Andrea Accogli

Serum-specific IgE and allergen immunotherapy in allergic children

AIM Allergen immunotherapy (AIT) is indicated in IgE-mediated respiratory allergy. Recently, it has been reported that serum-specific IgE (sIgE) levels >10 kU/l may predict AIT efficacy in adults with allergic rhinitis. The aim of the present preliminary study was to investigate whether this cut-off could also be associated with perception of effective AIT in children with allergic asthma and/or rhinitis due to house dust mites (HDM). METHODS A total of 31 allergic children (17 males; mean age of 12.5 years) with levels of serum sIgE to HDM >10 kU/l were evaluated. Eight allergic children (five males; mean age of 13.4 years) with levels of serum sIgE to HDM <10 kU/l were considered as control. All patients were treated with sublingual immunotherapy for 3 years with HDM allergen extract. Childrens perception of AIT efficacy was assessed by visual analog scale (VAS), considering both symptom severity and drug use. Responder patients were defined with >6 VAS. Severity of nasal symptoms was assessed by nasal VAS, and asthma control was evaluated by asthma control test; both were considered before and after AIT. RESULTS All children (but one) with sIgE >10 kU/l perceived AIT efficacy, whereas only one child with sIgE <10 kU/l perceived AIT benefit (p < 0.001). There was a strong relationship between perception of AIT efficacy by VAS and serum sIgE levels (r = 0.615; p < 0.001). Also, nasal VAS and asthma control tests significantly improved only in children with sIgE >10 kU/l (p < 0.001 for both). CONCLUSION Allergen-sIgE assessment before AIT prescription might represent a useful tool to individuate potential responders.

Severe presentation of WDR62 mutation: is there a role for modifying genetic factors?

Mutations in WDR62 are associated with primary microcephaly; however, they have been reported with wide phenotypic variability. We report on six individuals with novel WDR62 mutations who illustrate this variability and describe three in greater detail. Of the three, one lacks neuromotor development and has severe pachygyria on MRI, another has only delayed speech and motor development and moderate polymicrogyria, and the third has an intermediate phenotype. We observed a rare copy number change of unknown significance, a 17q25qter duplication, in the first severely affected individual. The 17q25 duplication included an interesting candidate gene, tubulin cofactor D (TBCD), crucial in microtubule assembly and disassembly. Sequencing of the non‐duplicated allele showed a TBCD missense mutation, predicted to cause a deleterious p.Phe1121Val substitution. Sequencing of a cohort of five patients with WDR62 mutations, including one with an identical mutation and different phenotype, plus 12 individuals with diagnosis of microlissencephaly and another individual with mild intellectual disability (ID) and a 17q25 duplication, did not reveal TBCD mutations. However, immunostaining with tubulin antibodies of cells from patients with both WDR62 and TBCD mutation showed abnormal tubulin network when compared to controls and cells with only the WDR62 mutation. Therefore, we propose that genetic factors contribute to modify the severity of the WDR62 phenotype and, although based on suggestive evidence, TBCD could function as one of such factors.

Interstitial 9p24.3 deletion involving only DOCK8 and KANK1 genes in two patients with non-overlapping phenotypic traits.

Chromosome 9p deletion represents a clinically and genetically heterogeneous condition characterized by a wide spectrum of phenotypic manifestations and a variable size of the deleted region. The deletion breakpoint occurs from 9p22 to 9p24 bands, and the large majority of cases have either terminal deletions or translocations involving another chromosome. Here we report on two patients with similar inherited interstitial 9p24.3 deletion involving only DOCK8 and KANK1 genes. Interestingly, the two patients showed non-overlapping phenotypic traits ranging from a complex phenotype in one to only trigonocephaly with minor dysmorphic features and hand anomalies in the other one. The factors underlying the phenotypic variation associated with seemingly identical genomic alterations are not entirely clear, even if smaller variants, single-nucleotide changes, and epigenetic or stochastic factors altering the expression of genes within functionally relevant pathways have been recently shown to contribute to phenotypic variation. We discuss the role of the two genes and propose possible explanations for the clinical heterogeneity of the phenotype of the two patients.

Rare deleterious variants in GRHL3 are associated with human spina bifida

Neural tube defects, including spina bifida, are among the most common birth defects caused by failure of neural tube closure during development. They have a complex etiology involving largely undetermined environmental and genetic factors. Previous studies in mouse models have implicated the transcription factor Grhl3 as an important factor in the pathogenesis of spina bifida. In the present study, we conducted a resequencing analysis of GRHL3 in a cohort of 233 familial and sporadic cases of spina bifida. We identified two novel truncating variants: one homozygous frameshift variant, p.Asp16Aspfs*10, in two affected siblings and one heterozygous intronic splicing variant, p.Ala318Glyfs*26. We also identified five missense variants, one of which was demonstrated to reduce the activation of gene targets in a luciferase reporter assay. With the previously identified p.Arg391Cys variant, eight variants were found in GRHL3. Comparison of the variant rate between our cohort and the ExAC database identified a significant enrichment of deleterious variants in GRHL3 in the whole gene and the transactivation region in spina bifida patients. These data provide strong evidence for a role of GRHL3 as a predisposing factor to spina bifida and will help dissect the complex etiology and pathogenic mechanisms of these malformations.

