Very low HDL levels: clinical assessment and management

ABSTRACT In individuals with very low high-density lipoprotein (HDL-C) cholesterol, such as Tangier disease, LCAT deficiency, and familial hypoalphalipoproteinemia, there is an increased risk of premature atherosclerosis. However, analyzes based on comparisons of populations with small variations in HDL-C mediated by polygenic alterations do not confirm these findings, suggesting that there is an indirect association or heterogeneity in the pathophysiological mechanisms related to the reduction of HDL-C. Trials that evaluated some of the HDL functions demonstrate a more robust degree of association between the HDL system and atherosclerotic risk, but as they were not designed to modify lipoprotein functionality, there is insufficient data to establish a causal relationship. We currently have randomized clinical trials of therapies that increase HDL-C concentration by various mechanisms, and this HDL-C elevation has not independently demonstrated a reduction in the risk of cardiovascular events. Therefore, this evidence shows that (a) measuring HDL-C as a way of estimating HDL-related atheroprotective system function is insufficient and (b) we still do not know how to increase cardiovascular protection with therapies aimed at modifying HDL metabolism. This leads us to a greater effort to understand the mechanisms of molecular action and cellular interaction of HDL, completely abandoning the traditional view focused on the plasma concentration of HDL-C. In this review, we will detail this new understanding and the new horizon for using the HDL system to mitigate residual atherosclerotic risk.

Establishment and evaluation of the polygenic disease risk prediction model / 上海预防医学

To establish a disease risk prediction model based on genetic susceptibility genes and environmental risk factors， which can target high-risk population as early as possible， and intervene in the environmental risk factors in this population. Moreover， accurate screening of genetically susceptible populations can enhance the efficiency of health system. In recent years， with the maturation and cost reduction of high-throughput gene testing， gene testing has been widely used in individual clinical decision-making and will play a more important role in medical and health decision-making. The correlation between genetic testing and disease risk prediction is increasing， making it a prominent research topic in this field. This review summarizes the approaches for establishing and evaluating risk prediction models and discusses potential future challenges and opportunities.

PARÁMETROS GENÉTICOS DE CARACTERÍSTICAS BIOMÉTRICAS DEL FRUTO Y SEMILLA EN Caesalpinia ébano (FABACEAE) / Genetic parameters of fruit and seed biometric characteristics in Caesalpinia ebano (Fabaceae)

RESUMEN El objetivo del estudio fue evaluar los parámetros genéticos de las características biométricas del fruto y semillas de Caesalpinia ebano. La investigación se realizó en Montería (Colombia), se seleccionaron diez árboles, y de cada uno diez frutos tomados al azar. Se realizaron análisis de varianza y estimación de parámetros genéticos para nueve características: peso fresco del fruto, largo del fruto, ancho del fruto, grosor del fruto, número de semillas/fruto, peso de semillas por fruto, peso de una semilla, volumen de una semilla y densidad de una semilla. Se detectaron diferencias estadísticas (p < 0,01) entre árboles, para todas las características, excepto para el ancho del fruto y peso de una semilla; denotando la existencia de variabilidad genética entre los árboles para peso del fruto, largo del fruto, grosor del fruto, número de semillas y densidad de una semilla. El peso y largo del fruto presentaron la heredabilidad media familiar y heredabilidad en el sentido estricto con los valores más altos (h2 Fam > 82 % y h2 E > 30 %). La ganancia genética esperada fue mayor del 10 % en cinco de las nueve características estudiadas, y mayor del 20 % para número de semillas y peso de las semillas (27,31 y 27,87 %, respectivamente). Los caracteres peso y largo del fruto se podrían transmitir a las generaciones sucesivas, con mayor posibilidad de éxito, mediante la selección fenotípica de árboles.

