Targeting cholesterol trafficking to mitigate axonal degeneration in hereditary spastic paraplegia

Axonal degeneration underlies many debilitating diseases including hereditary spastic paraplegia(HSP),a genetically and clinically diverse group of disorders characterized by spasticity and weakness of the lower extremities.HSP is one significant cause of chronic neurodisability due to the lack of effective treatments and a wide range of onset ages from early childhood to 70 years.

Dual primary gastric and colorectal cancer:The known hereditary causes and underlying mechanisms

In this editorial,I commented on the paper by Lin et al,published in this issue of the World Journal of Gastrointestinal Oncology.The work aimed at analysing the clinicopathologic characteristics and prognosis of synchronous and metachronous cancers in patients with dual primary gastric and colorectal cancer(CRC).The authors concluded the necessity for regular surveillance for metachronous cancer during postoperative follow-up and reported the prognosis is influenced by the gastric cancer(GC)stage rather than the CRC stage.Although surveillance was recommended in the conclusion,the authors did not explore this area in their study and did not include tests used for such surveillance.This editorial focuses on the most characterized gastrointestinal cancer susceptibility syndromes concerning dual gastric and CRCs.These include hereditary diffuse GC,familial adenomatous polyposis,hereditary nonpolyposis colon cancer,Lynch syndrome,and three major hamartomatous polyposis syndromes associated with CRC and GC,namely Peutz-Jeghers syndrome,juvenile polyposis syndrome,and PTEN hamartoma syndrome.Careful assessment of these syndromes/conditions,including inheritance,risk of gastric and colorectal or other cancer development,genetic mutations and recommended genetic investigations,is crucial for optimum management of these patients.

Genetically modified pigs:Emerging animal models for hereditary hearing loss

Hereditary hearing loss(HHL),a genetic disorder that impairs auditory function,significantly affects quality of life and incurs substantial economic losses for society.To investigate the underlying causes of HHL and evaluate therapeutic outcomes,appropriate animal models are necessary.Pigs have been extensively used as valuable large animal models in biomedical research.In this review,we highlight the advantages of pig models in terms of ear anatomy,inner ear morphology,and electrophysiological characteristics,as well as recent advancements in the development of distinct genetically modified porcine models of hearing loss.Additionally,we discuss the prospects,challenges,and recommendations regarding the use pig models in HHL research.Overall,this review provides insights and perspectives for future studies on HHL using porcine models.

Complex heterozygous mutations in hereditary spherocytosis:A case report

BACKGROUND The aim of this study was to investigate the complex heterozygous mutations of ANK1 and SPTA1 in the same individual and improve our understanding of hereditary spherocytosis(HS)in children.We also hope to promote the application of gene detection technology in children with HS,with the goals of identifying more related gene mutations,supporting the acquisition of improved molecular genetic information to further reveal the pathogenesis of HS in children,and providing important guidance for the diagnosis,treatment,and prevention of HS in children.CASE SUMMARY A 1-year and 5-month-old patient presented jaundice during the neonatal period,mild anemia 8 months later,splenic enlargement at 1 year and 5 months,and brittle red blood cell permeability.Genetic testing was performed on the patient,their parents,and sister.Swiss Model software was used to predict the protein structure of complex heterozygous mutations in ANK1 and SPTA1.Genetic testing revealed that the patient harbored a new mutation in the ANK1 gene from the father and a mutation in the SPTA1 gene from the mother.Combined with the clinical symptoms of the children,it is suggested that the newly discovered complex heterozygous mutations of ANK1 and SPTA1 may be the cause,providing important guidance for revealing the pathogenesis,diagnosis,treatment,and promotion of gene detection technology in children with HS.CONCLUSION This case involves an unreported complex heterozygous mutation of ANK1 and SPTA1,which provides a reference for exploring HS.