Beyond spinal muscular atrophy with lower extremity dominance: cerebellar hypoplasia associated with a novel mutation in BICD2

Beyond spinal muscular atrophy with lower extremity dominance: cerebellar hypoplasia associated with a novel mutation in BICD2 C. Fiorillo, F. Moro, G. Brisca, A. Accogli, F. Trucco, R. Trovato, M. Pedemonte, M. Severino, M. Catala, V. Capra, F. M. Santorelli, C. Bruno, A. Rossi and C. Minetti Molecular Medicine for Neurodegenerative and Neuromuscular Diseases Unit, IRCCS Stella Maris Foundation, Pisa; Center of Myology and Neurodegenerative Disorders, Istituto Giannina Gaslini, Genoa; Neurosurgery Unit, Istituto Giannina Gaslini, Genoa; Paediatric Neurology and Muscle Disease Unit, Istituto Giannina Gaslini, Genoa; Paediatric Neuroradiology Unit, Istituto Giannina Gaslini, Genoa, Italy; and F ed eration de Neurologie, Groupe Hospitalier Piti e-Salpêtri ere, and UMR 7622 UPMC and CNRS, Universit e Pierre et Marie Curie, Paris, France

Association of achondroplasia with sagittal synostosis and scaphocephaly in two patients, an underestimated condition?

We report on two patients with an unusual combination of achondroplasia and surgically treated sagittal synostosis and scaphocephaly. The most common achondroplasia mutation, p.Gly380Arg in fibroblast growth factor receptor 3 (FGFR3), was detected in both patients. Molecular genetic testing of FGFR1, FGFR2, FGFR3 and TWIST1 genes failed to detect any additional mutations. There are several reports of achondroplasia with associated craniosynostosis, but no other cases of scaphocephaly in children with achondroplasia have been described. Recently it has been demonstrated that FGFR3 mutations affect not only endochondral ossification but also membranous ossification, providing new explanations for the craniofacial hallmarks in achondroplasia. Our report suggests that the association of isolated scaphocephaly and other craniosynostoses with achondroplasia may be under recognized.

Food anaphylaxis in children: Peculiarity of characteristics.

Anaphylaxis is a ‘‘severe, life-threatening, generalised or systemic hypersensitivity reaction’’ as reported by the systematic review on its epidemiology in Europe. The diagnostic criteria are well defined and generally accepted. In general, anaphylaxis incidence ranges from 1.5 to 7.9 per 100,000 person-years, so 0.3% of the population may experience anaphylaxis in their lives. Food, drugs, stinging insects, and latex are the most common triggers. The updated World Allergy Organization Guidelines focus on its diagnosis and management. Infants and teenagers have increased vulnerability to anaphylaxis; comorbidity with severe or uncontrolled asthma, mastocytosis, and concurrent use of some medications increase the risk of severe or fatal anaphylaxis. Food is the most important trigger in childhood. Food anaphylaxis typically occurs after ingestion, more rarely after skin contact or inhalation. Clinical diagnosis is based on consideration of presenting signs and symptoms and on excluding other sudden-onset multisystemic diseases. Clinical history and serum allergen-specific IgE and/or skin prick test remain the cornerstone for diagnosing food allergy. In this regard, attempts have been made in order to define a level of IgE that might be a predictor of food allergy, as oral challenge must be avoided in patients with anaphylaxis. Recently, molecularbased allergy diagnostics, based on assessment of molecular components (recombinant or purified) of single allergens, improved the work-up, as it allows defining the profile of allergenic proteins involved in sensitisation and is useful to stratify the potential risk of inducing a severe allergic reaction. Fortunately, only few kinds of food, mainly including egg, milk, peanut, fish, soybean and wheat are usually the cause of anaphylaxis in children and adolescents. Their relevance depends on the age of patients and, of course, on dietetic habits, which are different in each country. In this regard, there are some studies that addressed this topic, also considering the different anaphylaxis symptoms. For these reasons, we report the clinical data of children and adolescents visited at Allergic Disease Center of the Istituto Giannina Gaslini (the most important paediatric hospital in Northern Italy) for anaphylaxis during the previous year, with the aim of: (i) defining clinical factors that might have an influence on the development of the disease; and (ii) describing the most relevant foods causing anaphylaxis. Diagnosis of food anaphylaxis was based on validated criteria, such as: (i) suggestive clinical history, (ii) allergen-specific IgE detection for suspected food, and (iii) symptoms consistent with sensitisation, i.e. the demonstration of a cause/effect dependence between ingestion of sensitising food allergen and occurrence of anaphylaxis clinical features (post hoc ergo propter hoc). Cardiovascular features were: hypotension, impairment of conscious state, pale and floppy presentation; respiratory features were: breathlessness, tongue or throat swelling, throat tightness, stridor, talking difficulty, wheezing, cough, and tachypnoea; gastrointestinal features were: vomiting, colic, and diarrhoea; skin features were: angio-oedema, urticaria, itching, and erythema. Globally, 75 patients were visited for anaphylaxis. Males (49, 65.3%) were more than females (Table 1). The mean

