Multigeneration maternal transmission in Italian families with neural tube defects.

Periconceptional vitamin supplementation with folate prevents about three-quarters of expected cases of neural tube defects (NTDs) in clinical trials. However, vitamin action may be regulated at the level of the gene, and individual susceptibility to environmental agents, including dietary components, also may be under genetic control. We investigated the presence of familial factors in a retrospective case control study of neural tube defects in Genoa, Italy. Cases included all patients treated at a single pediatric neurosurgical service. Controls matched on age and sex came from the same hospital. We found strong evidence for the contribution of genetic factors in this study. There was an excess risk of 14 for the occurrence of NTDs in first-degree relatives compared to controls (P < .0005). There was no difference in sex ratio in any group of relatives, but maternal grandparents of children with a high spinal lesion had 14% fewer off-spring than paternal grandparents (P < .005), possibly because of excess miscarriages. Our study is the first to show complex patterns of inheritance in spina bifida families affecting three generation in one clinical subgroup and preferentially on the mother's side. These results support a role for genomic imprinting and highlight the value of multidisciplinary epidemiologic and clinical studies that include multiple generations. New studies incorporating dietary and genetic approaches will help clarify and extend these findings.

Folate pathway gene alterations in patients with neural tube defects.

Periconceptional folate supplementation reduces the recurrence and occurrence risk of neural tube defects (NTD) by as much as 70%, yet the protective mechanism remains unknown. Inborn errors of folate and homocysteine metabolism may be involved in the aetiology of NTDs. Previous studies have demonstrated that both homozygosity for the C677T mutation in the methylenetetrahydrofolate reductase (MTHFR) gene, and combined heterozygosity for the C677T and for another mutation in the same gene, the A1298C polymorphism, represent genetic risk factors for NTDs. In an attempt to identify additional folate related genes that contribute to NTD pathogenesis, we performed molecular genetic analysis of folate receptors (FRs). We identified 4 unrelated patients out of 50 with de novo insertions of pseudogene (PS)-specific mutations in exon 7 and 3'UTR of the FRalpha gene, arising by microconversion events. All of the substitutions affect the carboxy-terminal amino acid membrane tail, or the GPI anchor region of the nascent protein. Furthermore, among 150 control individuals, we also identified one infant with a gene conversion event within the FRalpha coding region. This study, though preliminary, provides the first genetic association between molecular variations of the FRalpha gene and NTDs and suggests that this gene can act as a risk factor for human NTD.

Expression of histone H3 cell cycle-related gene, vimentin and MYC genes in pediatric brain tumors. A preliminary analysis showing the different malignant cell growth potential.

Eleven pediatric brain tumors were studied for the histone H3, Vimentin and MYC gene expression. H3, an S phase cell cycle-related gene (ccr), was found prevalently expressed in tumors with a high mitotic index (MI). Vimentin gene, which contributes to maintaining the cell structure but is also demonstrated to be an early responder gene to growth stimulation was found variously expressed. The different expression of Vimentin gene in the examined samples suggests the active proliferation of the tumor cells. Analysis of MYC gene expression was found increased only in a mesenchymal chondrosarcoma while in other samples MYC mRNA was undetectable. Medulloblastoma, chondrosarcoma, and choroid plexus carcinoma have high S phase H3 gene expression associated with a high MI. Differently an astrocytoma shows a low MI associated with high H3 gene expression. This first preliminary report of H3, Vimentin and MYC gene expression in brain tumors demonstrates that malignant cells are characterized by a different gene expression and different growth potentials.

Nerve supply and experimental myotonia in rats.

20, 25-Diazacholesterol does not induce myotonia in denervated mammalian skeletal muscle, and cordotomy also renders the muscles resistant to the induction of myotonia. Denervation of muscle already rendered myotonic, has no effect on the intensity of the phenomenon. Finally, tenotomy and posterior rhizotomy leave the myotonic activity in the "deafferentated" muscles unchanged. These findings are discussed in relation to "trophic" influences of the motor pathways on the postsynaptic structures of skeletal muscle.

Cyst of the choroid plexus of the left lateral ventricle.

A cyst of the choroid plexus of the left ventricle is described. The cyst was lined by a choroidal epithelium and filled with cerebrospinal fluid. It produced an intermittent obstructive syndrome. The cyst was almost completely invaginated into the third ventricle, simulating an expanding process in the third ventricle. After microsurgical removal, the recovery of the patient was complete. Electronmicroscopy of the cyst wall is reported. Histological and neuroradiological features are discussed.

Microsurgical excision of a strio-insular arteriovenous malformation.

The complete microsurgical removal of a right strio-insular arteriovenous malformation is described. The surgery was performed in two successive operations. The rationale for these operations is discussed.

Report on a patient with congenital muscular dystrophy, hydrocephalus, Dandy-Walker malformation and leukodystrophy.

