Edvige Veneselli

De novo mutations in ATP1A3 cause alternating hemiplegia of childhood

Alternating hemiplegia of childhood (AHC) is a rare, severe neurodevelopmental syndrome characterized by recurrent hemiplegic episodes and distinct neurological manifestations. AHC is usually a sporadic disorder and has unknown etiology. We used exome sequencing of seven patients with AHC and their unaffected parents to identify de novo nonsynonymous mutations in ATP1A3 in all seven individuals. In a subsequent sequence analysis of ATP1A3 in 98 other patients with AHC, we found that ATP1A3 mutations were likely to be responsible for at least 74% of the cases; we also identified one inherited mutation in a case of familial AHC. Notably, most AHC cases are caused by one of seven recurrent ATP1A3 mutations, one of which was observed in 36 patients. Unlike ATP1A3 mutations that cause rapid-onset dystonia-parkinsonism, AHC-causing mutations in this gene caused consistent reductions in ATPase activity without affecting the level of protein expression. This work identifies de novo ATP1A3 mutations as the primary cause of AHC and offers insight into disease pathophysiology by expanding the spectrum of phenotypes associated with mutations in ATP1A3.

Neuroblastoma with symptomatic spinal cord compression at diagnosis: Treatment and results with 76 cases

PURPOSE To report on the treatment of patients with newly diagnosed neuroblastoma presenting with spinal cord compression (SCC). PATIENTS AND METHODS Of 1,462 children with neuroblastoma registered between 1979 and 1998, 76 (5.2%) presented with signs/symptoms of SCC, including motor deficit in 75 patients (mild in 43, moderate in 22, severe [ie, paraplegia] in 10), pain in 47, sphincteric deficit in 30, and sensory loss in 11. Treatment of SCC consisted of radiotherapy in 11 patients, laminectomy in 32, and chemotherapy in 33. Laminectomy was more frequently performed in cases with favorable disease stages and in those with severe motor deficit, whereas chemotherapy was preferred in patients with advanced disease. RESULTS Thirty-three patients achieved full neurologic recovery, 14 improved, 22 remained stable, and eight worsened, including three who become paraplegic. None of the 10 patients with grade 3 motor deficit, eight of whom were treated by laminectomy, recovered or improved. In the other 66 patients, the neurologic response to treatment was comparable for the three therapeutic modalities. All 11 patients treated by radiotherapy and 26 of 32 patients treated by laminectomy, but only two of 33 treated by chemotherapy, received additional therapy for SCC. Fifty-four of 76 patients are alive at time of the analysis, with follow-up of 4 to 209 months (median, 139 months). Twenty-six (44%) of 54 survivors have late sequelae, mainly scoliosis and sphincteric deficit. CONCLUSION Radiotherapy, laminectomy, and chemotherapy showed comparable ability to relieve or improve SCC. However, patients treated with chemotherapy usually did not require additional therapy, whereas patients treated either with radiotherapy or laminectomy commonly did. No patient presenting with (or developing) severe motor deficit recovered or improved. Sequelae were documented in 44% of surviving patients.

Hypersomnia in the Prader Willi syndrome: clinical-electrophysiological features and underlying factors

OBJECTIVE Excessive daytime sleepiness is a common symptom in Prader Willi syndrome (PWs). Sleep disordered breathing (SDB) and narcoleptic traits such as REM sleep onsets (SOREMPs) have been reported in these subjects. We evaluated nighttime and daytime sleep patterns in patients with PWs in order to clarify the nature of their hypersomnia. DESIGN AND METHODS We performed overnight continuous EEG-polysomnographic studies (with breathing monitoring included) in 14 subjects (6 M,8 F; mean age 17 years, range 8-37) affected by PWs unselected for sleep disturbances. Ten patients underwent a Multiple Sleep Latency Test (MSLT) the day following the nocturnal sleep studies. Patients assessment was completed by means of immunogenetic characterization. RESULTS Nocturnal polysomnographic investigation documented sleep related breathing abnormalities such as central apneas, hypopneas or hypoventilation which mainly occurred during REM sleep in 8 subjects and did not cause sleep disruption. Only 4 subjects presented an increase in the Respiratory Disorder Index (RDI) slightly above the normal limits. In 8 subjects out of 10, with and without SDB, the mean daytime sleep latency could be considered abnormal according to the Tanner staging of pubertal development. Five patients showed at least two SOREMPs at MSLT. Subjects with and without SOREMPs had, respectively, a mean age of 18.6 SD 7.9 (4 M, 1 F) and 14.5 SD 2.9 (4 F, 1 M). The paternal deletion:uniparental dysomy ratio at genotypic characterization was 4:1 and 3.5:1 in subjects with and without SOREMPs, respectively. No patient presented DR-15 nor Dq-6. CONCLUSIONS Excessive sleepiness is a frequent disturbance in PWs. Subgroups of PW patients show hypersomnolence and SOREMPs. Sleep disordered breathing appears to have a limited role in the genesis of hypersomnia which not seems on the other hand attributable to the coexistence of narcolepsy phenotype. Hypersomnia in PW syndrome is likely to mainly be attributable to a primary hypothalamic dysfunction. The potential interacting role of other factors such as subjects age, sex and genetic pattern is suggested and deserve further investigation.

