The ring 14 (r14) syndrome is a rare condition, whose precise clinical and genetic characterization is still lacking. We analyzed a total of 20 patients with r14 and another 9 patients with a linear 14q deletion. The ring was complete, with no apparent loss of chromosome material, in 6 cases; a terminal 14q deletion, varying in size from 0.65 to 5 Mb, was detected in the remaining 14 cases. Deleted ring chromosomes were 70% paternal and 30% maternal. UPD (14) was never detected. With respect to the linear 14q deletions, three were proximal, varying in size from 4 to 7.2 Mb, and six distal, varying in size from 4.8 to 20 Mb. The majority of the linear deletions were also of paternal origin, and UPD (14) was excluded in all cases. Clinically, the r14 syndrome was characterized by a recognizable phenotype, consisting of shortness of stature, a distinctive facial appearance, microcephaly, scoliosis, and ocular abnormalities, which included abnormal retinal pigmentation, strabismus, glaucoma, and abnormal macula. All patients except one had mental retardation. Drug-resistant epilepsy was another highly consistent finding. Aggressive and hyperactive behavior was noted in about half of the patients. Based on genotype-phenotype correlations, we could deduce that retinal abnormalities, epilepsy, microcephaly, and mental retardation map within the proximal 14q11.2-q12 region. Likewise, behavior disorders and scoliosis could be assigned to the 14q32 region.

West syndrome (WS) is characterized by infantileonset flexor and extensor spasms, an EEG pattern of a high amplitude with asynchronous activity of spikes and theta/delta waves (hypsarrhythmia), and impaired psychomotor development. 1 In about 70%-80% of the children, WS develops as a consequence of metabolic disorders or brain lesions, but in many cases the etiology is unknown. 2Methods. See also appendices e-1 (Methods) and e-2 (case descriptions) on the Neurology ® Web site at www.neurology.org. We screened by high-resolution comparative genomic hybridization (array-CGH) 38 (20 male, 18 female) consecutively collected patients with WS of unknown etiology (table e-1). Diagnosis was based on 1) absence of prenatal or postnatal etiologic factors, 2) normal development and absence of neurologic abnormalities before the onset, and 3) normal laboratory and MRI findings at onset.

No abstract

Cerebral cavernous malformations (CCMs) are vascular abnormalities that may cause seizures, intracerebral haemorrhages, and focal neurological deficits. Familial form shows an autosomal dominant pattern of inheritance with incomplete penetrance and variable clinical expression. Three genes have been identified causing familial CCM: KRIT1/CCM1, MGC4607/CCM2, and PDCD10/CCM3. Aim of this study is to report additional PDCD10/CCM3 families poorly described so far which account for 10-15% of hereditary cerebral cavernous malformations. Our group investigated 87 consecutive Italian affected individuals (i.e. positive Magnetic Resonance Imaging) with multiple/familial CCM through direct sequencing and Multiplex Ligation-Dependent Probe Amplification (MLPA) analysis. We identified mutations in over 97.7% of cases, and PDCD10/CCM3 accounts for 13.1%. PDCD10/CCM3 molecular screening revealed four already known mutations and four novel ones. The mutated patients show an earlier onset of clinical manifestations as compared to CCM1/CCM2 mutated patients. The study of further families carrying mutations in PDCD10/CCM3 may help define a possible correlation between genotype and phenotype; an accurate clinical follow up of the subjects would help define more precisely whether mutations in PDCD10/CCM3 lead to a characteristic phenotype.

No abstract

Polysilicon thin-film transistors are of great interest for their application in large area microelectronics and especially for their circuit applications. A successful circuit design requires a proper understanding of the electrical characteristics and in the present work some specific aspects related to the hot-carrier induced electrical instabilities are presented. In particular, generation of interface states near the drain junction occurs when the devices are operated for a prolonged time in the so-called kink regime. In the present work we show both experimentally and by numerical simulations how the presence of such interface states affects the electrical characteristics. Furthermore, a novel simple method is proposed to extract, from the analysis of the sheet conductances, the interface state density. The hot-carrier induced interface state density relative to the present devices shows a featureless continuous distribution. Reduction of the generated interface states is observed if trapped holes are annihilated by electron capture. These results suggest that the interface states are induced by the presence of trapped holes, in agreement with similar data reported for c-Si metal–oxide–semiconductor structures.

No abstract

We report a near-edge x-ray absorption spectroscopy (NEXAFS) study of the C K-edge of C 60 molecules interacting with Si(100) and Si(111) surfaces. Annealing the C 60/Si systems at 1050 K induces fullerene fragmentation and leads to SiC nucleation. Tuning the probing depth and studying polarization dependence, the NEXAFS results shed light on the evolution of the molecular states after thermal treatment, up to the fullerene fragmentation and SiC formation. The NEXAFS spectra of a single layer of C 60 deposited at 670 K onto both surfaces show a strong C 60-substrate interaction. A polarization dependence of the spectra can be detected; this behaviour is similar to the results obtained on C 60 covalently chemisorbed on Al surfaces. We find, for both substrates, that fullerene fragmentation starts at the C-Si interfaces, involving the C atoms lying close to the Si substrate, implying an increase of the number of C-Si bonds at the fragmentation stage