Giovanna Stefania Colafati

Understanding pyrroline-5-carboxylate synthetase deficiency: clinical, molecular, functional, and expression studies, structure-based analysis, and novel therapy with arginine

AbstractΔ1-Pyrroline-5-carboxylate synthetase (P5CS) catalyzes the first two steps of ornithine/proline biosynthesis. P5CS deficiency has been reported in three families, with patients presenting with cutis/joint laxity, cataracts, and neurodevelopmental delay. Only one family exhibited metabolic changes consistent with P5CS deficiency (low proline/ornithine/citrulline/arginine; fasting hyperammonemia). Here we report a new P5CS-deficient patient presenting the complete clinical/metabolic phenotype and carrying p.G93R and p.T299I substitutions in the γ-glutamyl kinase (γGK) component of P5CS. The effects of these substitutions are (1) tested in mutagenesis/functional studies with E.coli γGK, (2) rationalized by structural modelling, and (3) reflected in decreased P5CS protein in patient fibroblasts (shown by immunofluorescence). Using optical/electron microscopy on skin biopsy, we show collagen/elastin fiber alterations that may contribute to connective tissue laxity and are compatible with our angio-MRI finding of kinky brain vessels in the patient. MR spectroscopy revealed decreased brain creatine, which normalized after sustained arginine supplementation, with improvement of neurodevelopmental and metabolic parameters, suggesting a pathogenic role of brain creatine decrease and the value of arginine therapy. Morphological and functional studies of fibroblast mitochondria show that P5CS deficiency is not associated with the mitochondrial alterations observed in Δ1-pyrroline-5-carboxylate reductase deficiency (another proline biosynthesis defect presenting cutis laxa and neurological alterations).

Intraventricular nerve growth factor infusion: a possible treatment for neurological deficits following hypoxic-ischemic brain injury in infants

Abstract Objective and importance: Hypoxic–ischemic brain injuries in childhood are associated with poor neurological outcome. Unfortunately, no new therapeutic approaches have been proposed. Recently, animal studies show that nerve growth factor (NGF) can reduce neurological deficits following hypoxic–ischemic brain injuries. The objective of this study is to demonstrate the therapeutic effects of intraventricular NGF infusion in severe post-ischemic damage. Clinical presentation: Two infants, aged 9 and 8 months, with hypoxic–ischemic brain damage, secondary to prolonged cardiorespiratory arrest and stabilized after the conventional treatment, were treated with intraventricular NGF infusion. Before the therapy both infants were comatose with asymmetrical tetraparesis; their Glasgow Coma Scale (GCS) was 4 and 5, respectively. One month after the treatment, their GCS was 8 and 9, respectively. EEG examinations performed after the NGF infusion showed an increased alpha/theta ratio. MRI showed a reduction of malacic areas in the brain. A SPECT study, performed only in one infant, demonstrated that the NGF treatment resulted in an improvement of regional cerebral perfusion in right temporal and occipital cortices. Intervention: The drug utilized was 2.5S NGF purified and lyophilized from male mouse submaxillary glands. NGF infusion was started about 30 days after the hypoxic–ischemic brain injury. 0.1 mg NGF was administered via the external drainage catheter into the right cerebral ventricle once a day for 10 days consecutively. Conclusion: Our observations are interesting, but further studies are necessary to confirm the effects of NGF in hypoxic-ischemic brain injuries in infants.

Description of a novel TUBA1A mutation in Arg-390 associated with asymmetrical polymicrogyria and mid-hindbrain dysgenesis

Mutations of TUBA1A gene were first identified as causing a distinctive neuroradiologic phenotype characterized by cortical abnormalities ranging from classical lissencephaly to perisylvian pachygyria with dysgenetic corpus callosum, brainstem and cerebellum. We describe the clinical and neuroradiological features of a 3 years old girl carrying a novel missense TUBA1A mutation associated with asymmetrical polymicrogyria and provide structural data about the mutation. Our case confirm that the spectrum of tubulin-related cortical phenotypes is wide and that the screening of these genes should be implemented in patients with mid-hindbrain dysgenesis, partial of complete corpus callosum agenesis and varying degrees of cortical abnormalities.

Large cell anaplastic medulloblastoma metastatic to the scalp: tumor and derived stem-like cells features.

BackgroundExtraneural metastases (ENM) rarely occur in medulloblastoma (MBL) patients and only few cases of subcutaneous localizations have been described. ENM indicate an aggressive disease associated with a worse prognosis. The characterization of metastatic tumours might be useful to understand their pathogenesis and to identify the most appropriate therapeutic strategies.Case presentationWe present the case of a child with Large Cell Anaplastic (LC/A) MBL, who developed multiple subcutaneous metastases in the scalp area after a ventriculo-peritoneal shunting procedure. The disease rapidly progressed and the child died despite chemotherapy and primary tumour surgical debulking.We molecularly classified the tumour as a group 3 MBL; in addition, we derived stem-like cells (SLC) from a metastatic lesion. Primary tumour, metastases and SLC were further analysed, particularly focusing on features linked to the cutaneous dissemination. Indeed, molecules involved in angiogenesis, cell invasion and epidermal growth factor signalling resulted highly expressed.ConclusionsThe present report describes a very rare case of subcutaneous metastatic MBL. The tumour, metastases and SLC have been clinically, pathologically and molecularly characterized. Our case is an example of multidisciplinary approach aiming to characterize MBL aggressive behaviour.

