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Michele Zappella

Publications and source records attributed to Michele Zappella.

15 recordsLinked to original sources
PubMed2007

Italian Rett database and biobank.

Rett syndrome is the second most common cause of severe mental retardation in females, with an incidence of approximately 1 out of 10,000 live female births. In addition to the classic form, a number of Rett variants have been described. MECP2 gene mutations are responsible for about 90% of classic cases and for a lower percentage of variant cases. Recently, CDKL5 mutations have been identified in the early onset seizures variant and other atypical Rett patients. While the high percentage of MECP2 mutations in classic patients supports the hypothesis of a single disease gene, the low frequency of mutated variant cases suggests genetic heterogeneity. Since 1998, we have performed clinical evaluation and molecular analysis of a large number of Italian Rett patients. The Italian Rett Syndrome (RTT) database has been developed to share data and samples of our RTT collection with the scientific community (http://www.biobank.unisi.it). This is the first RTT database that has been connected with a biobank. It allows the user to immediately visualize the list of available RTT samples and, using the "Search by" tool, to rapidly select those with specific clinical and molecular features. By contacting bank curators, users can request the samples of interest for their studies. This database encourages collaboration projects with clinicians and researchers from around the world and provides important resources that will help to better define the pathogenic mechanisms underlying Rett syndrome.

Databases as Topic↗
PubMed2006

Kabuki syndrome with trichrome vitiligo, ectodermal defect and hypogammaglobulinemia A and G.

We report a unique combination of symptoms in a case of Kabuki syndrome (KS), a multiple malformation/mental retardation syndrome that has a prevalence of 1:32,000 to 1:86,000. The patient was a mentally delayed 12-year-old male with trichrome vitiligo, ectodermal defect, and hypogammaglobulinemia A and G. This unique combination of signs, described here for the first time, indicates that KS comprises multiple deficits that affect not only the brain, but ectoderm-derived structures and the immune system as well. Our report may provide important clues for understanding the pathogenesis of the KS.

Abnormalities, Multiple↗
PubMed2006

Reversible PDD.

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Adolescent↗
PubMed2005

Global developmental delay, osteopenia and ectodermal defect: a new syndrome.

UNLABELLED: Global developmental delay is a serious social problem. It is often unrecognized and the phenotypes are inadequately studied. To investigate the phenotypes of children with aspecific central nervous system (CNS) impairment (poor speech, maladaptive behavioral symptoms such as temper tantrums, aggressiveness, poor concentration and attention, impulsiveness, and mental retardation). SETTING: Tertiary care hospital. PATIENTS: Three children (two male siblings, and one unrelated girl). METHODS: We used the results from clinical neurological evaluations; imaging and electrodiagnostic studies; metabolic and genetic tests; skin biopsies and bone mineral densitometry. All three children suffered from (A) global developmental delay, (B) osteopenia, and (C) identical skin defects. The skin ultrastructural abnormalities were abnormal keratin differentiation, consisting of hyperkeratosis and granular layer thickening; sweat gland abnormalities, consisting of focal, cytoplasmic clear changes in eccrine secretory cells; and melanocyte abnormalities, with both morphological changes (reduced number and size without evident dendritic processes), and functional changes (defects in the migration of melanosomes in the keratinocytes). These patients present a previously unrecognized syndrome. We retain useful to report this new association, to be recognized, in the next future, as a specific key-sign of a well-defined genetic defect.

Biopsy↗
PubMed2005

Myoclonic encephalopathy in the CDKL5 gene mutation.