Germline pathogenic variants among high hereditary risk patients with breast and ovarian cancer and unaffected subjects in Lebanese Arab women

BACKGROUND The prevalence of germline pathogenic variants in high hereditary risk breast and/or ovarian cancer patients and unaffected subjects referred for testing is an unmet need in low and middle-income countries.AIM To determine the prevalence of germline pathogenic variants in high hereditary risk patients with breast and/or ovarian cancer and unaffected individuals.METHODS We retrospectively reviewed records of patients and unaffected subjects referred for germline pathogenic variant testing due to high hereditary risk between 2010-2020.Data was collected and analyzed on Excel sheet.RESULTS In total,358 individuals were included,including 257 patients and 101 unaffected individuals with relatives with breast or ovarian cancer.The prevalence of breast cancer susceptibility gene(BRCA)1/2 pathogenic variants was 8.63%(19/220)in patients with breast cancer,and 15.1%(5/33)in those with ovarian cancer.Among the 25 of 220 patients with breast cancer tested by next-generation sequencing,3 patients had pathogenic variants other than BRCA1/2.The highest risk was observed in those aged 40 years with breast cancer and a positive family history,where the BRCA1/2 prevalence was 20.1%(9/43).Among the unaffected subjects,31.1%(14/45)had the same BRCA1/2 pathogenic variants in their corresponding relatives.Among the subjects referred because of a positive family history of cancer without known hereditary factors,5.35%(3/56)had pathogenic variants of BRCA1 and BRCA2.The c.131G>T nucleotide change was noted in one patient and two unrelated unaffected subjects with a BRCA1 pathogenic variant.CONCLUSION This study showed a 8.63%prevalence of pathogenic variants in patients with breast cancer and a 15.1%prevalence in patients with ovarian cancer.Among the relatives of patients with BRCA1/2 pathogenic variants,31%tested positive for the same variant,while 5.3%of subjects who tested positive due to a family history of breast cancer had a BRCA pathogenic variant.

Analysis of Hereditary Stability and Disease Susceptivity of sFat-1 Transgenic Pigs

[Objective] This study aimed to investigate the hereditary stability of sFat-1 transgenic pigs and the differences in disease susceptivity between sFat-1 transgenic pigs and non-transgenic pigs. [Method] The integration of sFat-1 gene in pigs was detected by PCR; the infection of transgenic pig to pseudorabies, leptospirosis, swine dysentery, brucellosis, Mycobacterium tuberculosis, rotavirus and mycoplasma hyopneumoniae was detected by using ELISA and PCR. [Result] The positive ratio of F3 generation sFat-1 transgenic pigs was 18.5%; the susceptivity of positive sFat- 1 transgenic and negative pigs to seven infectious diseases showed no significant difference. [Conclusion] Exogenous gene in sFat-1 transgenic pigs can not be stably inherited. The overall physical condition of positive transgenic and negative pigs was similar.

Hereditary non-polyposis colorectal cancer: The rise and fall of a confusing term

The term Hereditary Non-Polyposis Colorectal Cancer （HNPCC） is a poor descriptor of the syndrome described by Lynch. Over the last decade, the term has been applied to heterogeneous groups of families meeting limited clinical criteria, for example the Amsterdam criteria. It is now apparent that not all Amsterdam criteria-positive families have the Lynch syndrome. The term HNPCC has also been applied to clinical scenarios in which CRCs with DNA microsateUite instability are diagnosed but in which there is no vertical transmission of an altered DNA mismatch repair （MMR） gene. A term that has multiple, mutually incompatible meanings is highly problematic, particularly when it may influence the management of an individual family. The Lynch syndrome is best understood as a hereditary predisposition to malignancy that is explained by a germline mutation in a DNA MMR gene. The diagnosis does not depend in an absolute sense on any particular family pedigree structure or age of onset of malignancy. Families with a strong family history of colorectal cancer that do not have Lynch syndrome have been grouped as ‘Familial Colorectal Cancer Type-X＇. The first step in characterizing these cancer families is to distinguish them from Lynch syndrome. The term HNPCC no longer serves any useful purpose and should be phased out.

