Biomedical subjects

Sabrina Signorini

Publications and source records attributed to Sabrina Signorini.

6 recordsLinked to original sources

PubMed2025

COL4A1 and COL4A2-related disorders: Clinical features, diagnostic guidelines, and management.

PURPOSE: Collagen type 4 alpha 1 (COL4A1) and alpha 2 (COL4A2) chains, encoded by COL4A1 and COL4A2, are essential for basement membrane integrity, contributing to structural stability and cell regulation. Pathogenic variants in these genes cause a spectrum of autosomal dominant and, more rarely, autosomal recessive disorders, which are collectively known as COL4A1/A2-related disorders. These multisystem disorders can include neurologic, ophthalmologic, renal, and other organ system pathology and vary widely in symptoms, complicating diagnosis and management. METHODS: Using a modified eDelphi method, we obtained consensus from international experts across medical subspecialties on the evaluation and management of COL4A1/A2-related disorders, with consensus set at ≥70% agreement. RESULTS: Consensus was achieved on recommendations for evaluating and managing these conditions. CONCLUSION: Genetic testing and counseling are advised for individuals showing symptoms of COL4A1/A2-related disorders and for at-risk relatives. Given the complexity and rarity of these disorders, management requires a multidisciplinary approach informed by current understanding of disease mechanisms. Recommended care includes neurological and ophthalmological imaging and monitoring of cardiovascular and renal function. Ongoing research is critical to uncover genotype-phenotype links and potential modifiers, with clinical research participation encouraged to advance knowledge and treatments.

Humans↗

PubMed2006

Mutations in CEP290, which encodes a centrosomal protein, cause pleiotropic forms of Joubert syndrome.

Joubert syndrome-related disorders (JSRD) are a group of syndromes sharing the neuroradiological features of cerebellar vermis hypoplasia and a peculiar brainstem malformation known as the 'molar tooth sign'. We identified mutations in the CEP290 gene in five families with variable neurological, retinal and renal manifestations. CEP290 expression was detected mostly in proliferating cerebellar granule neuron populations and showed centrosome and ciliary localization, linking JSRDs to other human ciliopathies.

Animals↗

PubMed2006

Changes in the optic disc excavation of children affected by cerebral visual impairment: a tomographic analysis.

PURPOSE: To obtain quantitative data on the optic disc excavation in children affected by cerebral visual impairment (CVI) by using the Heidelberg Retinal Tomograph (HRT)-II (Heidelberg Engineering, Heidelberg, Germany). METHODS: A total of 24 subjects affected by CVI (mean age, 7.28 years) were examined: 16 in alert conditions and 8 under general anesthesia. The following parameters of the optic nerve head were examined: disc area, cup area, rim area, cup volume, rim volume, cup-to-disc area ratio, mean cup depth, maximum cup depth, cup shape measure, and mean retinal nerve fiber layer (RNFL) thickness. The tomographic results in children with CVI were compared with those of 88 normal, alert subjects of similar age. RESULTS: The optic disc of patients with CVI appeared smaller than normal. Its excavation, however, was more pronounced. Several tomographic parameters were altered in CVI-affected subjects. Statistical analysis showed a highly significant probability in cup-to-disc area ratio (P < 0.01, both eyes), rim area (P < 0.01, both eyes), cup shape measure (P < 0.01, right eye; P < 0.01, left eye), and mean RNFL thickness (P < 0.01, right eye; P < 0.01, left eye). A novel observation was temporal atrophy of the optic nerve head in CVI. CONCLUSIONS: The data provide a tridimensional, objective evaluation of the anatomic alterations of the optic nerve head in children with CVI. Furthermore, tomographic standards for optic disc shape in normal children are set for the first time.

Brain Ischemia↗

PubMed2005

Cognitive competence at the onset of West syndrome: correlation with EEG patterns and visual function.

The aim of this study was to evaluate cognitive development at the onset of West syndrome (WS) with regard to electroencephalogram (EEG) patterns and visual function. Twenty-five patients (14 males, 11 females) at the onset of spasms (T0) in WS and 2 months later (T1) underwent a full clinical evaluation, including neuroimaging, cognitive assessment, video-EEG, and visual function. Mean age of the patients at spasm onset was 5.9 months (SD 2.5; range 2 to 13mo). Cognitive development, assessed with Griffiths Mental Development Scales (GMDS), was generally impaired at T0 and was significantly related to visual function (p<0.001) at both T0 and T1. In general, there was a specific major impairment in the eye-hand coordination scale of the GMDS which tended to disappear after 2 months in less severe cases. At the onset of spasms, sleep EEG organization seemed to be better related to cognitive abilities than awake hypsarrhythmia. These results support a close link between visual function and cognitive competence in WS and provide additional information to improve the understanding of possible mechanisms underlying cognitive impairment.

Child Development↗

PubMed2004

Topiramate efficacy in an infant with partial seizures refractory to conventional antiepileptic drugs.

Many studies showed that Topiramate (TPM) may be a useful drug in a wide spectrum of childhood epilepsies. We report a 3-month-old female with stormy onset of secondarily generalized partial seizures. She showed a high seizure frequency and a progressive worsening electroencephalogram (EEG), despite standard antiepileptic drugs administration. TPM succeeded in controlling seizures, even after the other drugs were discontinued. This case suggests that TPM may represent a good choice for the treatment of partial seizures refractory to conventional drugs in infants.

Anticonvulsants↗

PubMed2004

Visual function in infants with West syndrome: correlation with EEG patterns.

PURPOSE: Several studies have reported behavioral and electrophysiological evidence of visual impairment during the active stage of West syndrome. The underlying mechanisms are, however, poorly understood, and little has been reported about the correlation between visual impairment, EEG patterns, and brain lesions. The aim of the study was to assess visual function at the onset of spasm and 2 months thereafter and relate visual findings to brain lesions and EEG features. METHODS: Twenty-five infants with West syndrome were enrolled and studied with (a) a full clinical assessment including a battery of tests specifically designed to assess visual function, (b) a video-polygraphic study, and (c) brain magnetic resonance imaging (MRI). Besides brain neuroimaging and EEG comparison with visual function, an intra-EEG analysis was performed to investigate the possible relation of EEG patterns to fluctuating visual behavior (fixation and following). RESULTS: Twenty-two children had at least one abnormal result on one or more of the tests assessing visual function at T0. Visual impairment at the spasm onset was related to the sleep disorganization rather than to the hypsarrhythmic pattern in awake EEG. After 2 months, both EEG features become significantly linked to visual function. Visual function improved in several cases after 2 months, in parallel with the seizure regression. No relation was found between EEG patterns and fluctuating visual behavior. CONCLUSIONS: The study supplies new evidence of the involvement of visual function in West syndrome. The presence of abnormal visual findings in infants without lesions on brain MRI suggests that visual abnormalities are due not only to brain injury but also to epileptic disorder per se. New insight is also provided into the possible mechanisms underlying clinical and EEG abnormalities.

Brain↗