Background Hirschsprung's disease(HSCR)is one of the most common congenital digestive tract malformations and can cause stubborn constipation or gastrointestinal obstruction after birth,causing great physical and ...Background Hirschsprung's disease(HSCR)is one of the most common congenital digestive tract malformations and can cause stubborn constipation or gastrointestinal obstruction after birth,causing great physical and mental pain to patients and their families.Studies have shown that more than 20 genes are involved in HSCR,and most cases of HSCR are sporadic.However,the overall rate of familial recurrence in 4331 cases of HSCR is about 7.6%.Furthermore,familial HSCR patients show incomplete dominance.We still do not know the penetrance and genetic characteristics of these known risk genes due to the rarity of HSCR families.Methods To find published references,we used the title/abstract terms"Hirschsprung"and"familial"in the PubMed data-base and the MeSH terms"Hirschsprung"and"familial"in Web of Science.Finally,we summarized 129 HSCR families over the last 40 years.Results The male-to-female ratio and the percentage of short segment-HSCR in familial HSCR are much lower than in sporadic HSCR.The primary gene factors in the syndromic families are ret proto-oncogene(RET)and endothelin B receptor gene(EDNRB).Most families show incomplete dominance and are relevant to RET,and the RET mutation has 56%pen-etrance in familial HSCR.When one of the parents is a RET mutation carrier in an HSCR family,the offspring's recurrence risk is 28%,and the incidence of the offspring does not depend on whether the parent suffers from HSCR.Conclusion Our findings will help HSCR patients obtain better genetic counseling,calculate the risk of recurrence,and provide new insights for future pedigree studies.展开更多
Epistasis is a ubiquitous phenomenon in genetics,and is considered to be one of main factors in current efforts to unveil missing heritability of complex diseases.Simulation data is crucial for evaluating epistasis de...Epistasis is a ubiquitous phenomenon in genetics,and is considered to be one of main factors in current efforts to unveil missing heritability of complex diseases.Simulation data is crucial for evaluating epistasis detection tools in genome-wide association studies(GWAS).Existing simulators normally suffer from two limitations:absence of support for high-order epistasis models containing multiple single nucleotide polymorphisms(SNPs),and inability to generate simulation SNP data independently.In this study,we proposed a simulator SimHOEPI,which is capable of calculating penetrance tables of high-order epistasis models depending on either prevalence or heritability,and uses a resampling strategy to generate simulation data independently.Highlights of SimHOEPI are the preservation of realistic minor allele frequencies in sampling data,the accurate calculation and embedding of high-order epistasis models,and acceptable simulation time.A series of experiments were carried out to verify these properties from different aspects.Experimental results show that SimHOEPI can generate simulation SNP data independently with high-order epistasis models,implying that it might be an alternative simulator for GWAS.展开更多
The development of colorectal cancer(CRC)can be influenced by genetic factors in both familial cases and sporadic cases.Familial CRC has been associated with genetic changes in high-,moderate-and low-penetrance suscep...The development of colorectal cancer(CRC)can be influenced by genetic factors in both familial cases and sporadic cases.Familial CRC has been associated with genetic changes in high-,moderate-and low-penetrance susceptibility genes.However,despite the availability of current gene-identification techniques,the genetic causes of a considerable proportion of hereditary cases remain unknown.Genome-wide association studies of CRC have identified a number of common lowpenetrance alleles associated with a slightly increased or decreased risk of CRC.The accumulation of low-risk variants may partly explain the familial risk of CRC,and some of these variants may modify the risk of cancer in patients with mutations in high-penetrance genes.Understanding the predisposition to develop CRC will require investigators to address the following challenges:the identification of genes that cause uncharacterized hereditary cases of CRC such as familial CRC type X and serrated polyposis;the classification of variants of unknown significance in known CRC-predisposing genes;and the identification of additional cancer risk modifiers that can be used to perform risk assessments for individual mutation carriers.We performed a comprehensive review of the genetically characterized and uncharacterized hereditary CRC syndromes and of lowand moderate-penetrance loci and variants identified through genome-wide association studies and candidate-gene approaches.Current challenges and future perspectives in the field of CRC predisposition are also discussed.展开更多
AIM:To determine the amount of ultraviolet(UV)light irradiance that various layers of the eye receive as sunlight passes through the eye,and to investigate the protective benefits of UV light-blocking contact lenses.M...AIM:To determine the amount of ultraviolet(UV)light irradiance that various layers of the eye receive as sunlight passes through the eye,and to investigate the protective benefits of UV light-blocking contact lenses.METHODS:Twenty-four porcine eyes were prepared in one of three ways:isolated cornea,cornea and lens together,or whole eye preparation.UV light irradiance was measured with a UV-A/B light meter before and after the eye preparations were placed over the meter to measure UV light penetration in each eye structure.In the whole eye preparation,a hole was placed in the fovea to measure light as it passed through the vitreous.Subsequently,UVprotective contact lenses were placed over the structures,and UV light penetrance was measured.Measurements of UV light exposure were taken outdoors at various locations and times.RESULTS:Cornea absorbed 63.56%of UV light that reached the eye.Cornea and lens absorbed 99.34%of UV light.Whole eye absorbed 99.77%of UV light.When UV-protective contact lenses were placed,absorption was 98.90%,99.55%,and 99.87%,respectively.UV light exposure was dependent on directionality and time of day,and was greatest in areas of high albedo that reflect significant amounts of light,such as a beach.CONCLUSION:Cornea absorbs the majority of UV light that reaches the eye in this model.UV-protective contact lenses reduce UV exposure to the eye.Locations with high albedo expose the eye to higher levels of UV light.展开更多