Primary shunt hyperbilirubinaemia in a large four-generation family confirming autosomai dominant genetic disorder

AIM： To describe the pattern of inheritance and confirm the diagnostic criteda of primary shunt hyperbilirubinaemia （PSH）. METHODS： Forty members of a family pedigree across four generations were included in this study. All family members were interviewed and investigated by physical examination, hematology and liver function test and the pattern of inheritance was analyzed. RESULTS： Nine of the forty family members suffered primary shunt hyperbilirubinaemia. The mature erythrocytes of the propositus were irregular in shape and size. The pedigree showed transmission of the trait through four generations with equal distribution in male and female. No individual with a primary shunt hyperbilirubinaemia was born to unaffected parents. The penetrance was complete in adult. CONCLUSION： The pattern of inheritance is autosomal dominant. The abnormality of erythrocytes and decrease in white blood cell could be supplemented in the diagnosis of PSH. The PSH is a genetic disorder and could by renamed as hereditary shunt hyperbilirubinaemia.

Role of detection of microsatellite instability in Chinese with hereditary nonpolyposis colorectal cancer or ordinary hereditary colorectal cancer

AIM： To detect microsatellite instability （MSI） in patients with hereditary nonpolyposis colorectal cancer or ordinary hereditary colorectal cancer and to provide criteria for screening the kindreds with hereditary nonpolyposis colorectal cancer at molecular level.METHODS： MSI was detected in the specimens from 20 cases with HNPCC, 20 cases with ordinary hereditary colorectal cancer and 20 cases with sporadic colorectal cancer by means of polymerase chain reaction-single strand conformation polymorphism. RESULTS： The positive rate of MSI was 85% （17/20） in HNPCC group, 40% （8/20） in ordinary hereditary colorectal cancer group and 10% （2/20） in the sporadic colorectal cancer group respectively. The differences were significant. The mean ages of the three groups were 43.6, 52.2, and 61.8 years respectively, which increased gradually. The incidence of right hemicolon cancer was 64.7%, 37.5%, and 0% respectively, which decreased gradually and had significant difference. The expression ratio of BAT26 and BAT25 was 94.1% respectively, which was highest in the 5 gene sites studied. The incidence of poorly differentiated adenocarcinoma was 70.6% in HNPCC group among high frequency microsatellite instability （MSI-H）, which was higher than the other two groups, which had 50% and 50% respectively. CONCLUSION： The incidence of MSI-H is higher in HNPCC group. The detection of MSI is simple and economical and has high correlation with the clinicopathologic feature of HNPCC and can be used as a screening method to detect the germ line mutation of the mismatch repair gene.

Hepcidin levels in hereditary hyperferritinemia:Insights into the iron-sensing mechanism in hepatocytes

AIM:To study the role of hepcidin in hereditary hyperferritinemia cataract syndrome(HHCS). METHODS:Six patients from two families with HHCS, confirmed by genetic analysis showing A to G mutation at position+40 in the L-ferritin gene,were recruited to undergo serum hepcidin and prohepcidin measurements using radioimmunoassay and enzyme linked immunoassay,respectively,and measurements were compared with levels in serum from 25 healthy volunteers(14 females),mean age 36±11.9 years.RESULTS:The serum hepcidin and prohepcidin levels in patients with HHCS were 19.1±18.6 and 187± 120.9 ng/mL,respectively.Serum ferritin was 1716.3± 376μg/L.Liver biopsy in one patient did not show any evidence of iron overload.Serum hepcidin and prohepcidin values in healthy controls(HCs)were 15.30±15.71 and 236.88±83.68 ng/mL,respectively,while serum ferritin was 110±128.08μg/L.There was no statistical difference in serum hepcidin level between the two cohorts(19.1±18.6 ng/mL vs 15.30±15.71 ng/mL,P= 0.612)using two-tailed t-test. CONCLUSION:Serum hepcidin levels in HHCS patients is similar to that in HCs.Our study suggests that circulating ferritin is not a factor influencing hepcidin synthesis and does not have a role in the iron-sensing mechanism in hepatocytes.

