scholarly journals Using whole‐exome sequencing to investigate the genetic bases of lysosomal storage diseases of unknown etiology

2017 ◽  
Vol 38 (11) ◽  
pp. 1491-1499 ◽  
Author(s):  
Nan Wang ◽  
Yeting Zhang ◽  
Erika Gedvilaite ◽  
Jui Wan Loh ◽  
Timothy Lin ◽  
...  
Nephron ◽  
2021 ◽  
pp. 1-6
Author(s):  
Suramath Isaranuwatchai ◽  
Ankanee Chanakul ◽  
Chupong Ittiwut ◽  
Chalurmpon Srichomthong ◽  
Vorasuk Shotelersuk ◽  
...  

Chronic kidney disease of unknown etiology (CKDu) has been a problem in renal practice as indefinite diagnosis may lead to inappropriate management. Here, we report a 54-year-old father diagnosed with CKDu at 33 years old and his 8-year-old son with steroid-resistant nephrotic syndrome. Using whole-exome sequencing, both were found to be heterozygous for c.737G>A (p.Arg246Gln) in LMX1B. The diagnosis of LMX1B-associated nephropathy has led to changes in the treatment plan with appropriate genetic counseling. The previously reported cases with this particular mutation were also reviewed. Most children with LMX1B-associated nephropathy had nonnephrotic proteinuria with normal renal function. Interestingly, our pediatric case presented with steroid-resistant nephrotic syndrome at 8 years old and progressed to ESRD requiring peritoneal dialysis at the age of 15 years. Our report emphasized the need of genetic testing in CKDu for definite diagnosis leading to precise management.


Author(s):  
Qingwen Zeng ◽  
Yanjie Fan ◽  
Lili Wang ◽  
Zhuo Huang ◽  
Xuefan Gu ◽  
...  

AbstractBackground:Mucopolysaccharidosis IIIB (MPS IIIB) is a genetic disease characterized by mutations in theCase presentation:Whole exome sequencing (WES) was conducted and the putative pathogenic variants were validated by Sanger sequencing. The activity of MPS IIIB related enzyme in the patient’s blood serum was assayed. A heterozygous, non-synonymous mutation (c.1562C>T, p.P521L) as well as a novel mutation (c.1705C>A, p.Q569K) were found in theConclusions:Our results describe an atypical form of MPS IIIB and illustrate the diagnostic potential of targeted WES in Mendelian disease with unknown etiology. WES could become a powerful tool for molecular diagnosis of MPS IIIB in clinical setting.


2020 ◽  
Vol 4 (12) ◽  
Author(s):  
Stephen I Stone ◽  
Daniel J Wegner ◽  
Jennifer A Wambach ◽  
F Sessions Cole ◽  
Fumihiko Urano ◽  
...  

Abstract Insulin-mediated pseudoacromegaly (IMPA) is a rare disease of unknown etiology. Here we report a 12-year-old female with acanthosis nigricans, hirsutism, and acromegalic features characteristic of IMPA. The subject was noted to have normal growth hormone secretion, with extremely elevated insulin levels. Studies were undertaken to determine a potential genetic etiology for IMPA. The proband and her family members underwent whole exome sequencing. Functional studies were undertaken to validate the pathogenicity of candidate variant alleles. Whole exome sequencing identified monoallelic, predicted deleterious variants in genes that mediate fibroblast growth factor 21 (FGF21) signaling, FGFR1 and KLB, which were inherited in trans from each parent. FGF21 has multiple metabolic functions but no known role in human insulin resistance syndromes. Analysis of the function of the FGFR1 and KLB variants in vitro showed greatly attenuated ERK phosphorylation in response to FGF21, but not FGF2, suggesting that these variants act synergistically to inhibit endocrine FGF21 signaling but not canonical FGF2 signaling. Therefore, digenic variants in FGFR1 and KLB provide a potential explanation for the subject’s severe insulin resistance and may represent a novel category of insulin resistance syndromes related to FGF21.


2018 ◽  
Author(s):  
Huijuan Zhu ◽  
Ziying Yang ◽  
Jun Sun ◽  
Wei Li ◽  
Hongbo Yang ◽  
...  