OBJECTIVE: Epilepsy with mutation of the CDKL5 gene causes early seizures and is a variant of Rett syndrome (MIM (312750), which is reported typically as infantile spasms. The purpose of this study was to analyze the epileptic histories and EEGs of patients with the CDKL5 mutation. METHODS: We reviewed the epilepsy histories and electroclinical analyses of three girls aged 9.5, 7.4, and 9.4 years, each with a mutation of the CDKL5 gene. RESULTS: We revealed the presence of an encephalopathy that started by 1.5 months of age. At first, seizures involved tonic spasms or complex partial seizures, and were complicated by the later appearance of complex partial, tonic, and unexpectedly, myoclonic seizures. This form of epilepsy was drug resistant. Routine and prolonged video EEGs both displayed a homogeneous electroclinical pattern consisting of (a) unique background with diffuse high voltage sharp waves of 6-7 Hz, and absence of the typical rhythmic frontal-central theta activity present in Rett syndrome; (b) unique awake and sleep background, with diffuse, high voltage, continuous sharp waves with multifocal and diffuse spikes; (c) rhythmic, diffuse, 15 Hz activity accompanied clinically by tonic seizures; (d) intercritical pattern with pseudoperiodic, diffuse, sharp waves or pseudoperiodic, diffuse spike and polyspike or wave discharges; and (e) diffuse, spike, polyspike and wave discharges accompanied by massive or focal myoclonias or both. CONCLUSIONS: Patients with the CDKL5 mutation have an early onset, epileptic encephalopathy in infancy that evolves into myoclonic seizures in childhood with a unique EEG pattern. SIGNIFICANCE: Recognizing this type of encephalopathy could be useful in prompting clinicians to proceed further with their diagnostic work in patients not fitting the criteria of classical Rett syndrome.

Child↗
PubMed2005

CDKL5 belongs to the same molecular pathway of MeCP2 and it is responsible for the early-onset seizure variant of Rett syndrome.

Rett syndrome (RTT) is a severe neurodevelopmental disorder almost exclusively affecting females and characterized by a wide spectrum of clinical manifestations. Most patients affected by classic RTT and a smaller percentage of patients with the milder form 'preserved speech variant' have either point mutations or deletions/duplications in the MECP2 gene. Recently, mutations in the CDKL5 gene, coding for a putative kinase, have been found in female patients with a phenotype overlapping with that of RTT. Here, we report two patients with the early seizure variant of RTT, bearing two novel CDKL5 truncating mutations, strengthening the correlation between CDKL5 and RTT. Considering the similar phenotypes caused by mutations in MECP2 and CDKL5, it has been suggested that the two genes play a role in common pathogenic processes. We show here that CDKL5 is a nuclear protein whose expression in the nervous system overlaps with that of MeCP2, during neural maturation and synaptogenesis. Importantly, we demonstrate that MeCP2 and CDKL5 interact both in vivo and in vitro and that CDKL5 is indeed a kinase, which is able to phosphorylate itself and to mediate MeCP2 phosphorylation, suggesting that they belong to the same molecular pathway. Furthermore, this paper contributes to the clarification of the phenotype associated with CDKL5 mutations and indicates that CDKL5 should be analyzed in each patient showing a clinical course similar to RTT but characterized by a lack of an early normal period due to the presence of seizures.

Age of Onset↗
PubMed2005

Attention-deficit/hyperactivity disorder (ADHD) and variable clinical expression of Aarskog-Scott syndrome due to a novel FGD1 gene mutation (R408Q).

Mutations of the FGD1 gene are responsible for a significant proportion of patients with Aarskog-Scott syndrome (AAS), an X-linked disorder characterized by short stature, brachydactyly, urogenital abnormalities, and a typical dysmorphic facial appearance. Although mental retardation does not occur significantly in AAS, this condition has been described associated with various degrees of mental impairment and/or behavioral disorders in some patients. In particular, attention deficit hyperactivity disorder (ADHD) is reported as a common characteristic of AAS. However, AAS/ADHD reported patients have been only clinically described, and diagnosis never has been confirmed on molecular basis. We present here a unique case of a 16-years-old patient presenting with ADHD, lower intelligence quotient, and dysmorphic features. Although the clinical features were not completely typical of AAS, genetic analysis demonstrated a novel FGD1 missense mutation (R408Q). The case we report confirms the highly variable expressivity of AAS and first documents that the FGD1 gene may play a role in ADHD susceptibility. We suggest that FGD1 analysis may be adequate in ADHD patients who exhibit dysmorphic features suggestive of AAS, also in the absence of the full phenotypical spectrum.

