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Biomedical subjects

Paolo Balestri

Publications and source records attributed to Paolo Balestri.

At least 19 recordsLinked to original sources

Mutations in the C7orf11 (TTDN1) gene in six nonphotosensitive trichothiodystrophy patients: no obvious genotype-phenotype relationships.

Trichothiodystrophy (TTD) is a rare autosomal recessive disorder whose defining feature is brittle hair. Associated clinical symptoms include physical and mental retardation of different severity, ichthyosis, premature aging, and, in half of the patients, photosensitivity. Recently, C7orf11 (TTDN1) was identified as the first disease gene for the nonphotosensitive form of TTD, being mutated in two unrelated cases and in an Amish kindred. We have evaluated the involvement of TTDN1 in 44 unrelated nonphotosensitive TTD cases of different geographic origin and with different disease severity. Mutations were found in six patients, five of whom are homozygous and one of whom is a compound heterozygote. All five identified mutations are deletions that have not been described before. Three are deletions of a few bases, resulting in frameshifts and premature termination codons. The other two include the whole TTDN1 gene, suggesting that TTDN1 is not essential for cell proliferation and viability. The severity of the clinical features does not correlate with the type of mutation, indicating that other factors besides TTDN1 mutations influence the severity of the disorder. Since only a small proportion of the analyzed cases were mutated in TTDN1, the nonphotosensitive form of TTD is genetically heterogeneous. Mutations in TTDN1 do not affect the response to ultraviolet (UV) light or the steady state level of the repair/transcription factor IIH (TFIIH), which is central to the onset of the photosensitive form of TTD.

Adolescent↗

Photoparoxysmal responses in children with chromosomal aberrations.

Electroencephalographic (EEG) anomalies and epilepsy are commonly observed in the clinical picture of patients with chromosomal aberrations. However, no investigations have been performed on the relationship between chromosomal disorders and photoparoxysmal response (PPR). In this study, we evaluate the characteristics of PPRs elicited with intermittent photic stimulation during a routine electroencephalogram in children affected by chromosomal anomalies and correlated this with the clinical profile of the child. A review of the literature has also been performed. PPRs occurred in 14% (4/28) of patients. PPRs were brief (<less 5s), self-limited, elicited by several series of flashes, with an onset latency between 2 and 9s, and scarcely controlled by anticonvulsants. Although further studies are needed to confirm the present data, our observations and the review of the literature suggest that patients carrying chromosomal anomalies might have a higher risk for photosensitivity when compared to the normal population. In these patients, PPR might occur early in life, persist into adulthood, and is commonly inscribed in more polymorphic electroclinical patterns.

Adolescent↗

Loss-of-function mutation of the AF9/MLLT3 gene in a girl with neuromotor development delay, cerebellar ataxia, and epilepsy.

The human AF9/MLLT3 gene is a common fusion partner for the MLL gene in translocations t(9;11)(p22;q23) associated with acute myeloid leukemia and acute lymphocytic leukemia. The exact function of the gene is still unknown, although a mouse knock-out model points to a role as a controller of embryo patterning. We report the case of a constitutional translocation t(4;9)(q35;p22) disrupting the AF9/MLLT3 gene in a girl with neuromotor development delay, cerebellar ataxia and epilepsy. Array-CGH analysis at 1 Mbase resolution did not reveal any additional deletions/duplications. We hypothesize a loss-of-function mutation of the AF9/MLLT3 gene, and a possible role for the FAT gene on chromosome 4, in the genesis of the proband's severe neurological phenotype.

Base Sequence↗

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↗

Non-progressive leukoencephalopathy with bilateral anterior temporal cysts: a case report and review of the literature.

A newly described disease is characterized by anterior bilateral temporal lobe cysts associated with multilobar leukoencephalopathy and a non-progressive clinical course. We report a patient with bilateral anterior temporal lobe cystic changes associated with a non-progressive neurological disorder, microcephaly, spasticity, mental retardation, and sensorineural deafness. From the literature, 12 other patients have shown a similar phenotype. The common neuroradiological findings in these patients have been bilateral anterior temporal lobe cystic changes and non-progressive leukoencephalopathy. By contrast, variability in the clinical phenotype has been observed, ranging from severe neuromotor handicap with mental retardation and microcephaly to spasticity in the lower limbs associated with normal cognitive function. The pathological basis of the defect remains to be defined.

Central Nervous System Cysts↗

Post-ictal circulating levels of allopregnanolone in children with partial or generalized seizures.