ABSTRACT The objective of the study was to evaluate the genetic parameters of the biometric characteristics of the fruit and seeds of C. ebano. The investigation was carried out in Montería, Córdoba (Colombia); ten trees were selected and from each, ten fruits taken at random. Variance analysis and estimation of genetic parameters for nine traits were carried out: fresh fruit weight, fruit length, fruit width, fruit thickness, number of seeds/fruit, weight of seeds by fruit, weight of one seed, volume of one seed and density of one seed. Statistical differences (p < 0.01) were detected between trees, for all traits except for width of the fruit and weight of a seed; denoting the existence of genetic variability between trees for fruit weight, fruit length, fruit thickness, number of seeds and density of a seed. The weight and length of the fruit presented the highest family heritability and narrow sense heritability (h2 Fam > 82 % and h2 E> 30 %). The expected genetic gain was greater than 10 % in five of the nine studied traits, and greater than 20 % for number of seeds and weight of seeds (27.31 and 27.87 %, respectively). The traits fruit weight and length could be transmitted to successive generations, with greater chance of success, by phenotypic selection of trees.

Phenotype of definite familial hypercholesterolemia with negative genetic study in Argentina / Fenotipo de hipercolesterolemia familiar definitivo con estudio genético negativo en Argentina

Abstract Objective: Familial hypercholesterolemia (FH) is a monogenic disease, associated with variants in the LDLR, APOB and PCSK9 genes. The initial diagnosis is based on clinical criteria like the DLCN criteria. A score > 8 points qualifies the patient as "definite" for FH diagnosis. The detection of the presence of a variant in these genes allows carrying out familial cascade screening and better characterizes the patient in terms of prognosis and treatment. Methods: In the context of the FH detection program in Argentina (Da Vinci Study) 246 hypercholesterolemic patients were evaluated, 21 with DLCN score > 8 (definite diagnosis).These patients were studied with next generation sequencing to detect genetic variants, with an extended panel of 23 genes; also they were adding the large rearrangements analysis and a polygenic score of 10 SNP (single nucleotide polymorphism) related to the increase in LDL-c. Results: Of the 21 patients, 10 had variants in LDLR, 1 in APOB with APOE, 1 in LIPC plus elevated polygenic score, and 2 patients showed one deletion and one duplication in LDLR, the later with a variation in LIPA. It is highlighted that 6 of the 21 patients with a score > 8 did not show any genetic alteration. Conclusions: We can conclude that 28% of the patients with definite clinical diagnosis of FH did not show genetic alteration. The possible explanations for this result would be the presence of mutations in new genes, confusing effects of the environment over the genes, the gene-gene interactions, and finally the impossibility of detecting variants with the current available methods.

Resumen Objetivo: La hipercolesterolemia familiar (HF) es una enfermedad monogénica asociada a variantes en los genes RLDL, APOB y PCSK9. El diagnóstico inicial se basa en criterios clínicos, como el de la red de clínica de lípidos holandesa (DLCN). Un puntaje > 8 puntos califica al paciente como "definitivo" para diagnóstico de HF. La identificación de una variante en estos genes permite realizar el cribado en cascada familiar y caracterizar mejor al paciente en cuanto al pronóstico y el tratamiento. Métodos: En el marco del Programa de Detección de HF en Argentina (Estudio Da Vinci) se evaluó a 246 pacientes hipercolesterolémicos, 21 con puntaje DLCN > 8 (diagnóstico definitivo). Se estudió a estos pacientes con secuenciación de próxima generación para reconocer variantes genéticas, con un panel ampliado de 23 genes, sumado al análisis de grandes rearreglos y por último se aplicó un score poligénico de 10 SNP (polimorfismo de nucleótido único) relacionados con aumento del c-LDL. Resultados: De los 21 pacientes, 10 presentaron variantes en RLDL, uno en APOB junto a APOE, uno en LIPC más puntaje poligénico elevado, dos pacientes con una deleción y una duplicación en RLDL y este último caso con una variante en LIPA. Es destacable que 6 de los 21 pacientes con puntaje DLCN > 8 no mostraron ninguna alteración genética. Conclusiones: El 28% de los pacientes con diagnóstico clínico definitivo de HF no evidenció alteración genética. Las posibles explicaciones de este resultado serían la presencia de mutaciones en nuevos genes, los efectos confundidores del ambiente sobre los genes o la interacción gen-gen y por último la imposibilidad de detectar variantes con la metodología actual disponible.

