RESUMEN
Bi-allelic loss-of-function variants in genes that encode subunits of the adaptor protein complex 4 (AP-4) lead to prototypical yet poorly understood forms of childhood-onset and complex hereditary spastic paraplegia: SPG47 (AP4B1), SPG50 (AP4M1), SPG51 (AP4E1) and SPG52 (AP4S1). Here, we report a detailed cross-sectional analysis of clinical, imaging and molecular data of 156 patients from 101 families. Enrolled patients were of diverse ethnic backgrounds and covered a wide age range (1.0-49.3 years). While the mean age at symptom onset was 0.8 ± 0.6 years [standard deviation (SD), range 0.2-5.0], the mean age at diagnosis was 10.2 ± 8.5 years (SD, range 0.1-46.3). We define a set of core features: early-onset developmental delay with delayed motor milestones and significant speech delay (50% non-verbal); intellectual disability in the moderate to severe range; mild hypotonia in infancy followed by spastic diplegia (mean age: 8.4 ± 5.1 years, SD) and later tetraplegia (mean age: 16.1 ± 9.8 years, SD); postnatal microcephaly (83%); foot deformities (69%); and epilepsy (66%) that is intractable in a subset. At last follow-up, 36% ambulated with assistance (mean age: 8.9 ± 6.4 years, SD) and 54% were wheelchair-dependent (mean age: 13.4 ± 9.8 years, SD). Episodes of stereotypic laughing, possibly consistent with a pseudobulbar affect, were found in 56% of patients. Key features on neuroimaging include a thin corpus callosum (90%), ventriculomegaly (65%) often with colpocephaly, and periventricular white-matter signal abnormalities (68%). Iron deposition and polymicrogyria were found in a subset of patients. AP4B1-associated SPG47 and AP4M1-associated SPG50 accounted for the majority of cases. About two-thirds of patients were born to consanguineous parents, and 82% carried homozygous variants. Over 70 unique variants were present, the majority of which are frameshift or nonsense mutations. To track disease progression across the age spectrum, we defined the relationship between disease severity as measured by several rating scales and disease duration. We found that the presence of epilepsy, which manifested before the age of 3 years in the majority of patients, was associated with worse motor outcomes. Exploring genotype-phenotype correlations, we found that disease severity and major phenotypes were equally distributed among the four subtypes, establishing that SPG47, SPG50, SPG51 and SPG52 share a common phenotype, an 'AP-4 deficiency syndrome'. By delineating the core clinical, imaging, and molecular features of AP-4-associated hereditary spastic paraplegia across the age spectrum our results will facilitate early diagnosis, enable counselling and anticipatory guidance of affected families and help define endpoints for future interventional trials.
Asunto(s)
Complejo 4 de Proteína Adaptadora/genética , Cuerpo Calloso/diagnóstico por imagen , Imagen por Resonancia Magnética/tendencias , Paraplejía Espástica Hereditaria/diagnóstico por imagen , Paraplejía Espástica Hereditaria/genética , Adolescente , Adulto , Niño , Preescolar , Estudios de Cohortes , Estudios Transversales , Femenino , Humanos , Lactante , Imagen por Resonancia Magnética/métodos , Masculino , Persona de Mediana Edad , Sistema de Registros , Adulto JovenRESUMEN
BACKGROUND: Up to one third (3-33%) oral squamous cell carcinomas develop from potentially malignant lesions. Most common potentially malignant lesions (PML) are leukoplakia and lichen planus. It is very important to diagnose PML at early stage to prevent malignant transformation of lesion. Survivin is a smallest member of the inhibitor of apoptosis (IAP) family of proteins. Survivin plays an important role in apoptosis regulation. High expression of survivin is an early event during oral carcinogenesis and it acts as a tool for the identification of precancerous lesions at higher risk of progression into invasive carcinoma. The aim of the study was to evaluate the expression of survivin in oral leukoplakia, oral lichen planus. METHODS: Fifteen patients with oral lichen planus and 15 patients with oral leukoplakia were selected as subjects for the present study and 15 patients with normal oral mucosa were selected as controls and were evaluated for expression of survivin. All sections were H&E stained and were studied immunohistochemically for the expression of survivin. RESULTS: Expression of survivin was evaluated based on the percentage of cells expressing surviving, as well as grading. Significant survivin expression was detected in oral leukoplakia and oral lichen planus (P<0.001). CONCLUSIONS: Expression of survivin in potentially malignant lesions indicates the potential risk of malignant transformation.