INTRODUCTION: Allopregnanolone (3alpha-hydroxy-5alpha-pregnan-20-one) is a neurosteroid with a potent modulating activity on the gamma-aminobutyric acid (GABA)(a) receptor complex. It plays a key role in the epileptogenesis of partial seizures. Serum allopregnanolone concentrations significantly increase in the postcritical phase. In the present study we investigated the post-ictal serum allopregnanolone levels in children with partial seizures and generalized seizures, respectively. PATIENTS AND METHODS: Three groups of subjects were included in the study. Group 1 consisted of 18 children affected by complex partial seizures. Group 2 consisted of 11 children presenting with generalized epilepsy. Group 3 consisted of 20 healthy age-matched subjects. Serum allopregnanolone levels were assayed in the inter-ictal phase and within 30 min after an epileptic event. RESULTS: The data we obtained suggest that circulating allopregnanolone level significantly increases in the post-ictal phase. However, we found no significant differences in the post-ictal serum allopregnanolone concentrations between patients with partial seizures and those with generalized seizures. CONCLUSIONS: Further studies are needed to establish if allopregnanolone is a reliable circulating marker of epileptic seizures. However, our observations seem to indicate that post-ictal circulating allopregnanolone level is not useful in differentiating focal and generalized epilepsy events.

Anesthetics↗

Childhood absence epilepsy: evolution and prognostic factors.

PURPOSE: To evaluate how diagnostic criteria influence remission rates for patients with childhood absence epilepsy (CAE) and to assess clinical and EEG parameters as predictors of outcome. METHODS: One hundred nineteen patients were diagnosed with CAE, according to International League Against Epilepsy (ILAE) classification criteria. They were subsequently evaluated according to stricter diagnostic criteria. Sixty-two subjects fulfilled these criteria as group 2; 57 did not and constituted group 1. Diagnostic parameters that prevented patients of group 1 from entering group 2, and variables such as sex, familial history of generalized epilepsy, and personal history of febrile convulsions also were tested as prognostic factors for terminal remission. RESULTS: Compared with those in group 1, patients of group 2 had significantly higher rates of seizure control (95% vs. 77%), higher rates of terminal remission (82% vs. 51%), fewer generalized tonic-clonic seizures (8% vs. 30%), and shorter mean periods of treatment (2.2 vs. 3.8 years). Significantly fewer patients were receiving polytherapy in group 2 than in group 1 (11% vs. 47%), and fewer patients had seizure relapses at antiepileptic drug discontinuation (0 vs. 22%). CONCLUSIONS: Remission rates of patients with CAE are greatly influenced by the classification criteria used for selection. Stricter diagnostic criteria allow the definition of a homogeneous group of patients with excellent prognosis. Factors predicting unfavorable prognosis were generalized tonic-clonic seizures in the active stage of absences, myoclonic jerks, eyelid myoclonia or perioral myoclonia, and EEG features atypical for CAE.

Adolescent↗

Efficacy and safety of topiramate in refractory epilepsy of childhood: long-term follow-up study.

This study aimed to evaluate the long-term efficacy and safety of topiramate in treating children with drug-resistant epilepsy. A multicentric, retrospective, open-label, add-on study was undertaken of 277 children (mean age 8.4 years; range 12 months to 16 years) affected by drug-resistant epilepsy. The efficacy was rated according to the seizure types and epilepsy syndrome. After a mean period of 27.5 months of treatment (range 24-61 months), 11 patients (4%) were seizure free and 56 (20%) had more than 50% reduction in seizure frequency. The efficacy of topiramate treatment was noted in localization-related epilepsy and in generalized epilepsy. In addition, in a group of 114 patients, we compared the initial efficacy (evaluated after a mean of 9 months of follow-up) and the retention at a mean of 30 months of topiramate with regard to loss of efficacy (defined as the return to the baseline seizure frequency). Fifty-five (48%) of 114 patients were initial responders. The retention at a mean of 30 months was 23 of 114 patients (20%), 4 of whom (3.5%) were still seizure free. A loss of efficacy occurred in 32 of the 55 initial responders (58%). It was prominent in patients with generalized epilepsy, such as symptomatic infantile spasms and Lennox-Gastaut syndrome, as well as in those with Dravet syndrome. By contrast, a well-sustained topiramate efficacy was noted among patients with localization-related epilepsy. Globally, adverse events were observed in 161 patients (58%) and were mainly represented by weight loss, hyperthermia, sedation, and nervousness, which, in most cases, disappeared after slowing titration or reducing the dosage of the drug. In conclusion, the present long-term study confirms that topiramate represents a useful drug effective in a wide range of seizures and epilepsy syndromes. Moreover, preliminary data seem to suggest that the efficacy of topiramate, when evaluated in the long-term perspective, is more sustained in localization-related epilepsy than in generalized epilepsy.