Association of Polygenic Risk Score with Age at Onset and Cerebrospinal Fluid Biomarkers of Alzheimer's Disease in a Chinese Cohort / 神经科学通报·英文版

To evaluate whether the polygenic profile modifies the development of sporadic Alzheimer's disease (sAD) and pathological biomarkers in cerebrospinal fluid (CSF), 462 sAD patients and 463 age-matched cognitively normal (CN) controls were genotyped for 35 single-nucleotide polymorphisms (SNPs) that are significantly associated with sAD. Then, the alleles found to be associated with sAD were used to build polygenic risk score (PRS) models to represent the genetic risk. Receiver operating characteristic (ROC) analyses and the Cox proportional hazards model were used to evaluate the predictive value of PRS for the sAD risk and age at onset. We measured the CSF levels of Aβ42, Aβ42/Aβ40, total tau (T-tau), and phosphorylated tau (P-tau) in a subgroup (60 sAD and 200 CN participants), and analyzed their relationships with the PRSs. We found that 14 SNPs, including SNPs in the APOE, BIN1, CD33, EPHA1, SORL1, and TOMM40 genes, were associated with sAD risk in our cohort. The PRS models built with these SNPs showed potential for discriminating sAD patients from CN controls, and were able to predict the incidence rate of sAD and age at onset. Furthermore, the PRSs were correlated with the CSF levels of Aβ42, Aβ42/Aβ40, T-tau, and P-tau. Our study suggests that PRS models hold promise for assessing the genetic risk and development of AD. As genetic risk profiles vary among populations, large-scale genome-wide sequencing studies are urgently needed to identify the genetic risk loci of sAD in Chinese populations to build accurate PRS models for clinical practice.

Establishment and validation of OX40/FcγR-humanized mice for the study of agonistic anti-OX40 antibody / 上海交通大学学报（医学版）

Objective • To establish a rapid method to evaluate the activity of agonistic antibody using OX40 (tumor necrosis factor receptor superfamily member 4)/FcγR (Fcγ receptor)-humanized mice. Methods • Bone marrow cells from OX40-humanized mice and FcγR-humanized mice were collected and mixed with equal ratio. Then the mixed bone marrow cells were administrated into irradiated wild-type mice through the tail veins. The reconstruction efficiency of the immune system was confirmed by detecting the expression of hOX40 and hFcγR in the immune cells of chimera mice. After the chimera mice were generated successfully, they were used to evaluate the immunostimulatory activity of anti-hOX40 antibodies to CD4+ or CD8+ T cells. The results of flow cytometry were statistically analyzed. The unpaired t-test was used to compare the means between the two groups, and oneway ANOVA was used to compare the means between multiple groups. Results • Flow cytometry analysis showed that wild-type recipient mice were efficiently reconstituted with hFcγR expressing cells and hOX40 expressing cells to generate OX40/FcγR-humanized bone marrow chimera mice. In these mice, B cells and myeloid cells expressed hFcγRs (P<0.05), and T cells expressed hOX40 upon in vitro stimulation (P<0.05). When these mice were used to evaluate the immunostimulatory activity of anti-hOX40 antibody, significant expressions of IFN-γ and hOX40 were observed (P<0.05). Conclusion • OX40/FcγR-humanized bone marrow chimera mice are generated based on hFcγR expressing cells and hOX40 expressing cells, suggesting a rapid method to build a mouse model with both hFcγR and hOX40 expression. These mice are suitable for evaluating the immunostimulatory activity of agonistic human anti-hOX40 antibodies.