AbstractShort stature is among the most common reasons for children being referred to the pediatric endocrinology clinics. The cause of short stature is broad, in which genetic factors play a substantial role, especially in primary growth disorders. However, identifying the molecular causes for short stature remains as a challenge because of the high heterogeneity of the phenotypes. Here, whole exome sequencing (WES) was used to identify the genetic causes of short stature with unknown etiology for 20 patients aged from 1 to 16 years old. The genetic causes of short stature were identified in 9 of the 20 patients, corresponding to a molecular diagnostic rate of 45%. Notably, in 2 of the 9 patients identified with genetic causes, the diagnosed diseases based on WES are different from the original clinical diagnosis. Our results highlight the clinical utility of WES in the diagnosis of rare, high heterogeneity disorders.


Author(s):  
Muhsin Elmas ◽  
Basak Gogus ◽  
Furkan Kılıçarslan ◽  
Aysegul Bukulmez ◽  
Mustafa Solak

AbstractMucopolysaccharidosis type IIIB (Sanfilippo's B; OMIM no.: 252920) is a lysosomal storage disorder caused by defective degradation of heparan sulfate. The enzyme that has decreased function in this disease is α-N acetylglucosaminidase. This enzyme is encoded by the NAGLU gene. A 9-year-old male patient was referred to us with speech disability, developmental delay, hepatomegaly, mild learning disability, and otitis media with effusion complaints. Whole exome sequencing (WES) was performed because of consanguinity between the parents of the patient and the lack of specific prediagnosis. As a result of the patient's WES analysis, a homozygous mutation was detected in the NAGLU gene. The leukocyte enzyme activity was then evaluated to confirm the diagnosis. Alpha-N acetylglucosaminidase deficiency was found. Alpha-N acetylglucosaminidase activity was 0.2 nmol/mLh. WES is a successful diagnostic method in the diagnosis of the mild clinical diseases with recessive inheritance. In addition, our case is a good example of genotype to phenotype diagnosis. Because in storage diseases, the diagnosis is made by leukocyte enzyme analysis first, and then the result is confirmed by gene analysis. The opposite situation occurred in our case.


2009 ◽  
Vol 8 (7) ◽  
pp. 1708-1718 ◽  
Author(s):  
David E. Sleat ◽  
Lin Ding ◽  
Shudan Wang ◽  
Caifeng Zhao ◽  
Yanhong Wang ◽  
...  

Author(s):  
Carole Vogler ◽  
Harvey S. Rosenberg

Diagnostic procedures for evaluation of patients with lysosomal storage diseases (LSD) seek to identify a deficiency of a responsible lysosomal enzyme or accumulation of a substance that requires the missing enzyme for degradation. Most patients with LSD have progressive neurological degeneration and may have a variety of musculoskeletal and visceral abnormalities. In the LSD, the abnormally diminished lysosomal enzyme results in accumulation of unmetabolized catabolites in distended lysosomes. Because of the subcellular morphology and size of lysosomes, electron microscopy is an ideal tool to study tissue from patients with suspected LSD. In patients with LSD all cells lack the specific lysosomal enzyme but the distribution of storage material is dependent on the extent of catabolism of the substrate in each cell type under normal circumstances. Lysosmal storages diseases affect many cell types and tissues. Storage material though does not accumulate in all tissues and cell types and may be different biochemically and morphologically in different tissues.Conjunctiva, skin, rectal mucosa and peripheral blood leukocytes may show ultrastructural evidence of lysosomal storage even in the absence of clinical findings and thus any of these tissues can be used for ultrastructural examination in the diagnostic evaluation of patients with suspected LSD. Biopsy of skin and conjunctiva are easily obtained and provide multiple cell types including endothelium, epithelium, fibroblasts and nerves for ultrastructural study. Fibroblasts from skin and conjunctiva can also be utilized for the initiation of tissue cultures for chemical assays. Brain biopsy has been largely replaced by biopsy of more readily obtained tissue and by biochemical assays. Such assays though may give equivical or nondiagnostic results and in some lysosomal storage diseases an enzyme defect has not yet been identified and diagnoses can be made only by ultrastructural examination.


2014 ◽  
Vol 62 (S 02) ◽  
Author(s):  
M. Hitz ◽  
S. Al-Turki ◽  
A. Schalinski ◽  
U. Bauer ◽  
T. Pickardt ◽  
...  

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