in cartilage affected by osteoarthritis (OA).

Methods

The expression profiles of mRNAs, lncRNAs, and circRNAs in OA cartilage were assessed using whole-transcriptome sequencing. Bioinformatics analyses included prediction and reannotation of novel lncRNAs and circRNAs, their classification, and their placement into subgroups. Gene ontology and pathway analysis were performed to identify differentially expressed genes (DEGs), differentially expressed lncRNAs (DELs), and differentially expressed circRNAs (DECs). We focused on the overlap of DEGs and targets of DELs previously identified in seven high-throughput studies. The top ten DELs were verified by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) in articular chondrocytes, both in vitro and in vivo.

Results

In total, 739 mRNAs, 1152 lncRNAs, and 42 circRNAs were found to be differentially expressed in OA cartilage tissue. Among these, we identified 18 overlapping DEGs and targets of DELs, and the top ten DELs were screened by expression profile analysis as candidate OA-related genes. WISP2, ATF3, and CHI3L1 were significantly increased in both normal versus OA tissues and normal versus interleukin (IL)-1β-induced OA-like cell models, while ADAM12, PRELP, and ASPN were shown to be significantly decreased. Among the identified DELs, we observed higher expression of ENST00000453554 and MSTRG.99593.3, and lower expression of MSTRG.44186.2 and NONHSAT186094.1 in normal versus OA cells and tissues.

Conclusion

This study revealed expression patterns of coding and noncoding RNAs in OA cartilage, which added sets of genes and noncoding RNAs to the list of candidate diagnostic biomarkers and therapeutic agents for OA patients.

Cite this article: H. Li, H. H. Yang, Z. G. Sun, H. B. Tang, J. K. Min. Whole-transcriptome sequencing of knee joint cartilage from osteoarthritis patients. Bone Joint Res 2019;8:290–303. DOI: 10.1302/2046-3758.87.BJR-2018-0297.R1.

Two siblings with a novel nonsense variant provide further delineation of the spectrum of recessive KLHL7 diseases

Mutations in Kelch-like family member 7 (KLHL7) have recently been described as a cause of a constellation of clinical findings with descriptions of both a Crisponi syndrome (CS)/cold-induced sweating syndrome type 1 (CISS1)-like, as well as a Bohring-Opitz syndrome (BOS)-like presentation. Here we report two siblings of Guatelmalan descent with a novel homozygous nonsense mutation (p.Arg326*) in KLHL7. These children have multiple dysmorphic features and developmental delay. Interestingly, their clinical traits inconsistently overlap both the CS/CISS1-like and BOS-like phenotypes, and the siblings also have subtle differences from each other, suggesting that clinicians need to be aware of the degree of variability in the presentations of these patients. Still, there is enough in common between patients with recessive KLHL7 mutations to define a novel multisystem disease that features various neurodevelopmental, musculoskeletal, dysmorphic, and other unique components. This report adds to the clinical features and disease-associated variants of the newly-recognized spectrum of KLHL7 mutations, and offers a new description, PERCHING, for the resulting syndrome.

Mutations in CRLF1 cause familial achalasia

We here report a family from Libya with three siblings suffering from early onset achalasia born to healthy parents. We analyzed roughly 5000 disease-associated genes by a next-generation sequencing (NGS) approach. In the analyzed sibling we identified two heterozygous variants in CRLF1 (cytokine receptor-like factor 1). Mutations in CRLF1 have been associated with autosomal recessive Crisponi or cold-induced sweating syndrome type 1 (CS/CISS1), which among other symptoms also manifests with early onset feeding difficulties. Segregation analysis revealed compound heterozygosity for all affected siblings, while the unaffected mother carried the c.713dupC (p.Pro239Alafs*91) and the unaffected father carried the c.178T>A (p.Cys60Ser) variant. The c.713dupC variant has already been reported in affected CS/CISS1 patients, the pathogenicity of the c.178T>A variant was unclear. As reported previously for pathogenic CRLF1 variants, cytokine receptor-like factor 1 protein secretion from cells transfected with the c.178T>A variant was severely impaired. From these results we conclude that one should consider a CRLF1-related disorder in early onset achalasia even if other CS/CISS1 related symptoms are missing.