Exploratory analysis of polygenic risk scores for psychiatric disorders: Applied to dual diagnosis

Background Concurrence of substance use disorders (SUDs) is high in individuals with psychiatric illnesses; more importantly, individuals with both disorders (dual diagnosis) have more severe symptoms. Psychiatric disorders have been proposed to share a genetic susceptibility with SUDs. To explore this shared genetic susceptibility, we analyzed whether any of the polygenic risk scores (PRSs) for psychiatric disorders could be associated to dual diagnosis in patients with schizophrenia (SCZ) or bipolar disorder (BD). Methods We included 192 individuals of Mexican ancestry: 72 with SCZ, 53 with BD, and 67 unrelated controls without psychiatric disorders. We derived calculations of PRS for autism spectrum disorders, attention-deficit/hyperactive disorder, BD, major depression, and SCZ using summary genome-wide association statistics previously published. Results We found that dual diagnosis had a shared genetic susceptibility with major depressive disorder (MDD) and SCZ; furthermore, in individuals with BD, dual diagnosis could be predicted by PRS for MDD. Conclusions Our results reinforce the notion that individuals with dual diagnosis have a higher genetic susceptibility to develop both disorders. However, analyses of larger sample sizes are required to further clarify how to predict risks through PRS within different populations.

Application of polygenic risk scores in risk prediction and precision prevention of complex diseases: opportunities and challenges / 中华流行病学杂志

Along with the rapid progress in the field of human genomics, genome-wide association studies have successfully identified numerous risk loci for complex diseases. Polygenic risk scores can predict disease risk by integrating the effects of multiple susceptibility loci, and begin to show good performance for improving risk prediction, screening strategy and precision prevention. This paper briefly reviews the recent progress of polygenic risk scores in disease prevention, and summarizes the opportunities and challenges of its application.

Agregación familiar en pacientes con hipertensión arterial / Family Aggregation in Patients with Arterial Hypertension

Introducción: actualmente, la hipertensión arterial es considerada como un trastorno poligénico y multifactorial, en el cual la interacción de múltiples genes entre sí y con el medio ambiente es importante. Objetivos: describir el comportamiento de la agregación familiar de la hipertensión arterial. Métodos: se realizó un estudio observacional, descriptivo, de corte transversal en el Policlínico Alex Urquiola en el periodo de enero a agosto de 2016. El universo de estudio estuvo constituido por los 54 pacientes y la muestra por 20, seleccionados a través de muestreo de tipo probabilístico aleatorio simple. Se les aplicó una encuesta estructurada y se realizó análisis informático de los resultados. Resultados: el grupo etario predominante fue el de 50 a 59 años (55 por ciento); mientras que el grupo menos representado fue el de 30 a 39 años (10 por ciento). En cuanto al grado de parentesco con los familiares hipertensos, predominaron los que tenían familiares de II grado (55 por ciento). El sedentarismo predominó como factor de riesgo. Conclusiones: se demostró agregación familiar para la hipertensión arterial en estas familias. Predominaron el grado de parentesco II y el factor de riesgo sedentarismo. Considerándose importante la prevención primaria en cada área de salud, para poder modificar factores de riesgo(AU)

Introduction: Hypertension is nowadays considered a polygenic and multifactorial disorder, in which the interaction of multiple genes with one other and with the environment is important. Objectives: To describe the behavior of family aggregation of arterial hypertension. Methods: An observational, descriptive, cross-sectional study was performed Alex Urquiola Polyclinic, from January to August 2016. The study universe consisted of 54 patients and the sample consisted of 20 patients, chosen by simple probabilistic randomization. They were given a structured survey, after which we carried out the computerized analysis of the results. Results: The predominant age group was 50-59 years (55 percent), while the least represented group corresponded to the ages 30-39 years (10 percent). As for the degree of kinship to hypertensive relatives, there was a predominance of those who had relatives of grade II (55 percent). The sedentary lifestyle predominated as a risk factor. Conclusions: Family aggregation for hypertension was proved in these families. The was a predominance of the second degree of relation and sedentary risk factors. We consider that primary prevention is important in each health area, for the modification of risk factors(AU)

Genetics of obesity: an overview of current approaches and advancement.

