Cortical malformations and COL4A1 mutation: Three new cases.

AIM: The COL4A1 gene (13q34) encodes the α1 chain of type IV collagen, a crucial component of the basal membrane. COL4A1 mutations have been identified as a cause of a multisystem disease. Brain MRI in COL4A1-mutated patients typically shows vascular abnormalities and white matter lesions. Cortical malformations (specifically schizencephaly) have also recently been described in these patients, suggesting that these, too, could be part of the phenotypic spectrum of COL4A1 mutations. The aim of our work was to retrospectively evaluate COL4A1-mutated subjects diagnosed at our centers in order to assess the frequency and define the type of cortical malformations encountered in these individuals. METHOD: We retrospectively reviewed MRI data of 18 carriers of COL4A1 mutations diagnosed in our centers between 2010 and 2016. RESULTS: We identified polymicrogyria in two patients, and schizencephaly in the mother of a further patient. INTERPRETATION: Our findings confirm that cortical malformations should be considered to fall within the phenotypic spectrum of COL4A1 mutations and show that not only schizencephaly but also polymicrogyria can also be found in mutated individuals. Although further studies are needed to clarify the underlying pathogenetic mechanism, independently of this, the timing of the brain damage could be the crucial factor determining the type of lesion.

Inhibition of the de-myelinating properties of Aicardi-Goutières syndrome lymphocytes by cathepsin D silencing.

Molecular mechanisms relating interferon-alpha (IFN-alpha) to brain damage have recently been identified in a microarray analysis of cerebrospinal fluid lymphocytes from patients with Aicardi-Goutières Syndrome (AGS). These findings demonstrate that the inhibition of angiogenesis and the activation of neurotoxic lymphocytes are the major pathogenic mechanisms involved in the brain damage consequent to elevated interferon-alpha levels. Our previous study demonstrated that cathepsin D, a lysosomal aspartyl endopeptidase, is the primary mediator of the neurotoxicity exerted by AGS lymphocytes. Cathepsin D is a potent pro-apoptotic, neurotoxic, and demyelinating protease if it is not properly inhibited by the activities of leukocystatins. In central nervous system white matter, demyelination results from cathepsin over-expression when not balanced by the expression of its inhibitors. In the present study, we used RNA interference to inhibit cathepsin D expression in AGS lymphocytes with the aim of decreasing the neurotoxicity of these cells. Peripheral blood lymphocytes collected from an AGS patient were immortalized and co-cultured with astrocytes in the presence of interferon alpha with or without cathepsin D RNA interference probes. Cathepsin D expression was measured by qPCR, and neurotoxicity was evaluated by microscopy. RNA interference inhibited cathepsin D over-production by 2.6-fold (P<0.01) in AGS lymphocytes cultured in the presence of interferon alpha. AGS lymphocytes treated using RNA interference exhibited a decreased ability to induce neurotoxicity in astrocytes. Such neurotoxicity results in the inhibition of astrocyte growth and the inhibition of the ability of astrocytes to construct web-like aggregates. These results suggest a new strategy for repairing AGS lymphocytes in vitro by inhibiting their ability to induce astrocyte damage and leukodystrophy.

Inhibition of neuroblastoma cell growth by TREX1-mutated human lymphocytes.

T lymphocytes play a major role in counteracting cancer occurrence and development. Immune therapies against cancer are focused on eliciting a cytotoxic T cell response. This anticancer activity is related to a variety of mechanisms including the activation of cytokines and proapoptotic mediators. Interferon α is an established inhibitor of cancer cell growth. A clinical situation involving the coexistence of high interferon α levels and lymphocyte activation is the Aicardi-Goutières syndrome, a progressive encephalopathy arising usually during the first year of life characterized by intracranial basal ganglia calcifications, leukodystrophy and microcephaly. Aicardi-Goutières syndrome 1 mutation silences the TREX1 gene, a major endogenous nuclease. The in vitro study presented herein evaluates the efficacy of the TREX1 mutation in potentiating the anticancer properties of T cells. A TREX1-mutated lymphocyte cell line was derived from an Aicardi-Goutières syndrome patient and co-cultured with neuroblastoma cells and vascular endothelial cells in the presence of interferon α. TREX1-mutated lymphocytes exerted marked inhibitory action on neuroblastoma cell growth. Cathepsin D was recognized by qPCR as the main mediator produced by TREX1-mutated lymphocytes involved in the inhibition of neuroblastoma cell growth. These effects were enhanced in the presence of interferon α. Similar inhibitory effects in cell growth were exerted by TREX1-mutated lymphocytes towards vascular endothelial cell angiogenesis as evaluated on Matrigel. The results obtained provide evidence that mutations of the TREX1 gene increase the capability of T-lymphocytes to inhibit growth of neoplastic neuronal cells and related angiogenesis.

