1.Study of a case of Juvenile neuronal ceroid lipofuscinosis due to compound heterozygous variants of PPT1 gene.
Dan ZHANG ; Fang XU ; Yi BAO ; Yanming XU
Chinese Journal of Medical Genetics 2024;41(12):1469-1472
OBJECTIVE:
To report and analyze a case of Juvenile neuronal ceroid lipofuscinosis (NCL) due to compound heterozygous variants of PPT1 gene.
METHODS:
A child who was admitted to the Department of Neurology of West China Hospital of Sichuan University in April 2021 due to "intellectual decline and behavioral abnormalities for more than 5 years and movement disorder for more than 1 year" was selected as the study subject. Clinical data of the child was collected. Trio-whole exome sequencing was carried out for the child and his parents, and clinical follow-up was conducted. This study has been approved by the Medical Ethics Committee of West China Hospital of Sichuan University (Ethic No. 2024-2286).
RESULTS:
The patient, a 13-year-old male, showed progressive mental decline, behavioral abnormalities, and movement disorders from the age of 8. Electroencephalogram showed abnormal background activities, and magnetic resonance imaging showed brain atrophy. Trio-whole exome sequencing revealed that he had harbored a paternally derived heterozygous c.272(exon3)A>C variant and a maternally derived heterozygous c.176(exon2)A>G variant of the PPT1 gene. His presentation was in keeping with previously reported juvenile NCL due to variants of the PPT1 gene.
CONCLUSION
The c.272(exon3)A>C and c.176(exon2)A>G compound heterozygous variants of the PPT1 gene probably underlay the Juvenile NCL in this child. Discovery of the c.176(exon2)A>G variant has expanded the mutational spectrum of this disease.
Humans
;
Neuronal Ceroid-Lipofuscinoses/genetics*
;
Male
;
Adolescent
;
Heterozygote
;
Thiolester Hydrolases/genetics*
;
Membrane Proteins/genetics*
;
Exome Sequencing
;
Mutation
2.Clinical characteristics and genetic analysis of a case with adult neuronal ceroid lipofuscinosis type 7 due to variant of MFSD8 gene.
Shuang HE ; Shuai CHEN ; Yue PENG ; Xiaorui FAN ; Shujian LI ; Jiewen ZHANG
Chinese Journal of Medical Genetics 2023;40(4):395-401
OBJECTIVE:
To explore the clinical characteristics and genetic variants in a patient with adult ceroid lipofuscinosis neuronal type 7 (ACLN7).
METHODS:
A female patient diagnosed with ACLN7 in Henan Provincial People's Hospital in June 2021 was selected as the study subject. Clinical data, auxiliary examination and result of genetic testing were retrospectively analyzed.
RESULTS:
The patient, a 39-year-old female, has mainly presented progressive visual loss, epilepsy, cerebellar ataxia and mild cognitive decline. Neuroimaging analysis has revealed generalized brain atrophy, prominently cerebellum. Fundus photography has revealed retinitis pigmentosa. Ultrastructural skin examination has revealed granular lipofuscin deposits in the periglandular interstitial cells. Whole exome sequencing revealed that she has harbored compound heterozygous variants of the MSFD8 gene, namely c.1444C>T (p.R482*) and c.104G>A (p.R35Q). Among these, c.1444C>T (p.R482*) was a well established pathogenic variant, while c.104G>A (p.R35Q) was a missense variant unreported previously. Sanger sequencing confirmed that the daughter, son and elder brother of the proband have respectively carried heterozygous c.1444C>T (p.R482*), c.104G>A (p.R35Q), and c.104G>A (p.R35Q) variants of the same gene. The family has therefore fit with the autosomal recessive inheritance pattern of the CLN7.
CONCLUSION
Compared with previously reported cases, this patient has the latest onset of the disease with a non-lethal phenotype. Her clinical features have involved multiple systems. Cerebellar atrophy and fundus photography may be indicative of the diagnosis. The c.1444C>T (p.R482*) and c.104G>A (p.R35Q) compound heterozygous variants of the MFSD8 gene probably underlay the pathogenesis in this patient.
Male
;
Female
;
Humans
;
Membrane Transport Proteins/genetics*
;
Neuronal Ceroid-Lipofuscinoses/diagnosis*
;
Retrospective Studies
;
Atrophy
;
Mutation
4.Genetic and clinical analysis of a novel GLB1 gene variant in a Chinese patient with GM1-gangliosidosis.
Shuangxi CHENG ; Qingming WANG ; Aixin CHEN ; Lingfang ZHOU ; Xiaochun HONG ; Haiming YUAN
Chinese Journal of Medical Genetics 2022;39(5):537-541
OBJECTIVE:
To explore the genotype-phenotype correlation of a case with GM1-gangliosidosis caused by compound heterogenic variants in GLB1.