Elucidation of obesity susceptibility genes through genome wide approaches as well as candidate gene approaches provides great promise in ultimately determining the genetic underpinnings of obesity. The complex nature of human obesity stems from the multiple interaction of several genes that control the physiology of food intake, energy expenditure, development of the body, and behavioural patterns towards food intake, and the environment. According to twin, adoptees and family studies, genetic factors account for 40-70% of the variability observed in human adiposity. Twin studies supported that the heritability of adiposity is higher than other quantitative traits. The heritability of obesity traits has been further evidenced by identification of quantitative trait loci (QTL) and genes through methods such as genome-wide scans (studies conducted on unrelated obese individuals), linkage analyses (conducted in families), and association studies (investigating the correlation between obesity and polymorphisms). The number of contributing genes, however, is still unknown. Although research on the genetic basis of obesity has advanced, the mechanisms underlying the condition are still complex due to its heterogeneity even within families.

¿Qué hay de nuevo en el síndrome de ovario poliquístico? / What’s new in polycystic ovary syndrome

Polycystic ovary syndrome is recognized as a risk factor for the development of type 2 diabetes and metabolic syndrome. The prevalence of the condition is 6 to 10 percent in different populations. Its etiology is not well known and there are genetic and epigenetic phenomena involved. Due to its association with insulin resistance, it has been incorporated as another component of Reaven plurimetabolic syndrome. Therefore polycystic ovary syndrome evolved from an ovarian disease to a multisystem disorder and it must be considered a public health problem.

Psoriasis lineal y vitiligo segmentario, manifestación sobrepuesta de dos enfermedades frecuentes / Lineal psoriasis and segmental vitiligo overlapped. Presentation of two frequent conditions

La asociación de psoriasis y vitiligo es un evento bien documentado, con una incidencia del 3%, según diferentes series de casos, aunque no hallamos trabajos de superposición de ambas enfermedades siguiendo las líneas de Blaschko, en la literatura revisada por nosotros. Presentamos el caso de una mujer de 47 años de edad con lesiones de vitiligo en rostro y en abdomen, desde la infancia, que se distribuyeron sobre las líneas de Blaschko; después de 30 años aparecieron placas eritematoescamosas sobre las manchas acrómicas del abdomen, que clínica e histopatológicamente correspondieron a psoriasis y mejoraron parcialmente con fototerapia UVB de banda estrecha. La psoriasis y el vitiligo son entidades multifactoriales, poligénicas, que pueden exhibir patrones de mosaicismo cutáneo. Se han planteado algunas teorías para explicar este fenómeno, pero todavía no son conocidos todos los factores que influyen en este tipo de presentación.

The association of psoriasis and vitiligo is a well documented event, with an incidence of 3% according to different case series, but reports of an overlap of both diseases following Blaschko lines were not found in the reviewed literature. We present the case of a 47 years old woman with vitiligo lesions in the face and abdomen, starting since childhood, distributed over the Blaschko lines; thirty years later erythematous and squamous plaques appeared over the achromic macules of the abdominal region which were clinically and histopathologically compatible with psoriasis and improved partially with narrow band UVB phototherapy. Psoriasis and vitíligo are multifactorial and polygenic skin disorders that can show patterns of cutaneous mosaicism. Some theories have tried to explain this phenomenon, but the factors that influence this presentation are still unclear.

Study on genetic epidemic of ankylosing spondylitis / 国际儿科学杂志

Objective To investigate the epidemiological situation and the mode of inheritance of ankylosing spondylitis (AS).Methods The AS prevalence investigation was carried out from three different areas in Shandong Province to investigate the incidence of the 80 patients' family members of sick group and calculate the heritability of AS.Results After the investigation and calculation we found the incidence of primary relatives was 7.23％,the heritability was 85.94％,the incidence of secondary relatives was 0.94％ and the heritability was 57.4％,the incidence of thirdly relatives was 0.39％,the heritability is 36.2％,the average heritability among primary,secondary and thirdly was 68.47％ ± 1.64％.Separation ratio was 0.088 9.Conclusion AS is a polygenic disease,its average heritability was 68.47％ ± 1.64％ and separation ratio is 0.088 9.By this research,the incidence risk of AS patients' pedigree offspring can be assessed,then strengthen protective factors to reduce the incidence of the disease to provide the basis for eugenics.

