scholarly journals Variants Associated with Infantile Cholestatic Syndromes Detected in Extrahepatic Biliary Atresia by Whole Exome Studies: A 20-Case Series from Thailand

2018 ◽  
Vol 07 (02) ◽  
pp. 067-073 ◽  
Author(s):  
Wison Laochareonsuk ◽  
Wanwisa Maneechay ◽  
Kanita Kayasut ◽  
Piyawan Chiengkriwate ◽  
Surasak Sangkhathat
Keyword(s):  
Biliary Atresia ◽  
Intrahepatic Cholestasis ◽  
Rare Variants ◽  
Extrahepatic Bile Duct ◽  
Direct Sequencing ◽  
Case Series ◽  
Genetic Syndromes ◽  
Progressive Familial Intrahepatic Cholestasis ◽  
Whole Exome ◽  
Operative Findings

AbstractBiliary atresia (BA) is the most severe form of obstructive cholangiopathy occurring in infants. Definitive diagnosis of BA usually relies on operative findings together with supporting pathological patterns found in the extrahepatic bile duct. In infancy, overlapping clinical patterns of cholestasis can be found in other diseases including biliary hypoplasia and progressive familial intrahepatic cholestasis. In addition, BA has been reported as a phenotype in some rare genetic syndromes. Unlike BA, other cholangiopathic phenotypes have their own established genetic markers. In this study, we used these markers to look for other cholestasis entities in cases diagnosed with BA. DNA from 20 cases of BA, diagnosed by operative findings and histopathology, were subjected to a study of 19 genes associated with infantile cholestasis syndromes, using whole exome sequencing. Variant selection focused on those with allele frequencies in dbSNP150 of less than 0.01. All selected variants were verified by polymerase chain reaction–direct sequencing. Of the 20 cases studied, 13 rare variants were detected in 9 genes: 4 in JAG1 (Alagille syndrome), 2 in MYO5B (progressive familial intrahepatic cholestasis [PFIC] type 6), and one each in ABCC2 (Dubin–Johnson syndrome), ABCB11 (PFIC type 2), UG1A1 (Crigler–Najjar syndrome), MLL2 (Kabuki syndrome), RFX6 (Mitchell–Riley syndrome), ERCC4 (Fanconi anemia), and KCNH1 (Zimmermann–Laband syndrome). Genetic lesions associated with various cholestatic syndromes detected in cases diagnosed with BA raised the hypothesis that severe inflammatory cholangiopathy in BA may not be a distinct disease entity, but a shared pathology among several infantile cholestatic syndromes.

scholarly journals Two Novel Pathogenic Variants of TJP2 Gene and the Underlying Molecular Mechanisms in Progressive Familial Intrahepatic Cholestasis Type 4 Patients

2021 ◽  
Vol 9 ◽  
Author(s):  
Jia Tang ◽  
Meihua Tan ◽  
Yihui Deng ◽  
Hui Tang ◽  
Haihong Shi ◽  
...  
Keyword(s):  
Intrahepatic Cholestasis ◽  
Molecular Mechanisms ◽  
Rare Variants ◽  
Diagnostic Yield ◽  
Underlying Mechanism ◽  
Inherited Disease ◽  
Progressive Familial Intrahepatic Cholestasis ◽  
Pathogenic Variants ◽  
Number Of Patients ◽  
Junction Protein

Progressive familial intrahepatic cholestasis (PFIC) is an autosomal recessive inherited disease that accounts for 10%–15% childhood cholestasis and could lead to infant disability or death. There are three well-established types of PFIC (1–3), caused by mutations in the ATP8B1, ABCB11, and ABCB4 genes. Biallelic pathogenic variants in the tight junction protein 2 gene (TJP2) were newly reported as a cause for PFIC type 4; however, only a limited number of patients and undisputable variants have been reported for TJP2, and the underlying mechanism for PFIC 4 remains poorly understood. To explore the diagnostic yield of TJP2 analysis in suspected PFIC patients negative for the PFIC1–3 mutation, we designed a multiplex polymerase chain reaction-based next-generation sequencing method to analyze TJP2 gene variants in 267 PFIC patients and identified biallelic rare variants in three patients, including three known pathogenic variants and two novel variants in three patients. By using CRISPR-cas9 technology, we demonstrated that TJP2 c.1202A > G was pathogenic at least partially by increasing the expression and nuclear localization of TJP2 protein. With the minigene assay, we showed that TJP2 c.2668-11A > G was a new pathogenic variant by inducing abnormal splicing of TJP2 gene and translation of prematurely truncated TJP2 protein. Furthermore, knockdown of TJP2 protein by siRNA technology led to inhibition of cell proliferation, induction of apoptosis, dispersed F-actin, and disordered microfilaments in LO2 and HepG2celles. Global gene expression profiling of TJP2 knockdown LO2 cells and HepG2 cells identified the dysregulated genes involved in the regulation of actin cytoskeleton. Microtubule cytoskeleton genes were significantly downregulated in TJP2 knockdown cells. The results of this study demonstrate that TJP2 c.1202A > G and TJP2 c.2668-11A > G are two novel pathogenic variants and the cytoskeleton-related functions and pathways might be potential molecular pathogenesis for PFIC.