Purpose: The past decade has seen rapid acceleration in the public’s access to Whole Genome Sequencing (WGS) technology, however, factors that may influence a person’s decision to undergo this complex health screeni...Purpose: The past decade has seen rapid acceleration in the public’s access to Whole Genome Sequencing (WGS) technology, however, factors that may influence a person’s decision to undergo this complex health screening have received little empirical attention. This is the first psychosocial study to investigate which disease and individual-based factors predict intention to undergo WGS. Methods: A total of 164 first-year university students responded to hypothetical disease scenarios (varied by disease penetrance and treatment availability) and completed self-report measures of individual factors. Results: Intention to undergo WGS was significantly higher in the presence of available treatment and high disease penetrance (p p p < 0.05). Conclusions: Treatability and disease penetrance appear to be two distinct motivations that can also interact to influence intention to pursue WGS. Task self-efficacy, positive outcome expectancies and uncertainty avoidance are likely to motivate intention to pursue WGS in young healthy adults. These findings will be useful in informing the optimal design of WGS psycho-educational resources and screening provider protocols.展开更多
A genetic association between single nucleotide polymorphisms (SNPs) and pulmonary hypertension syndrome (PHS) was established in a commercial population of broiler chickens. The associated SNPs were found in the NOS3...A genetic association between single nucleotide polymorphisms (SNPs) and pulmonary hypertension syndrome (PHS) was established in a commercial population of broiler chickens. The associated SNPs were found in the NOS3 and HIF1α genes (LOD > 6;p NOS3 gene interfere with its trans-activation and transcriptional activation activities under natural hypobaric hypoxia conditions and are located in a consensus sequence that is called the hypoxia response element (HRE). SNPs located in the HIF1α gene could act as alternative cryptic splicing sites in intron six, which may stimulate non-sense mediated early decay (NMD) of the primary transcript. A fragment of intron 3 of the EDN1 gene was also evaluated, but the polymorphisms found were not associated with PHS (lod 0.001). However, further studies on the regulatory transcription sequences of EDN1 are recommended. The findings of this study indicate that intronic sequences should be included when searching for polymorphisms that produce physiological changes. Introns have transcriptional regulatory sequences or post-transcriptional control signals, which are known as cis- and trans-activation regulatory elements and are able to alter the physiological processes of hypoxia adaptation when modified. Based on these findings, it can be concluded that the inheritance pattern of PHS is autosomal overdominant and has deleterious effects that are characterized by higher penetrance in heterozygous than in homozygous animals, which prevent broiler chickens from being able to adapt to high altitudes.展开更多
Objectives To formulate an equation for fine mapping of disease loci under complex conditions and determine the marker-disease distance in a specific case using this equation. Methods Lewontin’s linkage disequi...Objectives To formulate an equation for fine mapping of disease loci under complex conditions and determine the marker-disease distance in a specific case using this equation. Methods Lewontin’s linkage disequilibrium (LD) measure D’ was used to formulate an equation for mapping disease genes in the presence of phenocopies, locus heterogeneity, gene-gene and gene-environment interactions, incomplete penetrance, uncertain liability and threshold, incomplete initial LD, natural selection, recurrent mutation, high disease allele frequency and unknown mode of inheritance. This equation was then used to determine the distance between a marker (ε4 within the apolipoprotein E gene, APOE) and Alzheimer’s disease (AD) loci using published data.Results An equation was formulated for mapping disease genes under the above conditions. If these conditions are present but ignored, then recombination fraction θ between marker and disease loci will be either overestimated or estimated with little bias. Therefore, an upper limit of θ can be obtained. AD has been found to be associated with the marker allele ε4 in Africans, Asians, and Caucasians. This suggests that the AD-ε4 allelic LD predates the divergence of peoples occurring 100?000 years ago. With the age of AD-ε4 allelic LD so estimated, the maximal distance was calculated to be 23.2 kb (mean 5.8 kb). Conclusions (1) A method is developed for LD mapping of susceptibility genes. (2) A mutation within the APOE gene itself, among others, is responsible for the susceptibility to AD, which is supported by recent evidence from studies using transgenic mice.展开更多
基金National Natural Science Foundation of China(82071685 to FJX)Clinical Research Pilot Project of Tongji Hospital(2019YBKY026 to FJX)+2 种基金Provincial Key Research and Development Program(2020BCB008 to FJX)Science and Technology Innovation Base Platform(2020DCD006 to FJX)Project of Shenzhen San Ming(SZSM201812055 to FJX).
