Sizeable acquired subglottic cyst in a baby with Williams–Beuren syndrome: Association or coincidence?

We describe a case of an acquired subglottic cyst presented with persistent stridor and voice hoarsening in a baby diagnosed with Williams–Beuren syndrome that was born premature and required intubation during neonatal period. We also comment on whether this is a coincidence or there can be an association between impaired elastogenesis, a feature of patients with the syndrome and the formation of a subglottic cyst.     

A novel TNNI2 mutation causes Freeman–Sheldon syndrome in a Chinese family with an affected adult with only facial contractures

Distal arthrogryposes (DAs), a clinically and genetically heterogeneous group of disorders characterized by congenital contractures with predominant involvement of the hands and feet, can be classified into at least 12 different forms. These autosomal dominant disorders are of variable expressivity and reduced penetrance. Mutations in sarcomeric protein genes, including troponin I2 (TNNI2), troponin T3 (TNNT3), tropomyosin 2 (TPM2), embryonic myosin heavy chain 3 (MYH3), and myosin binding protein C1 (MYBPC1), have been identified in distal arthrogryposis type 1 (DA1, MIM 108120), type 2B (DA2B, MIM 601680) and type 2A (DA2A)/Freeman–Sheldon syndrome (FSS, MIM 193700). However, mutations causing FSS have only been reported in MYH3. Herein we describe a Chinese DA family whose members meet classical strict criteria for FSS, as well as one member of the family who has isolated facial features consistent with FSS. No disease-causing mutation was found in MYH3. Segregation of microsatellite markers flanking the TNNI2 and TNNT3 genes at 11p15.5 was compatible with linkage. Subsequent sequencing of TNNI2 revealed a novel mutation, c.A493T (p.I165F), located in the C-terminal region, which is critical for proper protein function. This mutation was found to cosegregate with the FSS phenotype in this family, and assessment using SIFT and PolyPhen-2 predicted a damaging effect. To the best of our knowledge, we report the first TNNI2 mutation in classical FSS and describe an atypical adult FSS case with only facial contractures resulting from somatic mosaicism. We infer that DA1, DA2B and FSS represent a phenotypic continuum of the same disorder and provide further genetic evidence for this hypothesis.     

Phenotype–genotype analysis in two Chinese families with Liddle syndrome

The families with Liddle syndrome show marked phenotypic variation in blood pressure, serum potassium and other clinical manifestations. Here we analyzed the correlation of genotype–phenotype in two Chinese families with Liddle syndrome. The sequence of C-terminus of SCNN1B and SCNN1G were screened in the two families with likely Liddle syndrome. In addition to hypertension and hypokalemia, one of the two pedigrees had sudden death in their family members, so the exons of 428 reported genes-related to cardiovascular diseases were screened as well in the family. A heterozygous βR566X nonsense mutation was found in the proband-1 in the first pedigree, and the proband’s sister and father. They showed mild phenotype with hypertension under control. In contrast, two of the four previous studies report that the mutation causes severe phenotype. A heterozygous βR597PfrX607 frameshift mutation was identified in the proband-2 in the second pedigree, showing malignant phenotype including resistant hypertension, hypokalemia, higher PRA and plasma angiotensin II levels. Both the proband-2 and the proband-2’s father had sudden death in their twenties, but no meaningful mutations were found by screening of the exons in 428 cardiovascular disease-related genes. However, the same mutation has been related to moderate phenotype in previous studies. Our results confirmed that the phenotypes of Liddle syndrome are varied significantly even with the same mutation. The mechanisms why the same mutation causes very different phenotype need to be explored because intervention of these modifiers may change the disease course and prognosis accordingly.     