Adolescent↗

Craniofacial dyssynostosis: case report and review.

Craniofacial dyssynostosis (CFD) is a rare disorder related to premature closure of the lambdoid suture and the posterior part of the sagittal suture. Epilepsy, mental retardation, abnormalities of the corpus callosum, and short stature have been reported. We studied a patient with CFD, hydronephrosis, and partially empty sella turcica; the latter two features are reported for the first time. We discuss the brain anomalies and their neurologic sequelae, which are part of the CFD phenotype.

Abnormalities, Multiple↗

Ethylmalonic encephalopathy is caused by mutations in ETHE1, a gene encoding a mitochondrial matrix protein.

Ethylmalonic encephalopathy (EE) is a devastating infantile metabolic disorder affecting the brain, gastrointestinal tract, and peripheral vessels. High levels of ethylmalonic acid are detected in the body fluids, and cytochrome c oxidase activity is decreased in skeletal muscle. By use of a combination of homozygosity mapping, integration of physical and functional genomic data sets, and mutational screening, we identified GenBank D83198 as the gene responsible for EE. We also demonstrated that the D83198 protein product is targeted to mitochondria and internalized into the matrix after energy-dependent cleavage of a short leader peptide. The gene had previously been known as "HSCO" (for hepatoma subtracted clone one). However, given its role in EE, the name of the gene has been changed to "ETHE1." The severe consequences of its malfunctioning indicate an important role of the ETHE1 gene product in mitochondrial homeostasis and energy metabolism.

Amino Acid Sequence↗

Facial hemangioma and malformation of the cortical development: a broadening of the PHACE spectrum or a new entity?

Facial hemangioma is usually isolated but its association with craniocervical arterial anomalies and structural brain malformations is well known. The acronym PHACE syndrome (posterior fossa malformation, facial hemangiomas, arterial anomalies, cardiac/aortic anomalies, and eye abnormalities) has been used to indicate that disorder in which brain anomalies are mainly represented by the Dandy-Walker malformation. We report on a 10-month-old boy affected by facial hemangioma and a complex cortical dysplasia located in the left frontal region. The lesion was characterized by a deeply infolding pachygyric cortex and a band of gray matter lining the wall of the lateral ventricle. The entire left cerebral hemisphere appeared hypoplastic. No anomalies of the posterior fossa structures or cardiac/aortic malformations were present. An overlapping clinical/pathological pattern was previously reported in another patient with facial hemangioma and cerebrovascular anomalies. These observations seem to indicate that the facial hemangiomas may be associated with disorders of the cortical development.

Abnormalities, Multiple↗

Hot water epilepsy and focal malformation of the parietal cortex development.

Hot water epilepsy (HWE) refers to a specific type of reflex epilepsy precipitated by the stimulus of bathing in hot water. HWE is considered to be a geographically specific epileptic syndrome since it mainly occurs in the Indian community. Spontaneous seizures may also occur later in life. The seizure pattern includes complex partial attacks. Although the pathogenesis of HWE is still unknown, temporal lobe has been thought to take part in the epileptogenesis. This paper reports on a 4-year-old girl who, at the age of 6 months, experienced complex partial seizures triggered by bathing in hot water. Non-provoked seizures intercritical EEG showed isolated spikes and spike-and-waves in the left parietal region. Brain MRI detected a left parietal focal cortical dysplasia. This is the second patient with HWE in whom a cortical malformation has been observed. The observation present here and data reported in the literature seem to indicate that the sensory cortex might also be involved in triggering seizures precipitated by a bath in hot water. Moreover, the authors believe that MRI examination should be considered for this group of patients.

Anticonvulsants↗

Epilepsy and electroencephalographic findings in pericentric inversion of chromosome 12.

Epilepsy, together with mental retardation, represents a common manifestation of chromosomal aberrations. Specific electroencephalographic (EEG) and epileptic patterns have been described in several chromosomal disorders, such as Angelman's syndrome, Miller-Dieker syndrome, Wolf-Hirschhorn syndrome, and ring 20 syndrome. A peculiar electroclinical pattern has also been identified in trisomy 12p syndrome. We report three patients with a pericentric inversion of chromosome 12, with breakpoints localized to p11-q13 and affected by epilepsy or EEG anomalies. Two suffered from epilepsy, which, in the clinical course, was mainly characterized by complex partial seizures with a semiology related to the temporal lobe. In one patient, myoclonic absences, head drop, and massive jerky attacks were also present. In both patients, generalized 3 Hz bursts were registered, together with multifocal and focal paroxysmal activity, which were most prominent in the temporoparietal and temporal areas, respectively. In the other patient, who had no epilepsy, EEG showed bioccipital paroxysmal activity. In all patients, the clinical picture was characterized by the presence of moderate mental retardation and behavioral disorders. The incidence of epilepsy or EEG anomalies among patients with a pericentric inversion of chromosome 12 remains to be ascertained. However, the present study confirms that chromosome 12 anomalies can be associated with epilepsy. Although myoclonic absence-like episodes can occasionally be part of the epileptic phenotype, the electroclinical pattern in pericentric inversion of chromosome 12 seems to be more polymorphic when compared with that observed in trisomy 12p syndrome.

