Search

Background: Neuronal ceroid lipofuscinosis (NCL) is a hereditary lysosomal storage disease with progressive brain neurodegeneration. Mutations in ceroid lipofuscinosis neuronal protein 5 (CLN5) cause CLN5 disease, a severe condition characterized by seizures, visual failure, motor decline, and progressive cognitive deterioration. This study aimed to identify causative gene variants in Pakistani consanguineous families diagnosed with NCL., Methods: After a thorough clinical and neuroradiological characterization, whole exome sequencing (WES) was performed in 3 patients from 2 unrelated families. Segregation analysis was subsequently performed through Sanger sequencing ANALYSIS: WES led to the identification of the 2 novel homozygous variants c.925_926del, (p.Leu309AlafsTer4) and c.477 T > C, (p.Cys159Arg)., Conclusion: In this study, we report two novel CLN5 cases in the Punjab region of Pakistan. Our observations will help clinicians observe and compare common and unique clinical features of NCL patients, further improving our current understanding of NCL., (Copyright © 2020 The Authors. Published by Elsevier B.V. All rights reserved.)

Aim: Neuronal ceroid lipofuscinosis (NCLs) are the most common neurodegenerative disorders, with global incidence of 1 in 100,000 live births. NCLs affect central nervous system, primarily cerebellar and cerebral cortices. Juvenile neuronal ceroid lipofuscinosis (JNCL), also known as Batten disease, is the most common form of NCLs. JNCL is primarily caused by pathogenic mutations in CLN3 gene, which encodes a transporter transmembrane protein of uncertain function. The 1.02 kb deletion is the most common mutation in CLN3 that results in frame shift and a premature termination leading to nonfunctional protein. Here, we invetigated a large consanguineous family consisting of four affected individuals with clincal symptoms suggestive of Juvenile neuronal ceroid lipofuscinosis. Materials and methods: We conducted clinial and radilogical investigation of the family and performed NGS based Gene Panel sequencing comprising of five hundred and forty five candidate genes to characterize it at genetic level. Results: We identified a novel homozygous c.181_183delGAC mutation in the CLN3 gene seggregating witht the disorder in the family. The mutation induces in-frame deletion, deleting one amino acid (p.Asp61del) in CLN3 protein. The deleted amino acid aspartic acid plays an important role as general acid in enzymes active centers as well as in maintaining the ionic character of proteins. Conclusion: Our finding adds to genetic variability of Juvenile neuronal ceroid lipofuscinosis associated with CLN3 gene and a predicted CLN3 protein interacting domain site.

The neuronal ceroid lipofuscinoses (NCLs), the most common neurodegenerative diseases in children, are characterised by storage of autofluorescent material that has a characteristic ultrastructure. We report two families with variant late infantile NCL, both originating from Pakistan. Probands from both families were homozygous for the same mutation (c.316dupC) but had variable pathology to that currently thought to be typical for CLN6 disease, late infantile variant. The observed pathology of one proband resembled condensed fingerprints, previously described in late infantile CLN7 and CLN8 diseases, and pathology from the second proband was thought to be absent even after repeated skin biopsy, but observed after review. This mutation is the most common NCL mutation in families originating from Pakistan and could be prioritised for testing. Finally, this report contains the first prenatal diagnosis for late infantile CLN6 disease, initially made on the basis of EM and now confirmed by mutation analysis., (Copyright © 2013 European Paediatric Neurology Society. Published by Elsevier Ltd. All rights reserved.)

The neuronal ceroid lipofuscinoses (NCLs) are a group of inherited lysosomal storage diseases and the prototype of childhood onset neurodegenerative disorders. To date, 10 NCL entities (CLN1-CLN10) are known and characterized by accumulation of autofluorescent storage material, age of onset and clinical symptoms. CLN8 was first identified as the causative gene for a late-onset form with progressive epilepsy and mental retardation in Finnish patients. In addition, CLN8 phenotypes were described in Turkish, Israeli and Italian patients with a more rapid progression of visual loss, epilepsy, ataxia and mental decline. Here, we report the first mutations in German (c.611G>T) and Pakistani (c.709G>A) patients. Our findings confirm previous assumptions that the CLN8 variant can occur in many ethnic groups. So far, large CLN gene deletions are only known for the CLN3 gene. Here, we also describe a novel, large CLN8 gene deletion c.544-2566_590del2613 in a Turkish family with a slightly more severe phenotype. Our data indicate that patients with clinical signs of late infantile NCL and characteristic ultrastructural inclusions should also be screened for CLN8 mutations independent of their ethnic origin.

The neuronal ceroid lipofuscinoses (NCLs) form a group of autosomal recessively inherited neurodegenerative disorders that mainly affect children. Ten NCL forms can be distinguished by age at onset, clinicopathologic features, and genetics. In eight of these forms, the underlying genes have been identified. At present, approximately 10% of all patients do not fall into one of the eight known genetic forms of NCL. We have identified two Asian families with two novel homozygous mutations in the CLN5 gene. In the first Pakistani family, two children developed symptoms of an early juvenile NCL. After exclusion of mutations in genes known to be associated with this age of onset in families from many different countries (CLN1, CLN2, CLN3, CLN6, CLN8 and CLN10) SNP array-based homozygosity mapping led to the identification of a novel homozygous mutation c.1072_1073delTT (p.Leu358AlafsX4) in CLN5. In the second Afghan family, two children developed symptoms of a late infantile NCL. The mutation c.1137G>T (p.Trp379Cys) in CLN5 was identified. The affected children in these families represent the first reported CLN5 patients originating in Asian sibships. Expression analysis showed that mutant p.Leu358AlafsX4 CLN5 is truncated and lacks a used N-glycosylation site at Asn401. The missense mutation p.Trp379Cys affected neither the size nor glycosylation of the CLN5 protein. Double immunofluorescence microscopy showed that while the wild-type CLN5 protein is localized in lysosomes, both mutant CLN5 proteins are retained in the endoplasmic reticulum rather than reaching the lysosome., (Copyright 2009 Wiley-Liss, Inc.)