Identification of a Novel VEGFR-3 Missense Mutation in a Chinese Family with Hereditary Lymphedema Type I

A novel mutation of vascular endothelial growth factor receptor gene （VEGFR-3）, was identified in a four-generation Chinese family with hereditary lymphedema type I （HL-I）. Genetic linkage analysis was performed on the known genetic locus for HL-I with a panel of polymorphic markers, and then mutations were screened out by direct sequencing. By genotyping, the family showed the linkage to HL-I locus on 5q35.3. Mutation screening analysis of the exons encoding the intracellular kinase domains of VEGFR-3, revealed a novel missense mutation D1055V. This mutation cosegregated with the disease phenotype in the family and was not found in 100 normal controls. This finding has expanded the spectrum of the VEGFR-3 gene mutations causing HL-I, and will be useful for further genetic consultation and genetic diagnosis.

Hereditary Behavior of bar Gene Cassette is Complex in Rice Mediated by Particle Bombardment

Particle bombardment transformation using minimal gene cassette （containing the promoter, open reading frame and terminator） is the novel trend in plant genetic transformation, and its use helps to alleviate the undesirable effects of plasmid vector backbone sequences on transgenic plants. In the present article, studies related to the hereditary behavior of bar gene cassette in T1 to T3 generations of the transgenic rice （Oryza sativa L.） lines transformed by particle bombardment have been discussed. The selectable marker bar gene cassette that integrated with the rice genome had multiple copies and showed complex segregation behaviors including the presence of ‘false homozygotes’, with abnormal segregation ratios ranging from 35：1 to 144：1 （Basta-resistant： sensitive plants） in their progenies. In five out of ten original transgenic lines, bar gene can be stably transmitted as a dominant gene to self-pollinated T2 progeny. The homozygotes were obtained in three transgenic lines in T1 generation regardless of the multiple-copy integration patterns of bar gene. Southern blotting analysis showed that multiple copies of bar gene cassette were linked, which formed transgene arrays in the host rice genome. The authors also observed stable transmission of integration patterns of bar gene cassette, as obtained from Southern blotting analysis, in the regularly segregated transgenic rice lines and loss of gene in an irregularly segregated transgenic line. The segregation behavior varied among the transgenic progenies that exhibited similar Southern hybridization patterns of bar gene. On the basis of these results, the multiple-copy integration, gene lost, and gene expres- sion interaction were the major reasons for the complex segregation behaviors of bar gene cassette in transgenic rice plants.

Lynch syndrome and Lynch syndrome mimics: The growing complex landscape of hereditary colon cancer

Hereditary non-polyposis colorectal cancer(HNPCC) was previously synonymous with Lynch syndrome; however,identification of the role of germline mutations in the DNA mismatch repair(MMR) genes has made it possible to differentiate Lynch syndrome from other conditions associated with familial colorectal cancer(CRC). Broadly,HNPCC may be dichotomized into conditions that demonstrate defective DNA MMR and microsatellite instability(MSI) vs those conditions that demonstrate intact DNA MMR. Conditions characterized by MMR deficient CRCs include Lynch syndrome(germline MMR mutation),Lynch-like syndrome(biallelic somatic MMR mutations),constitutional MMR deficiency syndrome(biallelic germline MMR mutations),and sporadic MSI CRC(somatic biallelic methylation of MLH1). HNPCC conditions with intact DNA MMR associated with familial CRC include polymerase proofreading associated polyposis and familial colorectal cancer type X. Although next generation sequencing technologies have elucidated the genetic cause for some HNPCC conditions,others remain genetically undefined. Differentiating between Lynch syndrome and the other HNPCC disorders has profound implications for cancer risk assessment and surveillance of affected patients and their at-risk relatives. Clinical suspicion coupled with molecular tumor analysis and testing for germline mutations can help differentiate the clinical mimicry within HNPCC and facilitate diagnosis and management.

Germline mutation analysis of hPMS2 gene in Chinese families with hereditary nonpolyposis colorectal cancer