COL4A1 mutations associated with a characteristic pattern of intracranial calcification.

Intracranial calcification (ICC) is a relatively common radiological finding in children undergoing investigation for neurological disorders. Many causes are recognised, and ICC is often regarded as a non-specific sign.From an ongoing study of ICC, we identified 5 patients with characteristic radiological features, in whom a mutation in the COL4A1 gene was found.All patients had CT and MR imaging. MR images demonstrated features of periventricular leukomalacia with irregular dilatation of the lateral ventricles with or without porencephaly, loss of hemispheric white matter volume, and high signal on T2 and FLAIR sequences within periventricular and deep white matter. Calcification was apparent on MR in 4 patients. CT scans demonstrated spot and linear calcification in the subependymal region and around areas of porencephaly. Calcification was also visible in the deep cerebral white matter and basal ganglia. 1 patient showed calcification in the central pons.ICC occurs in COL4A1-related disease. The radiological features are distinct from other conditions demonstrating recognisable patterns of ICC, such as congenital cytomegalovirus infection and Aicardi-Goutiéres syndrome. In the absence of a known risk factor for periventricular leukomalacia, the presence of these radio-logical findings should suggest the possibility of COL4A1-related disease.

The Aicardi-Goutières syndrome. Molecular and clinical features of RNAse deficiency and microRNA overload.

Intracellular RNAses are involved in various functions, including microRNA maturation and turnover. Mutations occurring in genes encoding RNAses cause Aicardi-Goutiéres syndrome (AGS). AGS mutations silence RNAse activity, thus inducing accumulation of endogenous RNAs, mainly consisting of short RNAs and microRNAs. Overload of intracellular RNA triggers Toll like receptor-dependent interferon-alpha production in the brain, which in turn activates neurotoxic lymphocytes and inhibits angiogenesis thus inducing the typical clinical phenotype of AGS. However, these pathogenic mechanisms are attenuated after three years of age by the endogenous production of DNAJP58IPK and Cystatin F, which arrest AGS progression. Because RNAses are involved in microRNA turnover, we evaluated the expression of 957 microRNAs in lymphocytes from AGS patients and control patients. Our results indicate that microRNA overload occurs in AGS patients. This upregulation inhibits microRNA turnover impeding the synthesis of the novel microRNAs required for the differentiation and myelination of the brain during the initial period of postnatal life. These pathogenic mechanisms result in AGS, a neurological syndrome characterized by irritability, mild hyperpyrexia, pyramidal and extrapyramidal signs, and spastic-dystonic tetraplegia. Typical cerebrospinal fluid alterations include lymphocytosis and elevated interferon-alpha levels. Brain imaging demonstrates cerebral calcifications, white matter abnormalities, and progressive cerebral atrophy.Thus, evidence exists that mutations silencing intracellular RNases affect microRNA turnover resulting in the severe clinical consequences in the brain characterizing the clinical feature of AGS.

Aicardi-Goutieres syndrome: neuroradiologic findings and follow-up.