Co-infection with two different Campylobacter jejuni strains in a patient with the Guillain-Barré syndrome

Campylobacter jejuni is the predominant cause of antecedent infection in Guillain-Barré syndrome (GBS) or Miller Fisher syndrome (MFS). C. jejuni probably triggers GBS or MFS through molecular mimicry between bacterial sialylated lipo-oligosaccharides (LOS) and gangliosides in peripheral nerve tissue. We investigated whether co-infections with multiple C. jejuni strains occur in GBS or MFS patients and we further characterized these strains. PFGE analysis of 83 C. jejuni isolates from single primary colonies from stool cultures of 13 patients with GBS or MFS revealed co-infection with two different strains in one patient (8%). We showed that only strain GB5.1 contained an LOS biosynthesis gene locus that is associated with neuropathy. The patient serum strongly reacted with the LOS of strain GB5.1 and not with the LOS of strain GB5.2. Mass spectrometry revealed that both strains expressed a non-sialylated outer core structure in their LOS. The patient serum contained anti-asialo-GM2 antibodies that cross-reacted with the LOS of strain GB5.1. This study demonstrates that co-infection with multiple C. jejuni strains occurs in GBS patients. Consequently, not all C. jejuni strains isolated from the faeces of a GBS patient are involved in the pathogenesis of GBS per se. Furthermore, this is the first report in which cross-reactivity of antibodies to asialo-GM2 and to the LOS of a C. jejuni strain from a GBS patient has been demonstrated. This finding suggests that molecular mimicry with non-sialylated structures may also be involved in the pathogenesis of GBS.     

Identification of a novel ZNF469 mutation in a large family with Ehlers–Danlos phenotype

Brittle cornea syndrome (BCS) is a genetically heterogeneous disorder characterized by extreme corneal fragility and thinning, which may lead to spontaneous or trauma-induced corneal rupture. BCS-1 and BCS-2 are caused by recessive mutations in ZNF469 and PRDM5, respectively. Both genes play a role in the regulatory pathway of corneal development and maintenance. We report a consanguineous family with five patients affected with the cardinal ocular features of BCS and significant musculoskeletal findings primarily in the form of joint hypermobility and severe kyphoscoliosis. The patients had thin velvety skin, hallux valgus, variable sensorineural hearing loss and arachnodactyly. Interestingly, one of the patients additionally had phenylketonuria and showed a milder ophthalmological and musculoskeletal phenotype than his affected siblings. The urinary pyridinoline and deoxypyridinoline concentrations and their ratios were mildly elevated indicating increased bone-collagen turnover. A novel homozygous 14 bp duplication in exon 2 of ZNF469 (c.8817_8830dup) was uncovered by direct sequencing. This family highlights the phenotypic overlap between BCS and Ehlers–Danlos syndrome.     

A novel mutation in exon 17 of the β-subunit of rod phosphodiesterase in two RP sisters of a consanguineous family

We report the molecular analysis of the subunit of the rod phosphodiesterase (PDEB) gene in a consanguineous autosomal recessive retinitis pigmentosa family that shows homozygosity for polymorphisms in the genomic region comprising this gene, and positive linkage between a PDEB marker and the diesease. The two affected sisters are homozygous for a T to G transversion in codon 699 of the PDEB gene, leading to the substitution of a leucine by an arginine residue. This change, enclosed in the catalytic domain of the PDEB, could result in a modification of the protein structure preventing the physiological hydrolysis of cGMP.     

Whole-exome sequencing reveals a recurrent mutation in the cathepsin C gene that causes Papillon–Lefevre syndrome in a Saudi family

Papillon–Lefevre syndrome (PALS) is a rare, autosomal recessive disorder characterized by periodontitis and hyperkeratosis over the palms and soles. Mutations in the cathepsin C gene (CTSC) have been recognized as the cause of PALS since the late 1990s. More than 75 mutations in CTSC have been identified, and phenotypic variability between different mutations has been described. Next generation sequencing is widely used for efficient molecular diagnostics in various clinical practices. Here we investigated a large consanguineous Saudi family with four affected and four unaffected individuals. All of the affected individuals suffered from hyperkeratosis over the palms and soles and had anomalies of both primary and secondary dentition. For molecular diagnostics, we combined whole-exome sequencing and genome-wide homozygosity mapping procedures, and identified a recurrent homozygous missense mutation (c.899G>A; p.Gly300Asp) in exon 7 of CTSC. Validation of all eight family members by Sanger sequencing confirmed co-segregation of the pathogenic variant (c.899G>A) with the disease phenotype. This is the first report of whole-exome sequencing performed for molecular diagnosis of PALS in Saudi Arabia. Our findings provide further insights into the genotype–phenotype correlation of CTSC pathogenicity in PALS.     