Exome sequencing of two Italian pedigrees with non-isolated Chiari malformation type I reveals candidate genes for cranio-facial development

Chiari malformation type I (CMI) is a congenital abnormality of the cranio-cerebral junction with an estimated incidence of 1 in 1280. CMI is characterized by underdevelopment of the occipital bone and posterior fossa (PF) and consequent cerebellar tonsil herniation. The presence for a genetic basis to CMI is supported by many lines of evidence. The cellular and molecular mechanisms leading to CM1 are poorly understood. The occipital bone formation is dependent on complex interactions between genes and molecules with pathologies resulting from disruption of this delicate process. Whole-exome sequencing of affected and not affected individuals from two Italian families with non-isolated CMI was undertaken. Single-nucleotide and short insertion–deletion variants were prioritized using KGGSeq knowledge-based platform. We identified three heterozygous missense variants: DKK1 c.121G>A (p.(A41T)) in the first family, and the LRP4 c.2552C>G (p.(T851R)) and BMP1 c.941G>A (p.(R314H)) in the second family. The variants were located at highly conserved residues, segregated with the disease, but they were not observed in 100 unaffected in-house controls. DKK1 encodes for a potent soluble WNT inhibitor that binds to LRP5 and LRP6, and is itself regulated by bone morphogenetic proteins (BMPs). DKK1 is required for embryonic head development and patterning. LRP4 is a novel osteoblast expressed receptor for DKK1 and a WNT and BMP 4 pathways integrator. Screening of DKK1 in a cohort of 65 CMI sporadic patients identified another missense variant, the c.359G>T (p.(R120L)), in two unrelated patients. These findings implicated the WNT signaling in the correct development of the cranial mesenchyme originating the PF.

A novel pathogenic MYH3 mutation in a child with Sheldon-Hall syndrome and vertebral fusions

Sheldon–Hall syndrome (SHS) is the most common of the distal arthrogryposes (DAs), a group of disorders characterized by congenital non‐progressive contractures. Patients with SHS present with contractures of the limbs and a distinctive triangular facies with prominent nasolabial folds. Calcaneovalgus deformity is frequent, as well as camptodactyly and ulnar deviation. Causative mutations in at least four different genes have been reported (MYH3, TNNI2, TPM2, and TNNT3). MYH3 plays a pivotal role in fetal muscle development and mutations in this gene are associated with Freeman–Sheldon syndrome, distal arthrogryposis 8 (DA8), and autosomal dominant spondylocarpotarsal synostosis. The last two disorders are characterized by skeletal abnormalities, in particular bony fusions. The observation that MYH3 may be mutated in these syndromes has suggested the involvement of this gene in bone development. We report the case of a boy with a novel pathogenic MYH3 mutation, presenting with the classical clinical features of SHS in association with unilateral carpal bone fusion and multiple vertebral fusions. This distinctive phenotype has never been reported in the literature so far and expands the phenotypic spectrum of SHS, endorsing the clinical variability of patients with MYH3‐related disorders. Our findings also support a role for MYH3 in both muscle and bone development, suggesting a phenotypic continuum in MYH3‐related disorders.

Moyamoya Vasculopathy in PHACE Syndrome: Six New Cases and Review of the Literature

BACKGROUND PHACE syndrome (Posterior fossa malformations, large cervicofacial infantile Hemangiomas, Arterial anomalies, aortic coarctation and Cardiac abnormalities, and Eye abnormalities) is a neurocutaneous disorder including posterior fossa malformations, hemangiomas, arterial lesions, cardiac defects, and eye abnormalities. PHACE arteriopathies may be progressive and recently have been categorized based on the risk of acute ischemic stroke, increasing attention to the potentially devastating consequences of cerebrovascular complications in this syndrome. In contrast, the natural history of arteriopathy in PHACE syndrome remains poorly understood. At the moment, there are no established surgical guidelines for high-risk vasculopathies, including quasi-moyamoya, in this syndrome. CASE DESCRIPTION We described the clinicoradiologic features of a small series of 6 patients with PHACE syndrome and quasi-moyamoya (5 female, age range 4 months to 12 years), focusing on the clinical course and surgical outcome of 3 children who were treated with encephaloduroarteriosynangiosis and encephalomyosynangiosis. In addition, we reviewed the radiologic, clinical, and surgical aspects of moyamoya vasculopathy in PHACE syndrome, providing information on 15 additional published cases. CONCLUSIONS Although the natural history of arteriopathy in PHACE syndrome is poorly understood, patients with high-risk vasculopathies, such as quasi-moyamoya disease, may benefit of revascularization by using encephaloduroarteriosynangiosis and encephalomyosynangiosis.