BACKGROUND AND PURPOSE: To date, few studies have focused specifically on imaging findings in Aicardi-Goutières syndrome (AGS). We set out to evaluate retrospectively neuroradiologic data from a large sample of patients with AGS, focusing on the pattern of white matter abnormalities and the temporal evolution of the cerebral involvement to establish the radiologic natural history of the disease. MATERIALS AND METHODS: Thirty-six patients, 18 girls and 18 boys, were included. All had a clinical diagnosis of AGS, genetically confirmed in 31 of them. For every subject, we reviewed at least 1 CT and 1 MR imaging study; 19 (52.7%) had multiple examinations. In all, we reviewed 109 examinations. Clinical-neuroradiologic comparisons were analyzed by using the chi(2) test. RESULTS: Calcifications were found in all subjects, mainly in the basal ganglia, lobar white matter, and dentate nuclei. Abnormal white matter was present in all the subjects, showing 2 patterns of distribution: diffuse in 18 (50%) and an anteroposterior gradient in 18 (50%). Cystic areas were observed in the temporal and/or frontal lobes in 12/36 patients (33.3%). A correlation was found between early age at onset and severity of the leukoencephalopathy in the frontal (P = .024) and temporal (P = .034) regions. A significant degree of cerebral atrophy was found in 31/36 subjects (86.1%). The neuroradiologic presentation remained substantially stable with time. CONCLUSIONS: The different neuroradiologic presentations of AGS are here outlined for the first time in a large sample of patients. These findings may facilitate more precise and earlier diagnosis of this rare but probably underdiagnosed syndrome.

Aicardi-Goutieres syndrome.

INTRODUCTION: Aicardi-Goutières syndrome (AGS) is an autosomal recessive encephalopathy characterized by acquired microcephaly, cerebral calcifications, leukodystrophy, cerebral atrophy and cerebrospinal fluid findings of chronic lymphocytosis and raised interferon-alpha (INF-alpha). The main extraneurological symptoms are chilblain-like skin lesions, usually on the fingers, toes and ears. SOURCES OF DATA: This review is based on a search of the published literature on AGS from 1984 onwards (particularly the most recent papers) and on knowledge and experience gained through the authors' work with the International Aicardi-Goutières Syndrome Association (IAGSA). AREAS OF AGREEMENT: It is accepted that AGS can be mistaken for a congenital infection and that the diagnostic significance of its cardinal signs (raised INF-alpha levels, basal ganglia calcifications) is different in different stages of the disease. Currently, we know of four genes that, if mutated, can give rise to AGS, but at least one other gene is believed to exist. These genes are involved in the DNA damage response, a defect of which could provoke an inappropriate innate immune response, triggering increased secretion of INF-alpha, ultimately responsible for the main features of the disease. AREAS OF CONTROVERSY: The natural history of AGS has not yet been definitively described given the lack of extensive, long-term neuroradiological follow-up studies. Furthermore, it is not yet clearly understood how the innate immune system is activated, what triggers the onset of the disease or why it tends to 'burn out' after several months. Immunosuppressive therapy in the active stage of the disease does not seem to produce any real change in the clinical course, but more data are needed. GROWING POINTS AND AREAS TIMELY FOR DEVELOPING RESEARCH: Current studies aim to clarify the molecular mechanisms underlying the pathogenesis of AGS and to establish the exact pathway by which retained nucleic acids activate the immune system. This knowledge could allow the development of therapeutic strategies.

Aicardi-Goutières syndrome presenting atypically as a sub-acute leukoencephalopathy.

Aicardi-Goutières syndrome is an autosomal recessive encephalopathy characterised by acquired microcephaly, basal ganglia calcifications, leukodystrophy, cerebral atrophy, chronic cerebrospinal lymphocytosis, and raised titres of interferon alpha in the cerebrospinal fluid. The disease onset is generally within the first months of life. We here report a case of Aicardi-Goutières syndrome presenting atypically as a sub-acute leukoencephalopathy following satisfactory psychomotor development up to the age of 16 months. This case highlights the importance of considering Aicardi-Goutières syndrome in the differential diagnosis of an unexplained leukoencephalopathy and the possibility of later onset of the disease.

The natural history of Aicardi-Goutières syndrome: follow-up of 11 Italian patients.

Described are the outcomes of 11 Italian patients with Aicardi-Goutières syndrome. Neurologic symptoms progressed in the first year of life and stabilized by the end of the second year in 10 patients. White matter abnormalities remained stable; cerebral atrophy was stable in four patients and progressive in two. Calcifications increased (in number and size) in two of six patients. Serial CSF and serum interferon-alpha measurements (three patients) showed reduced CSF interferon-alpha levels.