Do extrafloral nectaries present a defensive role against herbivores in two species of the family Bignoniaceae in a Neotropical savannas?

Despite the general belief that the interaction between extrafloral nectaries (EFNs) and ants is mutualistic, the defensive function of EFNs has been poorly documented in South American savannas. In this article, we evaluate the potential impact of EFNs (benefits and costs) on two species of plants from the dry areas of Central Brazil, Anemopaegma album and Anemopaegma scabriusculum (Bignoniaceae). In particular, we characterize the composition of substances secreted by the EFNs, test whether EFNs attract ants, and whether ants actually present a defensive role, leading to reduced herbivory and increased plant fitness. Histochemical analyses indicated that EFNs from both species of Anemopaegma secrete an exudate that is composed of sugars, and potentially lipids and proteins. Furthermore, EFNs from both species were shown to present a significant role in ant attraction. However, contrary to common expectations, ants were not found to protect plants against herbivore attack. No effect was found between ant visitation and flower or fruit production in A. album, while the presence of ants led to a significant decrease in flower production in A. scabriusculum. These results suggest that EFNs might present a similar cost and benefit in A. album, and a higher cost than benefit in A. scabriusculum. Since the ancestor of Anemopaegma occupied humid forests and already presented EFNs that were maintained in subsequent lineages that occupied savannas, we suggest that phylogenetic inertia might explain the presence of EFNs in the species of Anemopaegma in which EFNs lack a defensive function.     

Behavior of mercury in a soil–plant system as affected by inoculation with the arbuscular mycorrhizal fungus Glomus mosseae

Effects of inoculation with the arbuscular mycorrhizal (AM) fungus Glomus mosseae on the behavior of Hg in soil–plant system were investigated using an artificially contaminated soil at the concentrations of 0, 1.0, 2.0, and 4.0 mg Hg kg⁻¹. Mercury accumulation was lower in mycorrhizal roots than in nonmycorrhizal roots when Hg was added at the rates of 2.0 and 4.0 mg kg⁻¹, while no obvious difference in shoot Hg concentration was found between mycorrhizal and nonmycorrhizal treatments. Mycorrhizal inoculation significantly decreased the total and extractable Hg concentrations in soil as well as the ratio of extractable to total Hg in soil. Equilibration sorption of Hg by soil was investigated, and the results indicated that mycorrhizal treatment enhanced Hg sorption on soil. The uptake of Hg was lower by mycorrhizal roots than by nonmycorrhizal roots. These experiments provide further evidence for the role of mycorrhizal inoculation in increasing immobilization of Hg in soil and reducing the uptake of Hg by roots. Calculation on mass balance of Hg in soil suggests the presence of Hg loss from soil presumably through evaporation, and AM inoculation enhanced Hg evaporation. This was evidenced by a chamber study to detect the Hg evaporated from soil.     

Efficacy of pain control with topical lidocaine–epinephrine–tetracaine during laceration repair with tissue adhesive in children: a randomized controlled trial

Background:

Some children feel pain during wound closures using tissue adhesives. We sought to determine whether a topically applied analgesic solution of lidocaine–epinephrine–tetracaine would decrease pain during tissue adhesive repair.

Methods:

We conducted a randomized, placebo-controlled, blinded trial involving 221 children between the ages of 3 months and 17 years. Patients were enrolled between March 2011 and January 2012 when presenting to a tertiary-care pediatric emergency department with lacerations requiring closure with tissue adhesive. Patients received either lidocaine–epinephrine–tetracaine or placebo before undergoing wound closure. Our primary outcome was the pain rating of adhesive application according to the colour Visual Analogue Scale and the Faces Pain Scale — Revised. Our secondary outcomes were physician ratings of difficulty of wound closure and wound hemostasis, in addition to their prediction as to which treatment the patient had received.

Results:

Children who received the analgesic before wound closure reported less pain (median 0.5, interquartile range [IQR] 0.25–1.50) than those who received placebo (median 1.00, IQR 0.38–2.50) as rated using the colour Visual Analogue Scale (p = 0.01) and Faces Pain Scale – Revised (median 0.00, IQR 0.00–2.00, for analgesic v. median 2.00, IQR 0.00–4.00, for placebo, p < 0.01). Patients who received the analgesic were significantly more likely to report having or to appear to have a pain-free procedure (relative risk [RR] of pain 0.54, 95% confidence interval [CI] 0.37–0.80). Complete hemostasis of the wound was also more common among patients who received lidocaine–epinephrine–tetracaine than among those who received placebo (78.2% v. 59.3%, p = 0.008).