Abnormalities, Multiple↗
PubMed2005

Epilepsy, electroencephalographic abnormalities, and regression in children with autism.

The association of epilepsy and autism is recognized, and it has been reported at a percentage that varies between 8 and 42%, depending on age and diagnostic criteria. One third of autistic children undergo a regression of language and behavior between 2 and 3 years, and epileptiform abnormalities and epilepsy can be concomitant in an undetermined percentage of them. The aim of this study was to investigate the prevalence of epilepsy and paroxysmal abnormalities in a group of children with autism and to determine the percentage of regression course in this group. Forty-six patients with autism (mean age 7.8 +/- 2.7 years; 34 boys and 12 girls) were consecutively examined, and clinical evaluation, assessment, and electroencephalographic (EEG) recordings were performed in all of them. Thirty-five percent showed paroxysmal abnormalities and epilepsy, 22% had only paroxysmal abnormalities without seizures, and 13% of the children suffered from epilepsy. Sixty-five percent had a normal EEG. No difference in regression rate was observed between patients with paroxysmal abnormalities and epilepsy and those with a normal EEG and without seizures. In the study group, the prevalence of epilepsy was in the low range of individuals with autism, and different types of epilepsy were observed. Autism with regression was not influenced by paroxysmal abnormalities and epilepsy.

Autistic Disorder↗
PubMed2004

Real-time quantitative PCR as a routine method for screening large rearrangements in Rett syndrome: Report of one case of MECP2 deletion and one case of MECP2 duplication.

Mutations in the X-linked methyl-CpG-binding protein 2 gene (MECP2) are found in 70-80% of cases of classical Rett syndrome (RTT) and in about 50% of cases of preserved speech variant (PSV). This high percentage of MECP2 mutations, especially in classical RTT cases, suggests that another major RTT locus is unlikely. Missed mutations may be due to the limited sensitivity of the methodology used for mutation scanning and/or the presence of intronic mutations. In a double-copy gene, such as MECP2 in females, current methodologies (e.g., DGGE, SSCP, DHPLC, direct sequencing) are prone to miss gross rearrangements. Three previous reports during 2001-2003 have shown the presence of large deletions in a fraction of MECP2-negative classical RTT patients. We developed a reliable, single tube, quantitative PCR assay for rapid determination of MECP2 gene dosage. This method involves a multiplex reaction using a FAM labeled TaqMan probe with a TAMRA quencher derived from MECP2 exon 4 and two primers derived from the same exon and RNAaseP as an internal reference. The copy number of the MECP2 gene was determined by the comparative threshold cycle method (ddCt). Each sample was run in quadruplicate. We validated this assay through the analysis of 30 healthy controls (15 female and 15 male) and we then applied this method to eight classical RTT and six PSV patients, all negative for MECP2 mutations. We identified gross rearrangements in two patients: a deletion in a classical RTT patient and a duplication in a PSV patient. Our results confirm that a fraction of MECP2-negative RTT cases have MECP2 gross rearrangements and we propose real-time quantitative PCR as a simple and reliable method for routine screening of MECP2 in addition to DHPLC analysis.

Adult↗
PubMed2004

Lymphoblastoid cell lines of Rett syndrome patients exposed to oxidative-stress-induced apoptosis.

Despite the identification of mutations in the methyl CpG binding protein 2 gene, the pathogenesis of Rett syndrome (RS) is still unknown. In order to clarify the role of apoptosis in this disorder, we studied lymphoblastoid cell lines in five classical RS patients and five controls, incubated with 2-deoxy-d-ribose (dRib), a reducing sugar that induces apoptosis in human cells, through oxidative damage. The apoptotic response was detected by flow cytometric analysis and agarose gel electrophoresis. The cells of RS patients showed a lower percentage of apoptosis in a routine condition than those of controls did, whereas, in the presence of dRib, the percentage of apoptotic cells in RS patients increased with time and reached the same percentage of those of controls at 72 h. The data observed here suggest that RS may have a low susceptibility or an increased resistance to the apoptotic cell death, which may be corrected only in the presence of a strong apoptotic stimulus.

