A Novel Missense Variant in the NKX2-1 Homeodomain Prevents Transcriptional Rescue by TAZ.

Background: Brain-lung-thyroid syndrome (BLTS) is caused by NKX2-1 haploinsufficiency, resulting in chorea/choreoathetosis, respiratory problems, and hypothyroidism. Genes interacting with NKX2-1 mutants influence its phenotypic variability. We report a novel NKX2-1 missense variant and the modifier function of TAZ/WWTR1 in BLTS. Methods: A child with BLTS underwent next-generation sequencing panel testing for thyroid disorders. His family was genotyped for NKX2-1 variants and screened for germline mosaicism. Mutant NKX2-1 was generated, and transactivation assays were performed on three NKX2-1 target gene promoters. DNA binding capacity and protein-protein interaction were analyzed. Results: The patient had severe BLTS and carried a novel missense variant c.632A>G (p.N211S) in NKX2-1, which failed to bind to specific DNA promoters, reducing their transactivation. TAZ cotransfection did not significantly increase transcription of these genes, although the variant retained its ability to bind to TAZ. Conclusions: We identify a novel pathogenic NKX2-1 variant that causes severe BLTS and is inherited through germline mosaicism. The mutant lacks DNA-binding capacity, impairing transactivation and suggesting that NKX2-1 binding to DNA is essential for TAZ-mediated transcriptional rescue.

Mechanical Thrombectomy for Acute Stroke in a 2-Month-Old Patient and Review of the Literature in Infancy.

Mechanical thrombectomy (MT) in pediatric stroke is supported by studies in adults, but there is controversy regarding younger patients. The main growth of intracranial vessels occurs up to 2 years when there can be more difficulties in MT.Description of the MT performed in a 2-month-old patient-the youngest infant published to date. We also review the literature on MT for stroke in infants.A 2-month-old patient presented with an awakening stroke secondary to an occlusion of the M1 segment of the left middle cerebral artery. A successful MT was performed with an aspiration device without clinically significant complications. An etiological study was completed, and neuroimaging showed focal cerebral arteriopathy. The 3-month outcome was excellent: the pediatric modified Rankin score was 0.Including this case, MT for acute stroke has been reported in only 10 infants. MT was successful in 90%, mostly using adult conventional stent retrievers. There were complications only in patients with mechanical circulatory support (MCS) devices; three patients died due to hemorrhagic transformation after MT and one patient died due to recurrent ischemic stroke.MT seems effective and safe in infants similarly to other pediatric ages. In children under 2 years of age, the presence of comorbidities requiring MCS devices is the main factor underlying poor prognosis.

Towards a Change in the Diagnostic Algorithm of Autism Spectrum Disorders: Evidence Supporting Whole Exome Sequencing as a First-Tier Test.

Autism spectrum disorder (ASD) is a prevalent and extremely heterogeneous neurodevelopmental disorder (NDD) with a strong genetic component. In recent years, the clinical relevance of de novo mutations to the aetiology of ASD has been demonstrated. Current guidelines recommend chromosomal microarray (CMA) and a FMR1 testing as first-tier tests, but there is increasing evidence that support the use of NGS for the diagnosis of NDDs. Specifically in ASD, it has not been extensively evaluated and, thus, we performed and compared the clinical utility of CMA, FMR1 testing, and/or whole exome sequencing (WES) in a cohort of 343 ASD patients. We achieved a global diagnostic rate of 12.8% (44/343), the majority of them being characterised by WES (33/44; 75%) compared to CMA (9/44; 20.4%) or FMR1 testing (2/44; 4.5%). Taking into account the age at which genetic testing was carried out, we identified a causal genetic alteration in 22.5% (37/164) of patients over 5 years old, but only in 3.9% (7/179) of patients under this age. Our data evidence the higher diagnostic power of WES compared to CMA in the study of ASD and support the implementation of WES as a first-tier test for the genetic diagnosis of this disorder, when there is no suspicion of fragile X syndrome.

Carey-Fineman-Ziter Syndrome: A MYMK-Related Myopathy Mimicking Brainstem Dysgenesis.