Interpretation:

Treating minor lacerations with lidocaine–epinephrine–tetracaine before wound closure with tissue adhesive reduced ratings of pain and increased the proportion of pain-free repairs among children aged 3 months to 17 years. This low-risk intervention may benefit children with lacerations requiring tissue adhesives instead of sutures. Trial registration: ClinicalTrials.gov, no. PR 6138378804.Minor laceration repair with tissue adhesive, or “skin glue,” is common in pediatrics. Although less painful than cutaneous sutures,¹ tissue adhesives polymerize through an exothermic reaction that may cause a burning, painful sensation. Pain is dependent on the specific formulation of the adhesive used and the method of application. One study of different tissue adhesives reported 23.8%–40.5% of participants feeling a “burning sensation”,² whereas another study reported “pain” in 17.6%–44.1% of children.³ The amounts of adhesive applied, method of application and individual patient characteristics can also influence the feeling of pain.^3,4 Because tissue adhesives polymerize on contact with moisture,^4,5 poor wound hemostasis has the potential to cause premature setting of the adhesive, leading to less efficient and more painful repairs.⁶Preventing procedural pain is a high priority in pediatric care.⁷ Inadequate analgesia for pediatric procedures may result in more complicated procedures, increased pain sensitivity with future procedures⁸ and increased fear and anxiety of medical experiences persisting into adulthood.⁹ A practical method to prevent pain during laceration repairs with tissue adhesive would have a substantial benefit for children.A topically applied analgesic solution containing lidocaine–epinephrine–tetracaine with vasoconstrictive properties provides safe and effective pain control during wound repair using sutures.¹⁰ A survey of pediatric emergency fellowship directors in the United States reported that 76% of respondents use this solution or a similar solution when suturing 3-cm chin lacerations in toddlers.¹¹ However, in a hospital chart review, this solution was used in less than half of tissue adhesive repairs, the remainder receiving either local injection of anesthetic or no pain control.¹² Reluctance to use lidocaine–epinephrine–tetracaine with tissue adhesive may be due to the perception that it is not worth the minimum 20-minute wait required for the analgesic to take effect¹³ or to a lack of awareness that tissue adhesives can cause pain.We sought to investigate whether preapplying lidocaine–epinephrine–tetracaine would decrease pain in children during minor laceration repair using tissue adhesive.     

Illustration of patient-reported outcome challenges and solutions in rare diseases: a systematic review in Cushing’s syndrome

Rare diseases are often not fully understood and efforts put in investigating it from patient perspective are usually met with challenges. We performed a systematic literature review (SLR) for the last 20?years in Cushing’s Syndrome (CS) to illustrate Patient-Reported Outcome (PRO) challenges, and show what solutions were found.PROs and other Clinical Outcome Assessment (COA) used with CS patients were reviewed in 36 studies. Two CS-specific Health Related Quality of Life (HRQL) measures were identified (i.e., CushingQoL, Tuebingen CD-25), as well as depression and neurocognitive measures. For CS-specific HRQL measures, the CushingQoL was the most widely used measure due in part to being the first CS-specific HRQL measure developed. With algorithms mapping the CushingQoL to both the SF-6D and EQ-5D, the CushingQoL could be used to facilitate economic modelling studies in the absence of a generic HRQL measure. While the CushingQoL offers only the global scale and two subscales compared to the six subscales of the Tuebingen CD-25, there is not yet adequate statistical validation data available for the Tuebingen CD-25 to suggest it can withstand the scrutiny of review by multiple stakeholders. Results of this review indicate that the inclusion of a measure of depressive symptoms, such as the BDI-II or similar measure, would be reasonable to include given the high level of comorbidity of depression among CS patients. A brief neurocognitive performance outcome, such as Trail Making tasks A and D or Digit Symbol, could help inform the interpretation of HRQL results. Neurocognitive differences may be an unassessed mediator of HRQL outcomes, partly accounting for the persistence of depressive symptoms and HRQL deficits despite treatment. Results suggest that HRQL improvements are possible within this population. These results are limited by small sample sizes and pre/post study design.CS showcases the difficulties encountered in measuring PROs in rare diseases. A solution for this specific case was developed in the form of dedicated PRO instruments, the CushingQOL and the Tuebingen-25. However, some aspects of CS may not be fully answered or not yet validated (e.g., depressive and cognitive symptoms). Further research needs to be done to address them.     