METHODS:
Genomic DNA was extracted from peripheral blood samples from the patient and her parents. Trio-based whole-exome sequencing (WES) was performed for the family and suspected mutation was verified by Sanger sequencing.
RESULTS:
The proband, a 2-year-3-month old Chinese girl, presented with psychomotor deterioration, absent speech, intellectual disabilities and behavior problem. Trio-based WES has identified compound heterozygosity for 2 variants in the GLB1 gene: NM_000404.2:c.1343A>T, p.Asp448Val and c.1064A>C, p.Gln355Pro (GRCh37/hg19),which was inherited from the mother and father, respectively. Homozygous or compound heterozygous pathogenic variants in GLB1, encoding β-galactosidase, are responsible for GM1-gangliosidosis,an autosomal recessive lysosomal storage disorder characterized by variable degrees of neurodegeneration and skeletal abnormalities. The p.Asp448Val variant has been classified as pathogenic for GM1 gangliosidosis in medical literatures for the reason that functional studies demonstrated that expression of the p.Asp448Val variant in COS-1 cells resulted in no detectable β-galactosidase activity compared to wild type GLB1. The p.Gln355Pro variant has not been reported in literatures or database. The variant is highly conserved residue (PM1), and was not found in either the Genome Aggregation Database or the 1000 Genomes Project (PM2) and was predicted to have a deleterious effect on the gene product by multiple in silico prediction tools (PP3). Next, the β-galactosidase activity of the patient's peripheral blood leukocytes was determined by fluorescent method. The result was 0.0 nmol/mg. It showed that the p.Gln355Pro variant also resulted in loss of β-galactosidase activity, thus the variant was classified into clinical pathogenic variant.
CONCLUSION
Our study expands the mutational spectrum of the GLB1 gene and provides genetic counseling for the family.
Asians/genetics*
;
China
;
Female
;
G(M1) Ganglioside
;
Gangliosidosis, GM1/genetics*
;
Humans
;
Mutation
;
beta-Galactosidase/genetics*
5.Clinicopathological study of Gaucher disease.
Yan Xia WANG ; Mei Chen WEI ; Shou Jing YANG
Chinese Journal of Pathology 2022;51(11):1158-1160
7.ROS Scavenger, Ebselen, Has No Preventive Effect in New Hearing Loss Model Using a Cholesterol-Chelating Agent
Min Young LEE ; Lisa L KABARA ; Donald L SWIDERSKI ; Yehoash RAPHAEL ; R Keith DUNCAN ; Young Ho KIM
Journal of Audiology & Otology 2019;23(2):69-75
BACKGROUND AND OBJECTIVES: The antioxidant ebselen will be able to limit or prevent the ototoxicity arising from 2-hydroxypropyl-β-cyclodextrin (HPβCD). Niemann-Pick Type C (NPC) disease is a disorder of lysosomal storage manifested in sphingolipidosis. Recently, it was noted that experimental use of HPβCD could partially resolve the symptoms in both animals and human patients. Despite its desirable effect, HPβCD can induce hearing loss, which is the only major side effect noted to date. Understanding of the pathophysiology of hearing impairment after administration of HPβCD and further development of preventive methods are essential to reduce the ototoxic side effect. The mechanisms of HPβCD-induced ototoxicity remain unknown, but the resulting pathology bears some resemblance to other ototoxic agents, which involves oxidative stress pathways. To indirectly determine the involvement of oxidative stress in HPβCD-induced ototoxicity, we tested the efficacy of an antioxidant reagent, ebselen, on the extent of inner ear side effects caused by HPβCD. MATERIALS AND METHODS: Ebselen was applied prior to administration of HPβCD in mice. Auditory brainstem response thresholds and otopathology were assessed one week later. Bilateral effects of the drug treatments also were examined. RESULTS: HPβCD-alone resulted in bilateral, severe, and selective loss of outer hair cells from base to apex with an abrupt transition between lesions and intact areas. Ebselen co-treatment did not ameliorate HPβCD-induced hearing loss or alter the resulting histopathology. CONCLUSIONS: The results indirectly suggest that cochlear damage by HPβCD is unrelated to reactive oxygen species formation. However, further research into the mechanism(s) of HPβCD otopathology is necessary.
Animals
;
Ear, Inner
;
Evoked Potentials, Auditory, Brain Stem
;
Hair Cells, Auditory, Outer
;
Hearing Loss
;
Hearing
;
Humans
;
Mice
;
Oxidative Stress
;
Pathology
;
Reactive Oxygen Species
;
Sphingolipidoses
;
Tight Junctions
8.Genetic study of a family of neuronal ceroid lipofuscinosis caused by a heterozygous mutation of gene.