Epilepsy in Rett syndrome: clinical and genetic features.

Epilepsy often occurs in Rett syndrome and is considered a major problem. The aim of this study was to define the clinical features of epilepsy and the correlation between seizures and both genotype and clinical phenotype in the Rett population. One hundred sixty-five patients with Rett syndrome referred to four Italian centers were recruited. All patients underwent video/EEG monitoring and molecular analysis of the MECP2 gene or, in negative cases, of the CDKL5 and FOXG1 genes. The frequency of epilepsy was 79%. Drug-resistant epilepsy occurred in 30% of all our patients with Rett syndrome and in 38% of those with epilepsy. Our findings demonstrate that epilepsy differs among the various phenotypes and genotypes with respect to age at onset, drug responsiveness, and seizure semiology. The Hanefeld and preserved speech variants represent the extremes of the range of severity of epilepsy: the preserved speech variant is characterized by the mildest epileptic phenotype as epilepsy is much less frequent, starts later, and is less drug resistant than what is observed in the other phenotypes. Another important finding is that seizure onset before 1 year of age and daily frequency are risk factors for drug resistance. Thus, this study should help clinicians provide better clinical counseling to the families of patients with Rett syndrome.

Long-Term Follow-Up of Neuroblastoma-Associated Opsoclonus-Myoclonus-Ataxia Syndrome

OBJECTIVE The aim of this study is to describe the long-term neurological, neuropsychological and neuroradiological sequelae and to determine prognostic factors for neurological outcome in children with neuroblastoma-associated opsoclonus-myoclonus-ataxia (OMA) syndrome. METHODS Data on medical history were collected for the study patients. Examinations with grading of neurological signs, neuropsychological tests and brain magnetic resonance imaging with spectroscopy were performed during a follow-up clinic. RESULTS Fourteen subjects entered the study. All had localized neuroblastoma and they were evaluated after a median of 7.8 years. Patients with a chronic/multiphasic neurological course received steroids combined with intravenous immunoglobulins in the majority of cases. 71% presented neurological sequelae and 62% had a full-scale IQ below the normal range. All patients showed at least some deficit in the neuropsychological functions assessed (language, visual-motor integration, memory, attention and motor ability). Long-term deficits were more frequently detected in patients with an interval of more than 2 months between OMA onset and its diagnosis, even if in most comparisons statistical significance was not reached. Cerebellar atrophy, observed in 36% of patients, was not associated with the neurological outcome. CONCLUSIONS Persisting disability is present in most children with neuroblastoma-associated OMA. However, our results support the role of an early diagnosis of OMA in reducing sequelae and encourage the use of new immunosuppressive therapies.

Metabolic and genetic risk factors for migraine in children

Migraine can induce ischaemic stroke, and is considered an independent risk factor for stroke in the young. To date, the nature of the link between migraine and stroke is essentially unknown. Forty-five children were studied. Homocysteine levels (fasting and post methionine load), vitamin B12 and plasma folate levels, factor V Leiden, factor II G20210A, methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C mutations were examined. Compared with controls, patients with migraine had higher levels of post-methionine load homocysteine values (19.5 ± 4.9 vs. 16.9 ± 1.9; P = 0.025) and significantly lower folate levels (5.8 ± 2.6 vs. 7.5 ± 2.1; P = 0.002). We found a trend toward an increased risk of migraine in subjects carrying a homozygous mutant genotype for MTHFR C677T and MTHFR A1298C polymorphisms. Genetic prothrombotic conditions do not seem to be related to migraine in the young, whereas the biochemical differences between migrainous patients and controls are an appealing topic for further investigation.

Effect of steroid and high-dose immunoglobulin therapy on opsoclonus-myoclonus syndrome occurring in neuroblastoma.

The authors describe a case of an 8-month-old boy with opsoclonus-myoclonus syndrome (OMS) and coincident unresectable neuroblastoma (NB). He achieved a complete remission for NB after 6 courses of standard-dose chemotherapy without significant neurological improvement despite the use of steroids and high-dose immunoglobulin (HIG), administered separately. Only the combined treatment withthese two drugs induced a complete disappearance of neurological symptoms. On the basis of this experience, the authors suggest the association of steroids plus HIG for the treatment of OMS in patients not responsive to conventional first line therapy with steroids.

The relationship between group A streptococcal infections and Tourette syndrome: a study on a large service-based cohort

Aim  To evaluate the relationship between diagnosis and clinical course of Tourette syndrome and group A Streptococcus (GAS).

Malignant migrating partial seizures in infancy

A previously unreported epileptic condition characterised by onset before 6 months of age, nearly continuous electroencephalographic seizures involving multiple independent areas originating in both hemispheres, no identifiable cause, and poor outcome has been described by Coppola et al. We report three cases presenting the same clinical and EEG pictures. They show a peculiar epileptic condition unlike the other early epileptogenic encephalopathies, so they may represent a new infantile epileptic syndrome.

Phenylketonuria: diet for life or not?

Cerone R, Schiaffino MC, Di Stefano S, Veneselli E. Phenylketonuria: diet for life or not? Acta Pædiatr 1999; 88: 664‐6. Stockholm. ISSN 0803‐5253