We report on a patient affected by congenital muscular dystrophy, severe psychomotor retardation, severe hypotonia, papillar hypoplasia and peculiar NMR pattern of hydrocephalus, Dandy-Walker malformation and leukodystrophy. These findings are intermediate between Walker-Walburg syndrome, Fukuyama disease and Occidental congenital muscular dystrophy. Our case focuses on the wide spectrum of congenital muscle dystrophy associated with central nervous system disease and on the difficulties of genetic counseling in these families.

Cytogenetics of the tissue involved in neural tube defects.

Cytogenetic techniques were used to study the tissue involved in neural tube defects. Eighteen patients have been evaluated and no specific alterations have been detected. We conclude that, whatever are the mechanisms that lead to neural tube defect, their origins must be searched for at the molecular level.

Chiari complex in children--neuroradiological diagnosis, neurosurgical treatment and proposal of a new classification (312 cases).

Chiari malformations are a group of anomalies particularly involving the hindbrain and cervical spinal cord. Since these malformations present many common features, we called them "Chiari Complex". After reviewing our 312 patients affected by different types of Chiari malformations we propose the following classification: Chiari I (30 cases): 1) This malformation may be divided in two sub-types: a) classic and b) myelencephalic forms. 2) Only three children were admitted with specific clinical symptoms and they had an occipito-cervical surgical decompression. Chiari II (276 cases): 1) Most of our patients (70%) presented with progressive hydrocephalus and they needed a CSF shunt to be inserted. 2) Seven sub-types of 4th ventricle morphology and size were identified. 3) Only 11 patients underwent a cervical decompression; in 182 children CSF shunting resulted in a good clinical outcome. Chiari III (2 cases): Chiari II signs must be associated with an occipito-cervical cephalocele. In both cases there were other severe associated CNS malformations. Chiari IV (4 cases): We propose this name for patients with myelomeningocele (MMC) and severe cerebellar hypoplasia.

Polymorphisms in genes involved in folate metabolism as risk factors for NTDs.

Moderate hyperhomocysteinemia in pregnant women has been associated with an increased risk of neural tube defects (NTDs). Periconceptional supplementation with multi-vitamins containing folic acid may normalize homocysteine metabolism and decrease the NTD risk. The C677 T variant of the MTHFR gene coding for a thermolabile enzyme has been described as the first genetic risk factor that accounts for a group of NTDs characterized by low maternal folate status and high homocysteine concentrations. Another common mutation of the same MTHFR gene, A1298 C, has also been described as an NTD risk factor. In addition to abnormal folate metabolism, anything that compromises the internalization of folate into the cell may be involved in the pathogenesis of NTDs. For this reason, a common polymorphism in the RFC-1 gene encoding the reduced folate carrier protein (A80 G) could also be an additional NTD risk factor. In the present study we examined the genotypic distributions and the allele frequencies of MTHFR A1298 C and RFC-1 A80 G polymorphisms in DNA samples from healthy Italian individuals and compared them to the frequencies observed in NTD cases and their parents. By means of restriction enzymatic analysis, we determined that the frequency of the mutated C allele of the A1298 C mutation was 0.25 among control individuals, which is in the range of that recently reported in other ethnic groups. However, we report that the mutant C allele frequencies are significantly higher among NTD cases and case mothers than among controls (0.39, 0.44, 0.25). Furthermore, for the RFC-1 A80 G mutation, we found that the frequency of the G allele of the RFC-1 mutation was 0.46 in the control population, suggesting that this is a common polymorphism in the Italian population. In spite of the high prevalence of the 80 G/G genotype among healthy subjects, we observed an increased frequency of the G allele in NTD-affected children, and their mothers and fathers. These preliminary results indicate that both the MTHFR and RFC-1 polymorphisms may play a role in NTD risk, at least in the Italian population. Further studies should be directed toward the evaluation of the level of risk conferred by the mutant MTHFR and RFC-1 genotypes, as well as the interaction between these genetic determinants and other nutritional and environmental factors.

[Meningoencephalitis in children and computerized axial tomography. Clinico-prognostic evaluation]. / Meningoencefaliti in età pediatrica e T.A.C. Valutazioni clinico-prognostiche.

A large casistic of severe CNS infectious diseases in pediatric age was reviewed to underline mean clinic, EEG features and correlated them with CT images. We conclude that CT scanning is useful in CNS infectious diseases, above all in the first life years, because it can provide diagnostic and prognostic information and sometimes therapeutic indication.

[Crouzon's syndrome. Description of a case treated surgically in the fifth month of life]. / La sindrome di Crouzon. Descrizione di un caso trattato chirurgicamente entro il quinto mese di vita.

The authors describe a case of Crouzon syndrome, characterized by unusually early and serious symptoms, and surgically corrected during the fifth month of life, with good clinical and aesthetic results.