Adult↗

Medial temporal lobe dysgenesis in Muenke syndrome and hypochondroplasia.

Hypochondroplasia (HCH) and Muenke syndrome (MS) are caused by mutations on FGFR3 gene. FGFR3 is known to play a role in controlling nervous system development. We describe the clinical and neuroradiological findings of the first two patients, to our knowledge, affected by HCH and MS, respectively, in whom bilateral dysgenesis of the medial temporal lobe structures has been observed. In both patients diagnosis was confirmed by molecular analysis. They were mentally normal and showed similarities in early-onset temporal lobe-related seizures. In both patients EEG recorded bilateral temporal region discharges. MRI detected temporal lobe anomalies with inadequate differentiation between white and gray matter, defective gyri, and abnormally shaped hippocampus.

Abnormalities, Multiple↗

Linear scleroderma associated with progressive brain atrophy.

Linear scleroderma (LS) is characterized by scleroatrophic lesions affecting limbs and legs, unilaterally. Neurological involvement may be associated with ipsilateral facial and skull involvement in disorders referred to clinically as LS 'en coup de sabre', and Parry-Romberg syndrome. We report a child with LS presenting with a severe neurological disorder characterized by epilepsy, progressive mental deterioration and a rapid process of atrophy involving the ipsilateral cerebral hemisphere, but not associated with an overlying facial structure involvement. Functional brain studies showed a reduction in the diameter of the left internal carotid and of the left middle cerebral artery. Our observations suggest that neuroimaging studies should be considered in all patients with linear scleroderma, and such studies become necessary when neurological symptoms occur.

Brain Diseases↗

Schinzel-Giedion syndrome: a further cause of West syndrome.

Schinzel-Giedion syndrome (SGS) is a rare disorder with a likely autosomal recessive pattern of inheritance which is characterized by several facial dysmorphisms, midface hypoplasia, multiple skeletal anomalies including short and sclerotic skull base, short neck, and post-axial polydactyly. Cardiac and urogenital malformations are also present. Thirty-three cases have been described so far. We report on a boy affected by SGS in whom a long-term EEG follow-up showed a progressive deterioration of the background bioelectric activity ending, at the age of 19 months, with a hypsarrhythmic pattern clinically correlated with severe and refractory infantile spasms. EEG deterioration and neuroradiological findings, which showed progressive brain atrophy, confirm the neurodegenerative nature of SGS. We also re-evaluated all the published cases and found that 33% of patients with SGS experienced neonatal seizures and another 25% developed West syndrome in the following months. The seizures appeared extremely refractory to several anticonvulsive treatments. In conclusion, we believe that SGS should be included among the causes of secondary West syndrome.

Abnormalities, Multiple↗

Inter-ictal and post-ictal circulating levels of allopregnanolone, an anticonvulsant metabolite of progesterone, in epileptic children.

Allopregnanolone belongs to a group of neuroactive steroid hormones, or neurosteroids, synthesized and acting within the brain and is as a potent endogenous positive modulator of GABA(A) receptor complex. Administration of allopregnanolone protects rats against pentylentetrazol, bicuculline, kainic acid, and picrotoxin-induced seizures. We investigated serum allopregnanolone levels in children with active epilepsy at pubertal Tanner's stage I (n=52). Blood specimens were collected at least 12 h after a seizure (inter-ictal). In a subgroup of patients (n=11), specimens were also collected within 30 min from a seizure attack (post-ictal). Healthy age-matched children (n=18) served as controls. Serum allopregnanolone was measured by radioimmunoassay using a polyclonal antiserum. The inter-ictal serum allopregnanolone levels in the epileptic children were not statistically different from those detected in the control group, whereas post-ictal levels were significantly higher than the inter-ictal ones (P=0.0001). In this subgroup of patients allopregnanolone levels decreased to the basal values during the following 12 h. Serum allopregnanolone levels may therefore reflect changes in neuronal excitability, and allopregnanolone appears to be a reliable circulating marker of epileptic seizures. It is possible that increased post-ictal serum levels of allopregnanolone may play a role in modulating neuronal excitability and may represent an endogenous mechanism of seizure control.

Anticonvulsants↗