高乳酸血症-卒中样发作综合征型线粒体脑肌病一家系两代四例报告

线粒体脑肌病属于罕见性母系遗传病，本文回顾性分析了1家4例高乳酸血症-卒中样发作综合征（MELAS）型线粒体脑肌病患者，其主要表现为卒中样发作、头痛、癫痫、高乳酸血症、肌肉不耐受疲劳、高级智能下降、听力下降和身材矮小等，结合特征性影像学变化、基因检测及肌肉活检明确诊断，并结合文献对只有女儿能将其线粒体DNA（mt-DNA）传递给下一代的母系遗传MELAS型线粒体脑肌病临床特点进行了总结分析，旨在帮助临床认识此病，进一步提高MELAS型线粒体脑肌病的临床诊断率。     

Foot Polydactyly and Polysyndactyly: Genetic Implications in Two Families

The purpose of this study was to determine the genetic characteristics of foot polydactyly and identify its inheritance pattern by analyzing familial pedigree. Five cases from 2 Korean families were studied: 1 is a family whose members have been affected for 4 generations and the other for 2 generations. Using peripheral blood samples, we performed chromosomal analysis using the banding technique with Giemsa stain and karyotyping. We investigated the shape and structure of 46 chromosomes, looking for translation, deletion, inversion, ring chromosome, and isochromosome abnormalities. All peripheral blood samples demonstrated no chromosomal abnormalities, though the genetic nature of foot polydactyly and a new genetic locus was identified recently by other studies. Familial pedigree analysis suggested that polydactyly was inherited as an autosomal dominant trait in the first family. The mode of inheritance for the second family could not be determined due to an insufficient number of family members. The result of this study brought us to the conclusion that, while genetic factors play a major role in polydactyly, other factors may contribute to its occurrence.     

Goldenhar 综合征家系的临床表型和遗传学分析

目的分析1组Goldenhar综合征家系的临床表现及遗传学特征。方法我们随访到1组4代33人的Goldenhar综合征家系，对目前存活的29人进行了临床表型和遗传学的初步分析。结果家系内有Goldenhaar综合征患者5人．临床表现具高度多样性，累及眼、耳、脊柱、颜面、口腔等多个器官和系统的发育不良，在遗传方式上属于常染色体显性遗传。从细胞遗传学水平对家系中成员进行染色体检查，未发现核型异常。结论该Goldenhar综合征家系属常染色体显性遗传，染色体检查未发现核型异常。     

一个进行性肌营养不良症家系的研究

目的寻找由DNA损伤(如突变)引起的人类表型缺陷,为人类遗传资源的收集与保藏以及人类基因结构与功能的研究打下基础。方法通过实地调查得到表型缺陷家系,然后进行系谱分析。结果得到一进行性肌营养不良家系,4代41位成员中有12例患者。结论进行性肌营养不良是由DNA损伤引起的人类表型缺陷;该病症符合常染色体显性遗传;该病的发生具有一定的外显率和表现度。     

A nuclear mutant of Chlamydomonas that exhibits increased sensitivity to UV irradiation,reduced recombination of nuclear genes,and altered transmission of chloroplast genes

Summary Meiotic progeny of Chlamydomonas reinhardtii normally receive chloroplast genomes only from the mt ⁺ parent. However, exceptional zygotes, which transmit the chloroplast genomes of both parents or, more rarely, only those of the mt ^- parent, arise at a low frequency. Mutations at the mt ⁺-linked mat-3 locus were found previously to elevate the transmission of chloroplast genomes from the mt-parent, resulting in a much higher than normal frequency of exceptional zygotes. In this paper we demonstrate that an ultraviolet-sensitive nuclear mutation mapping at the uvsE1 locus, which is unlinked to mating type, also promotes chloroplast genome transmission from the mt ^- parent. This mutant, which was previously shown to reduce recombination of nuclear genes in meiosis, acts synergistically which the mat3-3 mutation to produce an extremely high frequency of exceptional zygotes. Through the use of restriction fragment length polymorphisms existing in the chloroplast genomes of C. reinhardtii and the interfertile strain C. smithii, we show that chloroplast DNA fragments from the mt ^- parent normally begin to disappear shortly after zygote formation. However, this process appears to be blocked totally in the absence of wild-type uvsE1 and mat-3 gene products. Our findings are consistent with the hypothesis that both gene products contribute to the mechanism responsible for uniparental inheritance of the chloroplast genome from the mt ⁺ parent.     

Autosomal recessive blepharoptosis,cleft lip/palate,dental anomalies,and ectrodactyly

Fluorescence in situ hybridization (FISH) with α-satellite DNA probes was used to study whole-arm chromosome translocation products in a family in which the propositus was shown to have a monosomy 18p/trisomy 20p imbalance. By this approach, we show that the chromosome 18 α-satellite DNA block is split into 2 smaller units, whereas the chromosome 20 breakpoint is not included within the α-satellite DNA region. We found no evidence to suggest that this split α-satellite DNA region has reduced or impaired the function of the centromere or that it contributed to the phenotype of the propositus. The FISH technique critically demonstrated the involvement of a whole-arm translocation in this case and provided accurate identification of breakpoints, which was not possible with standard banding techniques. © Wiley-Liss, Inc.     

Alternative graphical representations of genotypes in a pedigree

Three representations of the conditional independences due toMendelian segregation of genes in a pedigree are proposed. Thecomputational costs of performing calculations using the techniqueof peeling with each of these representations is compared byconsidering the weights of triangulations of the graph producedby each representation.     

Parental consanguinity in two sibs with omodysplasia

Two sibs with omodysplasia were born to phenotypically normal but consanguineous parents. They had severe micromelic dwarfism, facial anomalies, and mental retardation. One had a congenital heart defect. The radiographic findings are typical: hypoplastic distal end of the humerus with radioulnar diastasis. Parental consanguinity and clinical manifestations in 2 sibs suggest autosomal recessive inheritance. © 1994 Wiley-Liss, Inc.     

Hypothalamic-pituitary-gonadal function in two infants with Smith-Lemli-Opitz syndrome

We report on the hypothalamic-pituitary-gonadal function in 2 male infants with the Smith-Lemli-Opitz (SLO or RSH) syndrome. Both infants had abnormal external genitalia. Basal and LHRH stimulated plasma gonadotropins were normal for age (1 month). Plasma testosterone, androstenedione, and dehydroepiandrosterone sulfate were normal for age and sex. Some forms of congenital adrenal hyperplasia (17,20-desmolase deficiency, 17α-hydroxylase deficiency, and 3β-hydroxysteroid dehydrogenase deficiency) were ruled out by hormonal studies. The endocrinological findings indicate a normal hypothalamic-pituitary-gonadal function and a normal adrenal steroid biosynthesis in these 2 patients. A partial androgen receptor defect causing the genital malformations seems possible in one patient. Whether 5α-reductase deficiency is the cause of the male pseudohermaphroditism in SLO syndrome remains the subject of future studies. © 1992 Wiley-Liss, Inc.