Tie LOU ; Yingzhi HUANG ; Minyue DONG
Journal of Zhejiang University. Medical sciences 2019;48(4):373-377
OBJECTIVE:
To analyze the genetic cause of a family with autosomal recessive neuronal ceroid lipofuscinoses (NCL).
METHODS:
The proband was screened for mutations within the coding region of the candidate genes through high-throughput targeted sequencing. Potential causative mutations were verified by PCR and Sanger sequencing in the proband and his parents. RT-PCR and TA clone sequencing were performed to investigate whether the mRNAs were abnormally spliced.
RESULTS:
The sequencing results revealed compound heterozygous mutations of :c.486+2T>C and c.486+4A>T, which were respectively inherited from his parents. RT-PCR and TA cloning sequencing suggested that the mRNAs were abnormally spliced in two forms due to both mutations.
CONCLUSIONS
The compound heterozygous mutations of :c.486+2T>C and c.486+4A>T are possibly the genetic causes of the NCL family. Detection of the novel mutation has extended mutation spectrum of .
Alternative Splicing
;
Female
;
Humans
;
Male
;
Membrane Proteins
;
genetics
;
Mutation
;
Neuronal Ceroid-Lipofuscinoses
;
genetics
9.Identification and pathogenicity prediction of a novel GLB1 variant c.101T>C (p.Ile34Thr) in an infant with GM1 gangliosidosis.
Xue-Rong LAN ; Jian-Wu QIU ; Hua LI ; Xiang-Ran CAI ; Yuan-Zong SONG
Chinese Journal of Contemporary Pediatrics 2019;21(1):71-76
GM1 gangliosidosis is an autosomal recessive disorder caused by galactosidase beta1 (GLB1) gene variants which affect the activity of β-galactosidase (GLB). GLB dysfunction causes abnormalities in the degradation of GM1 and its accumulation in lysosome. This article reports the clinical and genetic features of a child with GM1 gangliosidosis. The girl, aged 2 years and 5 months, was referred to the hospital due to motor developmental regression for more than one year. Physical examination showed binocular deflection and horizontal nystagmus, but no abnormality was found on fundoscopy. The girl had increased muscular tone of the extremities, limitation of motion of the elbow, knee, and ankle joints, and hyperactive patellar tendon reflex. Blood biochemical examination showed a significant increase in aspartate aminotransferase. The 24-hour electroencephalographic monitoring detected frequent seizure attacks and diffuse θ wave activity, especially in the right hemisphere. Head magnetic resonance imaging showed thinner white matter in the periventricular region and diffuse high T2WI signal with unclear boundary. Three-dimensional reconstruction of white matter fiber tracts by diffusion tensor imaging showed smaller and thinner white matter fiber tracts, especially in the right hemisphere. Genetic analysis showed that the girl had compound heterozygous mutations of c.446C>T (p.Ser149Phe) and c.101T>C (p.Ile34Thr) in the GLB1 gene from her parents, among which c.101T>C (p.Ile34Thr) had not been reported in the literatures. The girl was finally diagnosed with GM1 gangliosidosis. Her conditions were not improved after antiepileptic treatment and rehabilitation training for 2 months.
Diffusion Tensor Imaging
;
Female
;
Gangliosidosis, GM1
;
genetics
;
Humans
;
Infant
;
Mutation
;
Virulence
;
beta-Galactosidase
;
genetics
10.Novel mutations of GLB1 gene identified in a Chinese pedigree affected with GM1 gangliosidosis.
Min GAO ; Ruifeng JIN ; Kaihui ZHANG ; Zhiyi LI ; Zhongtao GAI ; Yi LIU
Chinese Journal of Medical Genetics 2019;36(2):128-131
OBJECTIVE:
To explore the genetic cause for a child with growth retardation by next generation sequencing (NGS).
METHODS:
Clinical data of the patient was collected. Peripheral venous blood samples were taken from the neonate and his parents. Targeted capturing and NGS were carried out to detect mutations of genes associated with inborn errors of metabolism. Suspected mutations were validated by Sanger sequencing.
RESULTS:
The 15-month-old female patient was admitted to hospital for growth retardation for 4 months. Hypomyelination was found upon cranium MRI. Genetic testing revealed two novel insertional mutations in the GLB1 gene in the patient, namely c.2006-2007insT and c.475-476 insGGTCC.
CONCLUSION
The c.2006-2007insT and c.475-476 insGGTCC mutations of the GLB1 gene probably underlie the GM1 gangliosidosis resulting in the growth retardation in the child.
Female
;
Gangliosidosis, GM1
;
genetics
;
Humans
;
Infant
;
Infant, Newborn
;
Mutation
;
Pedigree
;
beta-Galactosidase
;
genetics

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