Carey-Fineman-Ziter syndrome is a congenital myopathy associated with mutations in the MYMK gene. It is clinically defined by the combination of hypotonia, Moebius-Robin sequence, facial anomalies and motor delay. Historically it was considered a brainstem dysgenesis syndrome. We provide detailed information of a Spanish boy with compound heterozygous variants in MYMK gene. A muscle biopsy performed as a toddler only disclosed minimal changes, but muscle MRI showed severe fatty infiltration of gluteus muscles and to a lesser extent in adductors magnus, sartorius and soleus muscles. Clinical course is fairly static, but the identification of new well characterized genetic cases will help to delineate the complete phenotype.

Rare Variants in 48 Genes Account for 42% of Cases of Epilepsy With or Without Neurodevelopmental Delay in 246 Pediatric Patients.

In order to characterize the genetic architecture of epilepsy in a pediatric population from the Iberian Peninsula (including the Canary Islands), we conducted targeted exome sequencing of 246 patients with infantile-onset seizures with or without neurodevelopmental delay. We detected 107 variants in 48 different genes, which were implicated in neuronal excitability, neurodevelopment, synaptic transmission, and metabolic pathways. In 104 cases (42%) we detected variant(s) that we classified as pathogenic or likely pathogenic. Of the 48 mutated genes, 32 were dominant, 8 recessive and 8 X-linked. Of the patients for whom family studies could be performed and in whom pathogenic variants were identified in dominant or X-linked genes, 82% carried de novo mutations. The involvement of small copy number variations (CNVs) is 9%. The use of progressively updated custom panels with high mean vertical coverage enabled establishment of a definitive diagnosis in a large proportion of cases (42%) and detection of CNVs (even duplications) with high fidelity. In 10.5% of patients we detected associations that are pending confirmation via functional and/or familial studies. Our findings had important consequences for the clinical management of the probands, since a large proportion of the cohort had been clinically misdiagnosed, and their families were subsequently able to avail of genetic counseling. In some cases, a more appropriate treatment was selected for the patient in question, or an inappropriate treatment discontinued. Our findings suggest the existence of modifier genes that may explain the incomplete penetrance of some epilepsy-related genes. We discuss possible reasons for non-diagnosis and future research directions. Further studies will be required to uncover the roles of structural variants, epimutations, and oligogenic inheritance in epilepsy, thereby providing a more complete molecular picture of this disease. In summary, given the broad phenotypic spectrum of most epilepsy-related genes, efficient genomic tools like the targeted exome sequencing panel described here are essential for early diagnosis and treatment, and should be implemented as first-tier diagnostic tools for children with epilepsy without a clear etiologic basis.

TAZ/WWTR1 Mediates the Pulmonary Effects of NKX2-1 Mutations in Brain-Lung-Thyroid Syndrome.

Context: Identification of a frameshift heterozygous mutation in the transcription factor NKX2-1 in a patient with brain-lung-thyroid syndrome (BLTS) and life-threatening lung emphysema. Objective: To study the genetic defect that causes this complex phenotype and dissect the molecular mechanism underlying this syndrome through functional analysis. Methods: Mutational study by DNA sequencing, generation of expression vectors, site-directed mutagenesis, protein-DNA-binding assays, luciferase reporter gene assays, confocal microscopy, coimmunoprecipitation, and bioinformatics analysis. Results: We identified a mutation [p.(Val75Glyfs*334)] in the amino-terminal domain of the NKX2-1 gene, which was functionally compared with a previously identified mutation [p.(Ala276Argfs*75)] in the carboxy-terminal domain in other patients with BLTS but without signs of respiratory distress. Both mutations showed similar protein expression profiles, subcellular localization, and deleterious effects on thyroid-, brain-, and lung-specific promoter activity. Coexpression of the coactivator TAZ/WWTR1 (transcriptional coactivator with PDZ-binding motif/WW domain-containing transcription regulator protein 1) restored the transactivation properties of p.(Ala276Argfs*75) but not p.(Val75Glyfs*334) NKX2-1 on a lung-specific promoter, although both NKX2-1 mutants could interact equally with TAZ/WWTR1. The retention of residual transcriptional activity in the carboxy-terminal mutant, which was absent in the amino-terminal mutant, allowed the functional rescue by TAZ/WWTR1. Conclusions: Our results support a mechanistic model involving TAZ/WWTR1 in the development of human congenital emphysema, suggesting that this protein could be a transcriptional modifier of the lung phenotype in BLTS.