La etiología de la esquizofrenia / The etiology of schizophrenia

Las investigaciones realizadas en los últimos años iniciaron una nueva era de conocimiento de los factores de riesgo de la esquizofrenia. Por otra parte, los métodos de estudio del genoma completo han revolucionado el campo del mapeado genético de la esquizofrenia. Estudios genéticos recientes sugieren que la variación genética rara y la variación genética común tienen una función importante en la arquitectura genética de la esquizofrenia, que el modelo poligénico es correcto, e indican una superposición de los factores genéticos que confieren susceptibilidad a la esquizofrenia y otros trastornos psiquiátricos, como el trastorno bipolar y el autismo (pleotropía). Los programas de resecuenciación del genoma completo permitirán una disección más profunda de la genética molecular de la enfermedad. Uno de los desafíos importantes de la psiquiatría genética es la traducción de las asociaciones estadísticas detectadas en estudios de genoma completo en una mejor comprensión fisiopatológica de la esquizofrenia.

Research conducted in recent years represents a new dawn of knowledge for the risk factors of schizophrenia, and genome-wide approaches have revolutionized the field of genetic mapping of schizophrenia. The aggregate genetic data increasingly support a combination of rare and common genetic variation in schizophrenia, a major role for polygenic inheritance, and a genetic overlap (pleiotropy) of schizophrenia and other psychiatric disorders, such as bipolar disorder and autism. A main challenge for the field is the translation of established genetic associations into a better pathophysiological understanding of schizophrenia. The current and upcoming resequencing programs - both exomes (all exons) and full genomes - and genome-wide transcriptional analyses will allow a more thorough dissection of the molecular genetics of the disorder.

Resistance of tomato genotypes to the greenhouse whitefly Trialeurodes vaporariorum (West.) (Hemiptera: Aleyrodidae)

The greenhouse whitefly, Trialeurodes vaporariorum Westwood, is the most common and abundant whitefly in Argentine horticultural greenhouse crops, especially in tomato (Solanum lycopersicum). Resistance in some wild tomato relatives, such as S. peruvianum, S. habrochaites and S. pennellii to the greenhouse whitefly has been described. The Mi gene confers effective resistance against several species of insects, among them the sweet potato whitefly, Bemisia tabaci Gennadius. Resistance to T. vaporariorum was found in the prebreeding line FCN 93-6-2, derived from a cross between S. lycopersicum cultivar Uco Plata INTA (MiMi) and the wild line FCN 3-5 S. habrochaites. The purpose of this study was to evaluate resistance to T. vaporariorum in tomato genotypes and to study the relationship between this resistance and the presence of the REX-1 marker, which is linked to the Mi gene. In a free-choice assay, the average number of adults per leaf and the number of immatures on the middle and basal plant parts were analyzed. In a no-choice assay, the oviposition rate and adult survival rate were calculated. For all variables analyzed, FCN 3-5 was the most resistant strain. Variations were found in the F2 progeny between the prebreeding line FCN 13-1-6-1 and cv. Uco Plata INTA. Results from the F2 progeny indicate that resistance to T. vaporariorum may be polygenic with transgressive segregation. Whitefly resistance was found to be independent of the REX-1 marker.

Genetic Approach to Human Obesity / 대한소아내분비학회지

Increasing rate of childhood obesity is one of the social health problems in Korea. The mechanisms of fat accumulation and maintenance are not clear yet. Genetic, environmental, behavioral and socioeconomic factors in individuals might cause very heterogenous phenotypic expressions of obesity. In the aspect of genetic factors, there are two types of obesity; monogenic (single mutations) and polygenic obesity (known as common obesity). The completion of human genome project contributed to genetic study for obesity and many candidate genes associated with obesity were found in the past couple of years. However, the functional study of those genes was little performed. The trials to reveal the effect of each gene are required, because the more genes are studied, the better the mechanisms of obesity can be understood.