Characterization of medulloblastoma in Fanconi Anemia: a novel mutation in the BRCA2 gene and SHH molecular subgroup

AbstractFanconi Anemia (FA) is an inherited disorder characterized by the variable presence of multiple congenital somatic abnormalities, bone marrow failure and cancer susceptibility. Medulloblastoma (MB) has been described only in few cases of FA with biallelic inactivation in the tumor suppressor gene BRCA2/FANCD1 or its associated gene PALB2/FANCN. We report the case of a patient affected by Fanconi Anemia with Wilms tumor and unusual presentation of two medulloblastomas (MB1 and MB2). We identified a new pathogenetic germline BRCA2 mutation: c.2944_2944delA. Molecular analysis of MBs allowed us to define new features of MB in FA. MBs were found to belong to the Sonic Hedgehog (SHH) molecular subgroup with some differences between MB1 and MB2. We highlighted that MB in FA could share molecular aspects and hemispheric localization with sporadic adult SHH-MB. Our report provides new findings that shed new light on the genetic and molecular pathogenesis of MB in FA patients with implications in the disease management.

Hemimegalencephaly Associated with Congenital Infiltrating Lipomatosis of the Face: A Case Report

Hemimegalencephaly (HME) is a rare congenital malformation of the brain, grossly characterized by enlargement and overdevelopment of one cerebral hemisphere. We describe a 16-month-old patient with facial asymmetry caused by congenital infiltrating lipomatosis of the face (CILF) associated with ipsilateral HME. Although HME has been described as part of different syndromic diseases, the association of HME with CILF has been rarely reported. Our case and literature review suggest that when the diagnosis of CILF is suspected or established, the possible presence of associated HME has to be considered and a magnetic resonance imaging (MRI) must be performed even in absence of neurological features, not always present in early stages. MRI also demonstrates the involvement of intracranial structures outside the affected cerebral hemisphere, such as brain stem, cerebellum, cranial nerves, and blood vessels. In our patient, computed tomography of the brain provided detailed information on osseous hypertrophy and skull-base foramina enlargement.

Behavioral disorders as unusual presentation of pediatric extraventricular neurocytoma: report on two cases and review of the literature

BackgroundExtraventricular neurocytomas (EVNs) are rare parenchymal brain tumors, distinct from central neurocytomas that are typically located within the supratentorial ventricular system. Seizures and headache represent the most common symptoms of extraventricular neurocytomas in the cerebral hemisphere both in adult and pediatric population.Case presentationWe describe two cases of pediatric EVN with clinical onset characterized by behavioral and attention deficit/ hyperactivity disorders. The association between behavioral/attention disorders in childhood and the presence of a frontal neurocytoma has never been described before. Furthermore, inappropriate levels of inattention, hyperactivity and impulsivity are common among the neurobehavioral and developmental disorders in childhood. We reviewed 43 pediatric cases of extraventricular neurocytoma included in the PubMed database and their clinical presentation, and we never found this unusual relationship.ConclusionIn childhood, the attention/hyperactivity disorders seem to be often over-diagnosed. When these deficits are more subtle and do not well-fit in a specific neurocognitive disorder, the clinicians should have a suspicion that they might mask the clinical features of a frontal lesion. This paper is focused on the clinical presentation of the extraventricular neurocytoma and the possible organic etiology of an attention and hyperactivity deficit.

Muscle MRI of classic infantile pompe patients: Fatty substitution and edema-like changes

The aim of this study was to evaluate the muscle MRI pattern of 9 patients (median age: 6.5 ± 2.74 years) affected by classic infantile‐onset Pompe disease who were treated with enzyme replacement therapy.

Metastatic Group 3 Medulloblastoma in a Patient With Tuberous Sclerosis Complex: Case Description and Molecular Characterization of the Tumor

Medulloblastoma is the most common pediatric brain tumor. We describe a child with tuberous sclerosis complex that developed a Group 3, myc overexpressed, metastatic medulloblastoma (MB). Considering the high risk of treatment‐induced malignancies, a tailored therapy, omitting radiation, was given. Based on the evidence of mammalian target of rapamycin mTORC, mTOR Complex; RAS, Rat sarcoma; RAF, rapidly accelerated fibrosarcoma (mTOR) pathway activation in the tumor, targeted therapy was applied resulting in complete remission of disease. Although the PI3K/AKT/mTOR signaling pathway plays a role in MB, we did not find TSC1/TSC2 (TSC, tuberous sclerosis complex) mutation in our patient. We speculate that a different pathway resulting in mTOR activation is the basis of both TSC and MB in this child; H&E, haematoxilin and eosin; Gd, gadolinium.

Robot-Assisted Stereotactic Biopsy of Diffuse Intrinsic Pontine Glioma: A Single-Center Experience

BACKGROUND Diffuse intrinsic pontine glioma (DIPG) is a childhood tumor with a dismal prognosis. Emerging molecular signatures have paved the way for stereotactic biopsy in selected centers. We present our experience in DIPG stereotactic needle biopsy using the Robotic Stereotactic-Assisted system (ROSA) in a series of consecutive pediatric patients. METHODS All stereotactic biopsy procedures for DIPG performed during the last year at our institution were considered. All procedures were carried out using the ROSA surgical assistant through a precoronary approach. All children underwent a postoperative computed tomography scan to document possible surgical complications and confirm the site of biopsy. Postoperative clinical changes were recorded to test morbidity of the procedure. RESULTS In the last year, we performed 7 pontine needle biopsies. Specimens were diagnostic and useful for molecular analysis in all cases. No surgical complications were observed. One child showed a transient neurologic worsening related to the biopsy that resolved within 2 weeks. The combination of the precoronary approach and use of the stereotactic ROSA system allowed single-session surgeries in all cases. CONCLUSIONS Pontine biopsy for DIPG is a safe procedure in selected centers. The advantages of the single-session procedure we described might be of particular interest in the pediatric setting.