LAMA2-related congenital muscular dystrophy complicated by West syndrome.

BACKGROUND: Mutations in the LAMA2 gene cause autosomal recessive laminin α2 related congenital muscular dystrophy. In patients with partial laminin α2 deficiency the phenotype is usually milder than in those with absent protein. Apart from the typical white matter abnormalities, there is an increased risk of cerebral complications such as epilepsy and mental retardation, despite a structurally normal brain. METHODS/RESULTS: We present a patient with primary partial laminin α2 deficiency due to a homozygous novel LAMA2 missense mutation who developed West syndrome in his first year of life. To our knowledge, this combination has not previously been reported. A 5 year-old boy exhibited global hypotonia with generalized muscle weakness from birth. At 8 months of age he presented infantile spasms and an EEG finding of hypsarrhythmia. Seizures were controlled in a few weeks with intramuscular synthetic ACTH, followed by valproic acid. Two years later antiepileptic medication was withdrawn. He achieved unsupported walking at the age of 4, but his cognitive status corresponded to a 2 year-old child. Epilepsy has not recurred and brain MRI showed the typical white matter abnormalities without associated neuronal migration defects. CONCLUSION: This report widens the clinical spectrum of cerebral manifestations related with mutations in LAMA2. The beginning of a severe epileptic encephalopathy modifies the natural history of the disease.

Clinical features and molecular characterization of a patient with muscle-eye-brain disease: a novel mutation in the POMGNT1 gene.

Muscle-eye-brain disease is a congenital muscular dystrophy characterized by structural brain and eye defects. Here, we describe a 12-year-old boy with partial agenesis of corpus callosum, ventriculomegaly, flattened brain stem, diffuse pachygyria, blindness, profound cognitive deficiencies, and generalized muscle weakness, yet without a clear dystrophic pattern on muscle biopsy. There was no glycosylation of α-dystroglycan and the genetic screening revealed a novel truncating mutation, c.1545delC (p.Tyr516Thrfs*21), and a previously identified missense mutation, c.1469G>A (p.Cys490Tyr), in the protein O-mannose beta-1,2-N-acetylglucosaminyltransferase 1 (POMGNT1) gene. These findings broaden the clinical spectrum of muscle-eye-brain disease to include pronounced hypotonia with severe brain and eye malformations, yet with mild histopathologic changes in the muscle specimen, despite the absence of glycosylated α-dystroglycan.

Assessment of interferon-related biomarkers in Aicardi-Goutières syndrome associated with mutations in TREX1, RNASEH2A, RNASEH2B, RNASEH2C, SAMHD1, and ADAR: a case-control study.

BACKGROUND: Aicardi-Goutières syndrome (AGS) is an inflammatory disorder caused by mutations in any of six genes (TREX1, RNASEH2A, RNASEH2B, RNASEH2C, SAMHD1, and ADAR). The disease is severe and effective treatments are urgently needed. We investigated the status of interferon-related biomarkers in patients with AGS with a view to future use in diagnosis and clinical trials. METHODS: In this case-control study, samples were collected prospectively from patients with mutation-proven AGS. The expression of six interferon-stimulated genes (ISGs) was measured by quantitative PCR, and the median fold change, when compared with the median of healthy controls, was used to create an interferon score for each patient. Scores higher than the mean of controls plus two SD (>2·466) were designated as positive. Additionally, we collated historical data for interferon activity, measured with a viral cytopathic assay, in CSF and serum from mutation-positive patients with AGS. We also undertook neutralisation assays of interferon activity in serum, and looked for the presence of autoantibodies against a panel of interferon proteins. FINDINGS: 74 (90%) of 82 patients had a positive interferon score (median 12·90, IQR 6·14-20·41) compared with two (7%) of 29 controls (median 0·93, IQR 0·57-1·30). Of the eight patients with a negative interferon score, seven had mutations in RNASEH2B (seven [27%] of all 26 patients with mutations in this gene). Repeat sampling in 16 patients was consistent for the presence or absence of an interferon signature on 39 of 41 occasions. Interferon activity (tested in 147 patients) was negatively correlated with age (CSF, r=-0·604; serum, r=-0·289), and was higher in CSF than in serum in 104 of 136 paired samples. Neutralisation assays suggested that measurable antiviral activity was related to interferon α production. We did not record significantly increased concentrations of autoantibodies to interferon subtypes in patients with AGS, or an association between the presence of autoantibodies and interferon score or serum interferon activity. INTERPRETATION: AGS is consistently associated with an interferon signature, which is apparently sustained over time and can thus be used to differentiate patients with AGS from controls. If future studies show that interferon status is a reactive biomarker, the measurement of an interferon score might prove useful in the assessment of treatment efficacy in clinical trials. FUNDING: European Union's Seventh Framework Programme; European Research Council.