Cytogenetics and Polygenic Factor Analysis of 364 Female Children with Short Stature / 实用儿科临床杂志

Objective To explore the effect of chromosomal abnormality and polygenic inheritance factor in female children with short stature.Methods 1.Chromosome analysis:peripheral blood was drawn for 1 mL and cultured 72 h to analyze chromosome karyotype (Giemsa Banding ) of peripheral lymphocytes.2.Polygenic factor analysis:the children′s final height were estimated based on their parents average height,and analyzed the distribution characteristics of children′s final height and compared the estimate final height with the actual height.Results Eighty-three cases out of the 364 female children with short stature were chromosomal abnormality(22.80%).Among the 83 cases,the 45,XO and 46,X,i(Xq) occupied 70%.The distribution of children target height shifted left,and the target height of 76 cases was lower than 2 standard deviation (-2 s)and the consistency of target height and actual height reached 20.88%.The target height of 7 cases was lower than 2 standard deviation in those whose chromosome turned out to be abnormal,and the consistency of target height and actual height was 8.43%.Conclusions Chromosomal abnormality is one of the most important etiologic agents causing short stature in female children, and polygenic inheritance is another important etiologic agent.

The Genetics of Vitiligo in Korean Patients / 대한피부과학회지

BABCKGROUND: Vitiligo is a cornmon disorder whose cause is not well understood. Up to 30% of patients had another family member with vitiligo which means that vitiligo is a heritable condition. We could not find any study for the genetics of vitiligo in Korean literature. OBJECTIVE: The purpose of this study was to clarify how genetic factors are involved in the pathogenesis of vitiligo in Korean patients. METHODS: We analyzed the 65 Korean vitiligo probands and their families. Each family was ascertained through a proband afflicted with vitiligo. RESULTS: 1. Focal type of vitiligo(44.6%) appeared to be with the highest frequency followed by the non-segmental generalized type(35.4%) and segmental type(20.0%). 2. The t,ype of vitiligo was not related with sex (p>0.9, X(2)(d.l=2) = 0.14). 3. There was a clear pattern of a familial aggregation of the vitiligo disease. In 29(44.6%) of these 65 proband families, at least one first-degree relative of the proband had vitiligo. The incidence of people affected among their 789 relatives (first, second and third-degree) was also found to be 9.13+/-1.03% 4. Several families in this study were shown to have father-son transmission of vitiligo, which indicates that vitiligo does not fit an x-linked inheritance. 5. There is a statistically significant departure frorn the expected which is inconsistent with a utosomal dominant inheritance (p<0.001, X(2)(d.l=2) = 52.32). 6. A single recessive model at the autosomal locus is not an explanation in deter mining the cause of vitiligo. The threshold trait among first-degree relatives(8.8%) shows a tendency to approach the square root of the frequency in the general population(10%) compared to those of dominant(50%) or recessive(25%) models. This result is consistent with a model of multifactorial inheritence for vitiligo. CONCLUSION: These result indicate that vitiligo is determined by a polygenic nature.

Study on HLA Susceptible Haplotype of Psoriasis in 23 Families / 中华皮肤科杂志

This article reports the results of HLA antigen distribution in 23 families with multiple affected siblings alld 59 unrelated patients with psoriasis vulgaris. The frequency of HLA - A19, B13 and DR7 was significantly higher(Pc 0. 001) than that of controls. It seems that the lower frequency of C7 and DQ1 is resistant to the development of psoriasis. Fifty -five health siblings in 23 families were observed for six to eight years. 20 out of 55 siblings had one or two same HLA haplotypes. Among the 20 persons, 4 siblings had psoriasis vulgaris,35 out of 55 siblings had no similar HLA haplotype and have not affected with psoriasis vulgaris up to now. It shows that HLA haplotype determination is helpful for the clinical surveillance of their healthy sibling with susceptible haplotype.

A study on pathogenesis and inheritance risk of congenital mental retardation / 重庆医科大学学报

Objective:To investigate the genetic factors relating to mental retardation (MR).Methods:We have analysed 840 cases of congenital mental retardation with biochemistry lab tests,cytogenetic study and family investigation.Results:21 cases were due to monogenic disorders (2.50%);216 cases were due to chromosomal diseases (25.71%);13 cases were due to polygenic disorders (1.55%);590 cases were due to unknown causes (70.24%).Conclusion:It suggested that occurrence of mental retardation is related to both genetic factors and environmental factors.