Cerebral cavernous angiomas: an atypical case in infancy.

Cerebral cavernous angiomas (CCA) are rare, reportedly accounting for only 1% of all intracranial vascular lesions and 15% of all cerebral vascular malformations. Forms are sporadic or familial, and the mode of inheritance is probably autosomal dominant. We report an unusual case of an infant born at 37 weeks of gestational age following a normal pregnancy. Her birth-weight was 1560 g. The family history was negative. At 10 months of age, the child presented with the sudden onset of muscular hypotonia, motility and strength deficits, and absence of osteotendinous reflexes in the right arm. The psychomotor development of the child was normal. MRI revealed the presence of a cavernous angioma in the paramedian pontine region. The child's monoparesis quickly disappeared. This case is interesting because of the age at onset and the way in which the clinical manifestations developed.

Effect of preterm premature rupture of membranes on neurodevelopmental outcome: follow up at two years of age.

OBJECTIVE: To evaluate the impact of preterm premature rupture of membranes on the neurodevelopmental outcome of infants, assessed at two years of age. DESIGN: A prospective observational study of surviving preterm infants born after premature rupture of membranes and of infants born after spontaneous preterm labour with intact membranes. The study was carried out in the period 1986 to 1991. SETTING: Pavia, Italy. SUBJECTS: One hundred and forty singleton infants born prematurely after premature rupture of membranes between 24 and 34 weeks of gestation and 120 controls of similar gestational age born after spontaneous preterm labour with intact membranes. MAIN OUTCOME MEASURES: Infant neurodevelopmental outcome at two-year follow up. RESULTS: After adjustment, by logistic analysis for the effect of gestational age and birthweight, infants born after premature rupture of membranes were more likely to have severe neurodevelopmental impairment (spastic tetraplegia and/or Bayley mental developmental index < 71) than controls (adjusted OR 5.75, 95% CI 1.22-27.18). Multivariate analysis of linear trend showed a statistically significant relation of duration of membrane rupture to occurrence of severe intraventricular haemorrhage, cystic periventricular leucomalacia and moderate to severe infant neurodevelopmental impairment. CONCLUSION: Infants born after prolonged premature rupture of membranes are at higher risk of subsequent moderate to severe neurodevelopmental impairment than those born after spontaneous labour with intact membranes.

Neurodevelopmental outcome at 5-7 years in preterm infants with periventricular leukomalacia.

We describe outcome at 5-7 years of 37 subjects with periventricular leukomalacia (PVL). Children were divided into 3 groups based on PVL type and clinical outcome. Subjects with cystic PVL > or = 5 mm-1 cm or more (n = 14) all developed CP. CP was found in only 2 subjects out of 11 with cystic PVL < 5 mm. One had GII < 70 according to McCarthy's Scales of Children's abilities. Mild neurological signs were present in 7 and 1 child was normal. Subjects with so-called "prolonged flare" (n = 12) included 6 CP cases, 4 with mild neurological signs and 2 normal subjects. Prognosis was related to site and number of cysts. Cognitive profiles tended to be disharmonic, with discrepancies between verbal, performance and motor scores. We conclude that PVL represents an important diagnostic tool in both short and long-term neurodevelopmental outcome.

Neurodevelopmental outcome in very-low-birth-weight infants with or without periventricular haemorrhage and/or leucomalacia.

The aim of the study was to verify the predictive value of ultrasound performed in the neonatal period for short-term neurodevelopmental prognosis in 122 preterm very-low-birth-weight infants followed-up at 36 months. Neuromotor development was favourable in 53 (87%) subjects with normal ultrasound findings and in 21 (81%) subjects presenting uncomplicated haemorrhage. However, sensory and/or cognitive sequelae developed in 13% and 19% of the two groups, respectively. Outcome was unfavourable in 14 (50%) of 28 patients with ultrasound findings of complicated cerebral haemorrhages and in 5 (71%) of those (7) with ultrasound findings of parenchymal lesions without haemorrhage. Neonatal ultrasound examination seems to be fundamental in predicting neuromotor, but not cognitive, outcome in very-low-birth-weight infants.