Adolescent↗
PubMed2004

Three Rett patients with both MECP2 mutation and 15q11-13 rearrangements.

Autism and Rett syndrome, a severe neurological disorder with autistic behavior, are classified as separate disorders on clinical and etiological ground. Rett syndrome is a monogenic X-linked dominant condition due to de novo mutations in the MECP2 gene, whereas autism is a neurodevelopmental and behavioral disorder with complex genetic basis. Maternally inherited duplications on 15q11-q13 are found in a fraction of autistic children suggesting that an abnormal dosage of gene(s) within this region might cause susceptibility to autism. Now we show that three Rett patients are carriers of both a MECP2 mutation and a 15q11-q13 rearrangement, suggesting that there might be a relationship between autism-related genes and the MECP2 gene.

Chromosomal Proteins, Non-Histone↗
PubMed2003

Study of MECP2 gene in Rett syndrome variants and autistic girls.

Mutations in MECP2 gene account for approximately 80% of cases of Rett syndrome (RTT), an X-linked severe developmental disorder affecting young girls, as well as for most cases of Preserved Speech Variant (PSV), a mild RTT variant in which autistic behavior is common. The aim of this study is to determine whether MECP2 mutations are responsible for PSV only or may cause other forms of autistic disorders. We screened for mutations by SSCP 19 girls with a clinical diagnosis of autism, two of them fulfilling the PSV criteria. A pathogenic mutation was found only in the latter two cases (R133C and R453X). A long follow-up of these two girls revealed a unique clinical course. They initially developed the first three stages of RTT, they were severely retarded and had autistic behavior. Over the years their abilities increased progressively and by early adolescence they lost autistic behavior, becoming adequately accustomed to people and reaching an IQ close to 45. These results confirm previous clinical studies suggesting that a wide spectrum of RTT exists including girls with mental abilities considerably higher than in classic RTT. We conclude that MECP2 mutations (missense or late truncating) can be found in girls with an IQ close to 45 and a clinical history of PSV of Rett syndrome. Furthermore, MECP2 mutations are not found in patients in which autism remains stable over the years.

Adolescent↗
PubMed2002

Analysis of ten candidate genes in autism by association and linkage.

We studied the possible involvement of ten candidate genes in autism: proenkephalin, prodynorphin, and proprotein convertase subtilisin/kexin type 2 (opioid metabolism); tyrosine hydroxylase, dopamine receptors D2 and D5, monoamine oxidases A and B (monoaminergic system); brain-derived neurotrophic factor, and neural cell adhesion molecule (involved in neurodevelopment). Thirty-eight families with two affected siblings and one family with two affected half-siblings, recruited by the Paris Autism Research International Sibpair Study (PARIS), were tested using the transmission disequilibrium test and two-point affected sib-pair linkage analysis. We found no evidence for association or linkage with intragenic or linked markers. Our family sample has good power for detecting a linkage disequilibrium of 0.80. Thus, these genes are unlikely to play a major role in the families studied, but further studies in a much larger sample would be needed to highlight weaker genetic effects.

Alleles↗
PubMedDate not supplied

Autistic epileptiform regression.

Autistic regression is a well known condition that occurs in one third of children with pervasive developmental disorders, who, after normal development in the first year of life, undergo a global regression during the second year that encompasses language, social skills and play. In a portion of these subjects, epileptiform abnormalities are present with or without seizures, resembling, in some respects, other epileptiform regressions of language and behaviour such as Landau-Kleffner syndrome. In these cases, for a more accurate definition of the clinical entity, the term autistic epileptifom regression has been suggested. As in other epileptic syndromes with regression, the relationships between EEG abnormalities, language and behaviour, in autism, are still unclear. We describe two cases of autistic epileptiform regression selected from a larger group of children with autistic spectrum disorders, with the aim of discussing the clinical features of the condition, the therapeutic approach and the outcome.

Anticonvulsants↗