Levetiracetam-induced reversible autistic regression.

Levetiracetam is a commonly prescribed antiepileptic drug, and is generally well tolerated, but can eventually cause behavioral disturbances. These disturbances seem more frequent in children and in patients with a previous psychiatric history. We report on reversible autistic regression induced by levetiracetam in a 6-year-old girl with spastic cerebral palsy, mild cognitive deficiency, and focal epilepsy. She was diagnosed with pervasive developmental disorder, and demonstrated mild to moderate impairment in pragmatic language and interactions with peers. After the introduction of levetiracetam, she developed stereotypies, and her social and communicative skills deteriorated severely. She also exhibited mood lability. When the medication was discontinued, a dramatic response occurred, with a complete resolution of new abnormal findings. Levetiracetam can provoke unusual behavioral adverse effects in certain patients who are biologically more vulnerable.

Cognitive and behavioral profile in females with epilepsy with PDCH19 mutation: two novel mutations and review of the literature.

Mutation in the protocadherin 19 (PCDH19) gene is an increasingly recognized cause of epilepsy in females. This disorder is frequently associated with mental retardation and psychiatric features. We describe two unrelated females with novel PCDH19 missense mutations. One was de novo, and the other was inherited from her unaffected father. Both had mild mental impairment but had remarkable behavioral problems. We reviewed the cognitive and behavioral profiles of previously reported PCDH19-positive cases. Intellectual disability appeared in 75% of patients, ranging from borderline to severe. More than half of the individuals presented behavioral disturbances, which could be divided into two different groups: autistic and non-autistic. The majority of patients with autism already had some degree of cognitive impairment. It appears that seizures tend to diminish or even stop in adolescence, so non-epileptic problems can become the most important and disabling issue in adult patients with PCDH19 mutation.

Dental management of oral self-mutilation in neurological patients: a case of congenital insensitivity to pain with anhidrosis.

Hereditary sensory and autonomic neuropathy type IV is a rare disease characterized by fever episodes, mental retardation of different intensity, recurrent episodes of fever secondary to anhidrosis, little or no perspiration and congenital insensitivity to pain. Oral self-mutilation is also a characteristic sign. In this article, we present the case of an infant, aged 22 months, who showed these clinical characteristics and was treated with a dental device to prevent the patient from injuring her tongue. This device consisted of two acrylic splints joined at the back in the posterior sector, it provided an anterior open bite and allowed the infant to breathe through her mouth. The lesions of the patient had improved after using the device but the patient died due to the medical problem. Neuropathies treatment is a great challenge for medical teams. Dentists should form part ot these teams because of the bucal implications that may appear. Different appliances can be designed in order to solve the special problems each case may present.

Syringomyelia secondary to posthemorrhagic hydrocephalus in a preterm infant.