Fluorescence in situ hybridization reveals a break in the α-satellite DNA of chromosome 1 in a family with a balanced whole-arm translocation

We have characterized a whole-arm translocation involving chromosomes 1 and 19 by traditional cytogenetic methods and fluorescence in situ hybridization with chromosome-specific -satellite and whole-chromosome painting probes, and different satellite III DNA probes. We have identified a break in the -satellite DNA region of chromosome 1, with division of this material into two a-satellite DNA blocks. This leaves one translocation chromosome with truncated -satellite DNA from chromosome 1 and the other trranslocation chromosome with all the -satellite DNA from chromosome 19 and truncated -satellite DNA from chromosome 1. We speculate whether the recombination event observed has taken place in tetraplex structures of satellite III DNA interspersed between -satellite DNA.     

Study of a family with a fragile site of the X chromosome at Xq27–28 without mental retardation

Summary The fragile site Xq27–28 was observed in several individuals of a large family. It is expressed at a high frequency among the carrier females, even as adults, and in one clinically normal male. None of the members of this family is affected with the mental retardation normally linked to this fragile site. Cytogenetic and flanking DNA marker polymorphism studies suggest a possible dissociation between the fragile site and clinical expression of the disease.     

Amplification of the COL2A1 3′ variable region used for segregation analysis in a family with the Stickler syndrome

Summary Amplification of a variable region 3 to the human type II collagen gene (COL2A1) has permitted segregation analysis in a three generation Stickler syndrome pedigree. This family had previously proved uninformative for the known restriction fragment length dimorphisms. Amplification of the variable region revealed five distinguishable alleles, of which three were segregating in this family. The lod score in favour of linkage was 2.86 at zero recombination.     

A 5-kb imprinting center deletion in a family with Angelman syndrome reduces the shortest region of deletion overlap to 880 bp

Imprinting on human chromosome 15q11-q13 is controlled by a bipartite imprinting center (IC) that maps to the SNRPN locus. Deletions of the IC result in an imprinting defect and Prader-Willi syndrome or Angelman syndrome (AS). We have now identified a 5-kb IC deletion in an English AS patient (AS-LO); this represents the smallest microdeletion found in AS and narrows down the shortest region of deletion overlap to 880 bp.     

Identification and characterization of a HEPN-MNT family type II toxin–antitoxin in Shewanella oneidensis

Toxin–antitoxin (TA) systems are prevalent in bacteria and archaea. However, related studies in the ecologically and bioelectrochemically important strain Shewanella oneidensis are limited. Here, we show that SO_3166, a member of the higher eukaryotes and prokaryotes nucleotide-binding (HEPN) superfamily, strongly inhibited cell growth in S. oneidensis and Escherichia coli. SO_3165, a putative minimal nucleotidyltransferase (MNT), neutralized the toxicity of SO_3166. Gene SO_3165 lies upstream of SO_3166, and they are co-transcribed. Moreover, the SO_3165 and SO_3166 proteins interact with each other directly in vivo, and antitoxin SO_3165 bound to the promoter of the TA operon and repressed its activity. Finally, the conserved Rx4-6H domain in HEPN family was identified in SO_3166. Mutating either the R or H abolished SO_3166 toxicity, confirming that Rx4-6H domain is critical for SO_3166 activity. Taken together, these results demonstrate that SO_3166 and SO_3165 in S. oneidensis form a typical type II TA pair. This TA pair plays a critical role in regulating bacterial functions because its disruption led to impaired cell motility in S. oneidensis. Thus, we demonstrated for the first time that HEPN-MNT can function as a TA system, thereby providing important insights into the understanding of the function and regulation of HEPNs and MNTs in prokaryotes.