scholarly journals Clinical outcomes of surgical management for rare types of progressive familial intrahepatic cholestasis: a case series

2022 ◽  
Vol 8 (1) ◽  
Author(s):  
Kazunori Masahata ◽  
Takehisa Ueno ◽  
Kazuhiko Bessho ◽  
Tasuku Kodama ◽  
Ryo Tsukada ◽  
...  
Keyword(s):  
Clinical Outcomes ◽  
Surgical Management ◽  
Intrahepatic Cholestasis ◽  
Case Series ◽  
The Other ◽  
Progressive Familial Intrahepatic Cholestasis ◽  
Donor Liver Transplantation ◽  
Biliary Diversion ◽  
Junction Protein ◽  
Multidrug Resistance Protein 3

Abstract Background Progressive familial intrahepatic cholestasis (PFIC) is a heterogeneous group of genetic autosomal recessive diseases that cause severe cholestasis, which progresses to cirrhosis and liver failure, in infancy or early childhood. We herein report the clinical outcomes of surgical management in patients with four types of PFIC. Case presentation Six patients diagnosed with PFIC who underwent surgical treatment between 1998 and 2020 at our institution were retrospectively assessed. Living-donor liver transplantation (LDLT) was performed in 5 patients with PFIC. The median age at LDLT was 4.8 (range: 1.9–11.4) years. One patient each with familial intrahepatic cholestasis 1 (FIC1) deficiency and bile salt export pump (BSEP) deficiency died after LDLT, and the four remaining patients, one each with deficiency of FIC1, BSEP, multidrug resistance protein 3 (MDR3), and tight junction protein 2 (TJP2), survived. One FIC1 deficiency recipient underwent LDLT secondary to deterioration of liver function, following infectious enteritis. Although he underwent LDLT accompanied by total external biliary diversion, the patient died because of PFIC-related complications. The other patient with FIC1 deficiency had intractable pruritus and underwent partial internal biliary diversion (PIBD) at 9.8 years of age, pruritus largely resolved after PIBD. One BSEP deficiency recipient, who had severe graft damage, experienced recurrence of cholestasis due to the development of antibodies against BSEP after LDLT, and eventually died due to graft failure. The other patient with BSEP deficiency recovered well after LDLT and there was no evidence of posttransplant recurrence of cholestasis. In contrast, recipients with MDR3 or TJP2 deficiency showed good courses and outcomes after LDLT. Conclusions Although LDLT was considered an effective treatment for PFIC, the clinical courses and outcomes after LDLT were still inadequate in patients with FIC1 and BSEP deficiency. LDLT accompanied by total biliary diversion may not be as effective for patients with FIC1 deficiency.

A novel etiologic factor of highly elevated cholestanol levels: progressive familial intrahepatic cholestasis

2020 ◽  
Vol 33 (5) ◽  
pp. 665-669
Author(s):  
Aynur Küçükçongar Yavaş ◽  
Büşra Çavdarlı ◽  
Özlem Ünal Uzun ◽  
Ayşen Uncuoğlu ◽  
Mehmet Gündüz
Keyword(s):  
Primary Biliary Cirrhosis ◽  
Intrahepatic Cholestasis ◽  
Density Lipoprotein ◽  
Etiologic Factor ◽  
Compound Heterozygous ◽  
Cholestatic Liver Disease ◽  
Biliary Cirrhosis ◽  
Progressive Familial Intrahepatic Cholestasis ◽  
Turkish Patient ◽  
Type 3

AbstractBackgroundProgressive familial intrahepatic cholestasis type 3 (PFIC3) is an uncommon cholestatic liver disease caused by mutations in the ATP binding cassette subfamily B member 4 (ABCB4) gene. Although PFIC3 is frequently identified in childhood, ABCB4 disease-causing alleles have been described in adults affected by intrahepatic cholestasis of pregnancy, hormone-induced cholestasis, low-phospholipid-associated cholelithiasis syndrome or juvenile cholelithiasis, cholangiocarcinoma and in sporadic forms of primary biliary cirrhosis. Cholestanol is a biomarker which is elevated especially in cerebrotendinous xanthomatosis and rarely in primary biliary cirrhosis (PBC) and Niemann Pick type C.Case presentationHere we report a Turkish patient with compound heterozygous mutations in the ABCB4 gene, who has hepatosplenomegaly, low level of high-density lipoprotein, cholestasis and high level of cholestanol.ConclusionThis is the first PFIC3 case with a high cholestanol level described in the literature. There are very few diseases linked to increased cholestanol levels, two of which are CTX and PBC. From this case, we can conclude that a high cholestanol level might be another indicator of PFIC type 3.