AIM: To study the germline mutation of hPMS2 gene in 26 unrelated Chinese hereditary nonpolyposis colorectal cancer (HNPCC) probands and to fulfill the screening strategy for HNPCC in Chinese. METHODS: Genomic DNA was extracted from the peripheral blood. To avoid the interference of pseudogene in detection of the remaining 11 exons (exon 1-5, 9, 11-15), long-range polymerase chain reaction (PCR) was conducted to amplify the complete coding region of hPMS2 gene firstly. Then 1/8 of the PCR productswere used as template to amplify the individual exon respectively and DNA sequencing was done. Direct DNA sequencing of the conventional PCR products of exon 6, 7, 8 and 10 of hPMS2 gene was performed. The same analysis was made in 130 healthy persons without family histories of HNPCC to further investigate the pathological effects of the detected missense mutation. RESULTS: One HNPCC proband fulf illed Bethesda guidelines and was found to carry the germline mutation of hPMS2 gene, which has not been reported in Chinese HNPCC families. It was a missense mutation at c.1532C>T of exon 11. It was detected in three controls as well with an occurrence rate of 2.3% (3/130). Since it could not be found in the PMS2-single nucleotide polymorphism (SNP) database, this missense mutation is a new SNP unreported up to date. Meanwhile, 260 reported SNPs of hPMS2 gene were detected in the 26 HNPCC probands. The 2nd and 5th exons were probably the hot SNP regions of hPMS2 gene in Chinese HNPCC families involving 53.1% of all reported SNP. CONCLUSION: The germline mutation of hPMS2 gene may be rare in Chinese HNPCC families. The 2nd and 5th exons are hot SNP regions of hPMS2 gene.

Hereditary diffuse gastric cancer: What the clinician should know

Hereditary diffuse gastric cancer(HDGC) is an inherited autosomal dominant syndrome with a penetrance of up to 80% affecting diverse geographic populations. While it has been shown to be caused mainly by germline alterations in the E-cadherin gene(CDH1), problematically, the genetic diagnosis remains unknown in up to 60% of patients. Given the important knowledge gaps regarding the syndrome, asymptomatic carriers of CDH1 mutations are advised for a prophylactic total gastrectomy. Intensive annual endoscopic surveillance is the alternative for carriers who decline gastrectomy. As HDGCs have a prolonged indolent phase, this provides a window of opportunity for surveillance and treatment. Recent findings of other gene defects in CTNNA1 and MAP3K6, as well as further characterization of CDH1 mutations and their pathogenicity will change the way HDGC patients are counselled for screening, surveillance and treatment. This review will bring the reader up to date with these changes and discuss future directions for research; namely more accurate risk stratification and surveillance methods to improve clinical care of HDGC patients.

Mitochondrial variants may influence the phenotypic manifestation of Leber's hereditary optic neuropathy-associated ND4 G11778A mutation

We report here the characterization of a five-generation Han Chinese family with Leber＇s hereditary optic neuropathy （LHON）. Strik- ingly, this Chinese family displayed high penetrance and expressivity of visual loss. The average age-of-onset of vision loss was 18 years in this family. Nineteen （11 males/8 females） of 29 matrilineal relatives in this family developed visual loss with a wide range of severity, ranging from blindness to normal vision. Sequence analysis of mitochondrial genome in this pedigree revealed the presence of the ND4 G 11778A mutation and 44 other variants belonging to Asian haplogroup M7b. The G 11778A mutation is present at homoplasmy in matri- lineal relatives of this Chinese family. Of other variants, the C01 G6480A, ND5 T12811C and Cytb A15395G located at highly conserved residues of corresponding polypeptides. In fact, these variants were implicated to be involved in other clinical abnormalities. Here, these variants may act in synergy with the primary LHON-associated Gl1778A mutation. Thus, the mitochondrial dysfunction caused by the primary ND4 G11778A mutation may be worsened by these mitochondrial variants. The results imply that the G6480A, T12811C and A15395G variants might have a potential modifier role in increasing the penetrance and expressivity of the primary LHON-associated G11778A mutation in this Chinese family.