Bi-allelic Mutations in KLHL7 Cause a Crisponi/CISS1-like Phenotype Associated with Early-Onset Retinitis Pigmentosa

Crisponi syndrome (CS)/cold-induced sweating syndrome type 1 (CISS1) is a very rare autosomal-recessive disorder characterized by a complex phenotype with high neonatal lethality, associated with the following main clinical features: hyperthermia and feeding difficulties in the neonatal period, scoliosis, and paradoxical sweating induced by cold since early childhood. CS/CISS1 can be caused by mutations in cytokine receptor-like factor 1 (CRLF1). However, the physiopathological role of CRLF1 is still poorly understood. A subset of CS/CISS1 cases remain yet genetically unexplained after CRLF1 sequencing. In five of them, exome sequencing and targeted Sanger sequencing identified four homozygous disease-causing mutations in kelch-like family member 7 (KLHL7), affecting the Kelch domains of the protein. KLHL7 encodes a BTB-Kelch-related protein involved in the ubiquitination of target proteins for proteasome-mediated degradation. Mono-allelic substitutions in other domains of KLHL7 have been reported in three families affected by a late-onset form of autosomal-dominant retinitis pigmentosa. Retinitis pigmentosa was also present in two surviving children reported here carrying bi-allelic KLHL7 mutations. KLHL7 mutations are thus associated with a more severe phenotype in recessive than in dominant cases. Although these data further support the pathogenic role of KLHL7 mutations in a CS/CISS1-like phenotype, they do not explain all their clinical manifestations and highlight the high phenotypic heterogeneity associated with mutations in KLHL7.

Cytokine-Like Factor 1, an Essential Facilitator of Cardiotrophin-Like Cytokine:Ciliary Neurotrophic Factor Receptor α Signaling and sorLA-Mediated Turnover

Cardiotrophin-like cytokine:cytokine-like factor-1 (CLC:CLF-1) is a heterodimeric neurotropic cytokine that plays a crucial role during neuronal development. Mice lacking CLC:CLF-1 die soon after birth due to a suckling defect and show reduced numbers of motor neurons. Humans carrying mutations in CLC:CLF-1 develop similar disorders, known as Sohar-Crisponi or cold-induced sweating syndrome, and have a high risk of early death. It is well known that CLC binds the ciliary neurotrophic factor receptor α (CNTFRα) and is a prerequisite for signaling through the gp130/leukemia inhibitory factor receptor β (LIFRβ) heterodimer, whereas CLF-1 serves to promote the cellular release of CLC. However, the precise role of CLF-1 is unclear. Here, we report that CLF-1, based on its binding site for CLC and on two additional and independent sites for CNTFRα and sorLA, is a key player in CLC and CNTFRα signaling and turnover. The site for CNTFRα enables CLF-1 to promote CLC:CNTFRα complex formation and signaling. The second site establishes a link between the endocytic receptor sorLA and the tripartite CLC:CLF-1:CNTFRα complex and allows sorLA to downregulate the CNTFRα pool in stimulated cells. Finally, sorLA may bind and concentrate the tripartite soluble CLC:CLF-1:CNTFRα complex on cell membranes and thus facilitate its signaling through gp130/LIFRβ.

Crisponi/CISS1 syndrome: A case series

Crisponi/CISS1 syndrome (MIM#272430) is a rare autosomal recessive disease characterized by major feeding difficulties, camptodactyly, and anhidrosis in early childhood; and the subsequent development of paradoxical cold-induced sweating and scoliosis later in life. The syndrome is caused by biallelic mutations in CRLF1 or, much less commonly, CLCF1. Although genotype/phenotype correlation has been elusive, it has been suggested that the level of the mutant protein may correlate with the phenotypic severity. However, we show in this series of 12 patients from four families, all previously unpublished, that the homogeneity of the recently described c.983dupG (p.Ser328Argfs∗2) mutation in CRLF1 was associated with a highly variable degree of severity, and that the phenotype significantly overlaps with the recently described COG6-related anhidrosis syndrome (MIM#615328). Another fifth previously unpublished family is also described with a novel mutation in CRLF1, c.605delC (p.Ala202Valfs*32). In Saudi Arabia the prevalence of the syndrome is probably underestimated due to the difficulty in making the diagnosis considering the complex phenotype with typical neonatal and evolutive features.