文摘Background Hirschsprung's disease(HSCR)is one of the most common congenital digestive tract malformations and can cause stubborn constipation or gastrointestinal obstruction after birth,causing great physical and mental pain to patients and their families.Studies have shown that more than 20 genes are involved in HSCR,and most cases of HSCR are sporadic.However,the overall rate of familial recurrence in 4331 cases of HSCR is about 7.6%.Furthermore,familial HSCR patients show incomplete dominance.We still do not know the penetrance and genetic characteristics of these known risk genes due to the rarity of HSCR families.Methods To find published references,we used the title/abstract terms"Hirschsprung"and"familial"in the PubMed data-base and the MeSH terms"Hirschsprung"and"familial"in Web of Science.Finally,we summarized 129 HSCR families over the last 40 years.Results The male-to-female ratio and the percentage of short segment-HSCR in familial HSCR are much lower than in sporadic HSCR.The primary gene factors in the syndromic families are ret proto-oncogene(RET)and endothelin B receptor gene(EDNRB).Most families show incomplete dominance and are relevant to RET,and the RET mutation has 56%pen-etrance in familial HSCR.When one of the parents is a RET mutation carrier in an HSCR family,the offspring's recurrence risk is 28%,and the incidence of the offspring does not depend on whether the parent suffers from HSCR.Conclusion Our findings will help HSCR patients obtain better genetic counseling,calculate the risk of recurrence,and provide new insights for future pedigree studies.
基金This work was supported by the National Natural Science Foundation of China(Nos.61972226 and 62172254).
文摘Epistasis is a ubiquitous phenomenon in genetics,and is considered to be one of main factors in current efforts to unveil missing heritability of complex diseases.Simulation data is crucial for evaluating epistasis detection tools in genome-wide association studies(GWAS).Existing simulators normally suffer from two limitations:absence of support for high-order epistasis models containing multiple single nucleotide polymorphisms(SNPs),and inability to generate simulation SNP data independently.In this study,we proposed a simulator SimHOEPI,which is capable of calculating penetrance tables of high-order epistasis models depending on either prevalence or heritability,and uses a resampling strategy to generate simulation data independently.Highlights of SimHOEPI are the preservation of realistic minor allele frequencies in sampling data,the accurate calculation and embedding of high-order epistasis models,and acceptable simulation time.A series of experiments were carried out to verify these properties from different aspects.Experimental results show that SimHOEPI can generate simulation SNP data independently with high-order epistasis models,implying that it might be an alternative simulator for GWAS.
基金The Spanish Ministry of the Economy(State Secretariat for Research,Development and Innovation),grant SAF2012-38885Ramon y Cajal contract+1 种基金L’Oreal-UNESCO"For Women in Science"and the Scientific Foundation Asociacion Espanola Contra el Cancer
文摘The development of colorectal cancer(CRC)can be influenced by genetic factors in both familial cases and sporadic cases.Familial CRC has been associated with genetic changes in high-,moderate-and low-penetrance susceptibility genes.However,despite the availability of current gene-identification techniques,the genetic causes of a considerable proportion of hereditary cases remain unknown.Genome-wide association studies of CRC have identified a number of common lowpenetrance alleles associated with a slightly increased or decreased risk of CRC.The accumulation of low-risk variants may partly explain the familial risk of CRC,and some of these variants may modify the risk of cancer in patients with mutations in high-penetrance genes.Understanding the predisposition to develop CRC will require investigators to address the following challenges:the identification of genes that cause uncharacterized hereditary cases of CRC such as familial CRC type X and serrated polyposis;the classification of variants of unknown significance in known CRC-predisposing genes;and the identification of additional cancer risk modifiers that can be used to perform risk assessments for individual mutation carriers.We performed a comprehensive review of the genetically characterized and uncharacterized hereditary CRC syndromes and of lowand moderate-penetrance loci and variants identified through genome-wide association studies and candidate-gene approaches.Current challenges and future perspectives in the field of CRC predisposition are also discussed.
