Lipofuscinosis neuronal ceroidea tipo 2 (CLN2): primer caso diagnosticado en Panamá, causado por una variante patogénica del gen TPP1 producida por una mutación sin sentido

Se presenta el caso clínico de un paciente con Lipofuscinosis Neuronal Ceroidea tipo 2 (CLN2), condición genética producida por mutaciones en el gen TPP1. La CLN2 es una Enfermedad de Depósito Lisosomal (LSD), grupo de trastornos genéticos que forman parte de los Errores Innatos del Metabolismo, en los que se acumula un sustrato que no puede ser degradado a nivel de los lisosomas por la deficiencia en una enzima. En el caso de la CLN2, este déficit enzimático ocasiona un cuadro de deterioro neurológico acelerado con epilepsia refractaria, tratándose del primer caso descrito en la República de Panamá a la fecha. Esta condición es una enfermedad rara, y este reporte muestra la importancia de la necesidad de considerar la realización de paneles de diagnóstico genético cuando se presenta una epilepsia de difícil manejo en infantes. (provisto por Infomedic International)

The clinical case of a patient with Ceroid Neuronal Lipofuscinosis type 2 (CLN2), a genetic condition produced by mutations in the TPP1 gene, is presented. CLN2 is a Lysosomal Deposition Disease (LSD), a group of genetic disorders that are part of the Inborn Errors of Metabolism, in which a substrate accumulates that cannot be degraded at the level of the lysosomes due to a deficiency in an enzyme. In the case of CLN2, this enzymatic deficit causes an accelerated neurological deterioration with refractory epilepsy, being the first case described in the Republic of Panama to date. This condition is a rare disease, and this report shows the importance of the need to consider genetic diagnostic panels when a difficult-to-manage epilepsy occurs in infants. (provided by Infomedic International)

A Case Report on the Challenging Diagnosis of Neuronal Ceroid Lipofuscinosis Type 2 (CLN2)

Abstract Neuronal ceroid lipofuscinoses (NCLs), also referred as "Batten disease", are a group of thirteen rare genetic conditions, which are part of the lysosomal storage disorders. CLN type 2 (CLN2) is caused by the deficient activity of the tripeptidyl peptidase I (TPP1) enzyme, encoded by the TPP1 gene, most frequently leading to the classic late infantile phenotype. Nearly 140 CLN2-causing mutations have been described. In this case report, we describe the identification of a new disease-causing mutation and highlight the importance of appropriate laboratory investigation based on clinical suspicion. The collection of dried blood spots (DBS) on filter paper, which is a convenient sample, can be used to measure the TPP1 enzyme activity and detect CLN2-related mutations. Since the biochemical and genetic diagnoses are possible and as the disease progression is fast and the therapeutic window is short, the investigation of CLN2 should be always considered when this diagnostic hypothesis is raised in order to enable the patients to benefit from the specific pharmacological treatment.

TPP1 confers telomere end protection by recruiting Pot1a and Pot1b to telomeres / 第三军医大学学报

Objective To characterize the effects of TPP1 knockdown on Pot1a and Pot1b localization at telomeres and on the telomere end protection.Methods Knockdown of endogenous TPP1 in mouse embryonic fibroblasts(MEFs) with the retrovirus vector encoding shRNA targeting TPP1,IF/PNA-FISH was performed to determine the localization of Pot1a and Pot1b at telomeres,and TdT-FITC was applied to characterize the effects on the function of telomere end protection,cellular senescence was analyzed by SA-beta gal staining,and phosphorylated p53ser18 and p21 were examined by Western blotting.Results Pot1a and Pot1b were unable to localize at telomeres in about 65% of MEFs with TPP1 knockdown,while that was found in less than 5% of MEFs without TPP1 knockdown(t=10.96,P