Stem Cell Ophthalmology Treatment Study (SCOTS)： bone marrow-derived stem cells in the treatment of Leber＇s hereditary optic neuropathy

The Stem Cell Ophthalmology Treatment Study （SCOTS） is currently the largest-scale stem cell ophthal- mology trial registered at ClinicalTrials.gov （identifier： NCT01920867）. SCOTS utilizes autologous bone marrow-derived stem cells （BMSCs） to treat optic nerve and retinal diseases. Treatment approaches include a combination of retrobulbar, subtenon, intravitreal, intra-optic nerve, subretinal, and intravenous injection of autologous BMSCs according to the nature of the disease, the degree of visual loss, and any risk factors related to the treatments. Patients with Leber＇s hereditary optic neuropathy had visual acuity gains on the Early Treatment Diabetic Retinopathy Study （ETDRS） of up to 35 letters and Snellen acuity improvements from hand motion to 20/200 and from counting fingers to 20/100. Visual field improvements were noted. Macular and optic nerve head nerve fiber layer typically thickened. No serious complications were seen. The increases in visual acuity obtained in our study were encouraging and suggest that the use of autolo- gous BMSCs as provided in SCOTS for ophthalmologic mitochondrial diseases including Leber＇s hereditary optic neuropathy may be a viable treatment option.

Pulmonary hypertension in hereditary haemorrhagic telangiectasia

Hereditary haemorrhagic telangiectasia(HHT) is an autosomal dominant inherited disorder characterised by vascular malformations in predominantly the brain,liverand lungs.Pulmonary hypertension(PH) is increasingly recognised as a severe complication of HHT.PH may be categorised into two distinct types in patients with HHT.Post-capillary PH most often results from a high pulmonary blood flow that accompanies the high cardiac output state associated with liver arteriovenous malformations.Less frequently,the HHT-related gene mutations in ENG or ACVRL1 appear to predispose patients with HHT to develop pre-capillary pulmonary arterial hypertension.Differentiation between both forms of PH by right heart catheterisation is essential,since both entities are associated with severe morbidity and mortality with different treatment options.Therefore all HHT patients should be referred to an HHT centre.

Molecular signaling mechanisms of apoptosis in hereditary non-polyposis colorectal cancer

Colorectal cancer is the second most leading cause of cancer related deaths in the western countries. One of the forms of colorectal cancer is hereditary non-polyposis colorectal cancer (HNPCC), also known as "Lynch syndrome". It is the most common hereditary form of cancer accounting for 5%-10% of all colon cancers. HNPCC is a dominant autosomal genetic disorder caused by germ line mutations in mismatch repair genes. Human mismatch repair genes play a crucial role in genetic stability of DNA, the inactivation of which results in an increased rate of mutation and often a loss of mismatch repair function. Recent studies have shown that certain mismatch repair genes are involved in the regulation of key cellular processes including apoptosis. Thus, differential expression of mismatch repair genes particularly the contributions of MLH1 and MSH2 play important roles in therapeutic resistance to certain cytotoxic drugs such as cisplatin that is used normally as chemoprevention. An understanding of the role of mismatch repair genes in molecular signaling mechanism of apoptosis and its involvement in HNPCC needs attention for further work into this important area of cancer research, and this review article is intended to accomplish that goal of linkage of apoptosis with HNPCC. The current review was not intended to provide a comprehensive enumeration of the entire body of literature in the area of HNPCC or mismatch repair system or apoptosis; it is rather intended to focus primarily on the current state of knowledge of the role of mismatch repair proteins in molecular signaling mechanism of apoptosis as it relates to understanding of HNPCC.

Intraductal papillary mucinous neoplasm of the ileal heterotopic pancreas in a patient with hereditary non-polyposis colorectal cancer: A case report

We report a case of intraductal papillary mucinous neoplasm(IPMN) originating from the ileal heterotopic pancreas in a patient with hereditary non-polyposis colorectal cancer(HNPCC). A 49-year-old woman had a past history of total colectomy and total hysterectomy with bilateral salpingo-oophorectomy due to colonic adenocarcinoma and endometrial adenocarcinoma 11 years ago. Her parents died from colonic adenocarcinoma and her sister died from colonic adenocarcinoma and endometrial adenocarcinoma. The clinician found an ileal mass with necrotic change and the mass increased in size from 1.7 cm to 2.2 cm during the past 2 years on computed tomography. It was surgically resected. Microscopically, the ileal mass showed heterotopic pancreas with IPMN high grade dysplasia. Immunohistochemical staining revealed positive reactivity for MLH1/PMS2 and negative reactivity for MSH2/MSH6. This is the first report of IPMN originating from the ileal heterotopic pancreas in a patient with HNPCC in the English literature.