基金Supported by Research to Prevent Blindness,New York,NY,USA。
文摘AIM:To determine the amount of ultraviolet(UV)light irradiance that various layers of the eye receive as sunlight passes through the eye,and to investigate the protective benefits of UV light-blocking contact lenses.METHODS:Twenty-four porcine eyes were prepared in one of three ways:isolated cornea,cornea and lens together,or whole eye preparation.UV light irradiance was measured with a UV-A/B light meter before and after the eye preparations were placed over the meter to measure UV light penetration in each eye structure.In the whole eye preparation,a hole was placed in the fovea to measure light as it passed through the vitreous.Subsequently,UVprotective contact lenses were placed over the structures,and UV light penetrance was measured.Measurements of UV light exposure were taken outdoors at various locations and times.RESULTS:Cornea absorbed 63.56%of UV light that reached the eye.Cornea and lens absorbed 99.34%of UV light.Whole eye absorbed 99.77%of UV light.When UV-protective contact lenses were placed,absorption was 98.90%,99.55%,and 99.87%,respectively.UV light exposure was dependent on directionality and time of day,and was greatest in areas of high albedo that reflect significant amounts of light,such as a beach.CONCLUSION:Cornea absorbs the majority of UV light that reaches the eye in this model.UV-protective contact lenses reduce UV exposure to the eye.Locations with high albedo expose the eye to higher levels of UV light.
文摘Purpose: The past decade has seen rapid acceleration in the public’s access to Whole Genome Sequencing (WGS) technology, however, factors that may influence a person’s decision to undergo this complex health screening have received little empirical attention. This is the first psychosocial study to investigate which disease and individual-based factors predict intention to undergo WGS. Methods: A total of 164 first-year university students responded to hypothetical disease scenarios (varied by disease penetrance and treatment availability) and completed self-report measures of individual factors. Results: Intention to undergo WGS was significantly higher in the presence of available treatment and high disease penetrance (p p p < 0.05). Conclusions: Treatability and disease penetrance appear to be two distinct motivations that can also interact to influence intention to pursue WGS. Task self-efficacy, positive outcome expectancies and uncertainty avoidance are likely to motivate intention to pursue WGS in young healthy adults. These findings will be useful in informing the optimal design of WGS psycho-educational resources and screening provider protocols.
文摘A genetic association between single nucleotide polymorphisms (SNPs) and pulmonary hypertension syndrome (PHS) was established in a commercial population of broiler chickens. The associated SNPs were found in the NOS3 and HIF1α genes (LOD > 6;p NOS3 gene interfere with its trans-activation and transcriptional activation activities under natural hypobaric hypoxia conditions and are located in a consensus sequence that is called the hypoxia response element (HRE). SNPs located in the HIF1α gene could act as alternative cryptic splicing sites in intron six, which may stimulate non-sense mediated early decay (NMD) of the primary transcript. A fragment of intron 3 of the EDN1 gene was also evaluated, but the polymorphisms found were not associated with PHS (lod 0.001). However, further studies on the regulatory transcription sequences of EDN1 are recommended. The findings of this study indicate that intronic sequences should be included when searching for polymorphisms that produce physiological changes. Introns have transcriptional regulatory sequences or post-transcriptional control signals, which are known as cis- and trans-activation regulatory elements and are able to alter the physiological processes of hypoxia adaptation when modified. Based on these findings, it can be concluded that the inheritance pattern of PHS is autosomal overdominant and has deleterious effects that are characterized by higher penetrance in heterozygous than in homozygous animals, which prevent broiler chickens from being able to adapt to high altitudes.
文摘Objectives To formulate an equation for fine mapping of disease loci under complex conditions and determine the marker-disease distance in a specific case using this equation. Methods Lewontin’s linkage disequilibrium (LD) measure D’ was used to formulate an equation for mapping disease genes in the presence of phenocopies, locus heterogeneity, gene-gene and gene-environment interactions, incomplete penetrance, uncertain liability and threshold, incomplete initial LD, natural selection, recurrent mutation, high disease allele frequency and unknown mode of inheritance. This equation was then used to determine the distance between a marker (ε4 within the apolipoprotein E gene, APOE) and Alzheimer’s disease (AD) loci using published data.Results An equation was formulated for mapping disease genes under the above conditions. If these conditions are present but ignored, then recombination fraction θ between marker and disease loci will be either overestimated or estimated with little bias. Therefore, an upper limit of θ can be obtained. AD has been found to be associated with the marker allele ε4 in Africans, Asians, and Caucasians. This suggests that the AD-ε4 allelic LD predates the divergence of peoples occurring 100?000 years ago. With the age of AD-ε4 allelic LD so estimated, the maximal distance was calculated to be 23.2 kb (mean 5.8 kb). Conclusions (1) A method is developed for LD mapping of susceptibility genes. (2) A mutation within the APOE gene itself, among others, is responsible for the susceptibility to AD, which is supported by recent evidence from studies using transgenic mice.