scholarly journals Hunting for Familial Parkinson’s Disease Mutations in the Post Genome Era

Genes ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 430
Author(s):  
Steven R. Bentley ◽  
Ilaria Guella ◽  
Holly E. Sherman ◽  
Hannah M. Neuendorf ◽  
Alex M. Sykes ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Family History ◽  
Rare Variants ◽  
Strong Family History ◽  
Disease Mutations ◽  
Whole Exome ◽  
History Of ◽  
Functional Consequences ◽  
Multiplex Families

Parkinson’s disease (PD) is typically sporadic; however, multi-incident families provide a powerful platform to discover novel genetic forms of disease. Their identification supports deciphering molecular processes leading to disease and may inform of new therapeutic targets. The LRRK2 p.G2019S mutation causes PD in 42.5–68% of carriers by the age of 80 years. We hypothesise similarly intermediately penetrant mutations may present in multi-incident families with a generally strong family history of disease. We have analysed six multiplex families for missense variants using whole exome sequencing to find 32 rare heterozygous mutations shared amongst affected members. Included in these mutations was the KCNJ15 p.R28C variant, identified in five affected members of the same family, two elderly unaffected members of the same family, and two unrelated PD cases. Additionally, the SIPA1L1 p.R236Q variant was identified in three related affected members and an unrelated familial case. While the evidence presented here is not sufficient to assign causality to these rare variants, it does provide novel candidates for hypothesis testing in other modestly sized families with a strong family history. Future analysis will include characterisation of functional consequences and assessment of carriers in other familial cases.

scholarly journals Exome sequencing in paediatric patients with movement disorders

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Anna Ka-Yee Kwong ◽  
Mandy Ho-Yin Tsang ◽  
Jasmine Lee-Fong Fung ◽  
Christopher Chun-Yu Mak ◽  
Kate Lok-San Chan ◽  
...  
Keyword(s):  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Movement Disorders ◽  
Rare Variants ◽  
Diagnostic Yield ◽  
Neurological Diseases ◽  
Genetic Diagnosis ◽  
Potential Treatment ◽  
Paediatric Patients ◽  
Whole Exome

Abstract Background Movement disorders are a group of heterogeneous neurological diseases including hyperkinetic disorders with unwanted excess movements and hypokinetic disorders with reduction in the degree of movements. The objective of our study is to investigate the genetic etiology of a cohort of paediatric patients with movement disorders by whole exome sequencing and to review the potential treatment implications after a genetic diagnosis. Results We studied a cohort of 31 patients who have paediatric-onset movement disorders with unrevealing etiologies. Whole exome sequencing was performed and rare variants were interrogated for pathogenicity. Genetic diagnoses have been confirmed in 10 patients with disease-causing variants in CTNNB1, SPAST, ATP1A3, PURA, SLC2A1, KMT2B, ACTB, GNAO1 and SPG11. 80% (8/10) of patients with genetic diagnosis have potential treatment implications and treatments have been offered to them. One patient with KMT2B dystonia showed clinical improvement with decrease in dystonia after receiving globus pallidus interna deep brain stimulation. Conclusions A diagnostic yield of 32% (10/31) was reported in our cohort and this allows a better prediction of prognosis and contributes to a more effective clinical management. The study highlights the potential of implementing precision medicine in the patients.

scholarly journals A Novel Compound Heterozygous Mutation in ABCB4 Gene Leading to Cholelithiasis, Progressive Familial Intrahepatic Cholestasis (Type 3), and Cirrhosis in a Child

2020 ◽  
Vol 10 (01) ◽  
pp. e134-e136
Author(s):  
Nida Mirza ◽  
Smita Malhotra ◽  
Anupam Sibal
Keyword(s):  
Intrahepatic Cholestasis ◽  
Gall Stone ◽  
Compound Heterozygous Mutation ◽  
Heterozygous Mutation ◽  
Compound Heterozygous ◽  
Initial Symptom ◽  
Progressive Familial Intrahepatic Cholestasis ◽  
Presenting Symptoms ◽  
Abcb4 Gene ◽  
Type 3

AbstractProgressive familial intrahepatic cholestasis (PFIC) is a heterogeneous group of autosomal recessive disorders of childhood which presents with intermittent or progressive episodes of cholestasis, with jaundice and pruritus as most common presenting symptoms. PFIC type 3 occurs due to mutations in the ABCB4 gene, mutation in this gene has wide spectrum of features which include intrahepatic stones, cholelithiasis, PFIC type 3, and intrahepatic cholestasis of pregnancy. Here, we are reporting a peculiar case of young male adolescent with novel variant compound heterozygote missense mutation in ABCB4 gene who had gall stone as initial symptom, followed by symptoms of PFIC and eventually decompensated chronic liver disease.

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