Syringomyelia is often associated with hydrocephalus, especially in Chiari malformations, but it has never been described as a complication of posthemorrhagic hydrocephalus after preterm birth. We report on a premature infant who presented this exceptional association. He was born at 29 weeks of gestational age and suffered a grade 3 intraventricular hemorrhage. Progressive ventricular dilatation developed despite repeated lumbar punctures, and a ventricular reservoir had to be inserted for cerebrospinal fluid drainage. Two weeks later he presented a flaccid, areflexic paralysis of his left upper limb. Magnetic resonance imaging disclosed a remarkable tetraventricular hydrocephalus and a cervical hydrosyringomyelia expanding from the C(5) to T(1) segments. After shunt surgery, the cephalic perimeter stabilized, and the infant began to move his arm. On follow-up, a minimal paresis of the left hand persisted. This case highlights an unreported outcome of posthemorrhagic hydrocephalus. In this context, syringomyelia should be included in the differential diagnosis of any infant with who presents segmental signs of acute or progressive onset.

Macrophagic myofasciitis in childhood: a controversial entity.

Macrophagic myofasciitis is an unusual inflammatory myopathy, which has been almost exclusively reported in French adults with diffuse arthromyalgias and asthenia. It is characterized by an infiltrate of densely packed macrophages, with granular periodic-acid-Schiff positive content, on muscle biopsies at the site of vaccination. The presence of aluminum inclusions in these macrophages points to an inappropriate reaction to aluminum used as an adjuvant in some vaccines. Although in adults this entity is well defined, less than 15 cases have been reported in children. This study describes seven children, younger than 3 years of age, with typical lesions of macrophagic myofasciitis on quadriceps muscle biopsy. In five cases, biopsies were performed to exclude mitochondrial pathology. All the children developed hypotonia and motor or psychomotor delay, associated with others symptoms. Abnormal neuroimaging was evident in six cases. Spectrometry studies detected elevated levels of aluminum in muscle in three of four cases tested. Despite the wide use of vaccines in childhood, macrophagic myofasciitis was rarely observed in children and its characteristic histologic pattern could not be correlated with a distinctive clinical syndrome.

Clinical and histologic changes in the follow-up of a congenital myopathy.

A 19-year-old woman was born with congenital hypotonia, generalized weakness, and dysmorphic features. A muscle biopsy performed at age 18 months found that type I fibers were smaller and more numerous than type II fibers, and she was diagnosed with congenital fiber type disproportion. She grew up with moderate motor impairment, but after a stationary period her weakness progressed gradually and she developed a severe ophthalmoplegia. When she was 18 years old a second muscle biopsy still indicated the predominance of type I fibers but also the presence of central nuclei and strong oxidative enzyme activity in the center of most of the fibers; this was compatible with centronuclear myopathy. The diagnostic reconsideration raises questions about the pathogenesis of these diseases and the recognition of congenital fiber type disproportion as a distinct nosologic entity.

Vertebral artery fibromuscular dysplasia: an unusual cause of stroke in a 3-year-old child.

Fibromuscular dysplasia (FMD) is a systemic arteriopathy which tends to affect renal arteries followed by cervicocranial vessels. It can lead to cerebral infarction if cephalic arteries are involved. FMD is an unusual cause of stroke in childhood that generally affects the carotid area. Only four cases of vertebral FMD and subsequent stroke have been reported previously and we present the youngest patient of all. A healthy 3-year-old female was admitted to Hospital Doce de Octubre in Madrid, Spain with cerebellar infarction. Angiography disclosed basilar artery thrombosis and typical signs of FMD in both vertebral arteries. No other angiographic alteration was noted in the other vessels studied. Her phenotype and other investigations were unremarkable. The patient was treated with anti-aggregation therapy (aspirin) and the outcome was excellent. Investigation of the occurrence in childhood of this kind of arteriopathy may lead to clarification of its natural history and speculation about its unclear pathogenesis.

Symptomatic epidural lipomatosis of the spinal cord in a child: MR demonstration of spinal cord injury.

We report a case of symptomatic epidural lipomatosis in an 8-year-old girl with Cushing's syndrome secondary to longstanding high-dose steroid therapy for Crohn's disease. MR imaging of the spine revealed massive diffuse epidural fat compressing the entire spinal cord with T2 prolongation in the central gray matter of the cord suggesting ischemic myelopathy. This finding has not been previously demonstrated on imaging. A proposed mechanism underlying these findings is discussed.