在阿舍尔综合征中,新型USH2A变异的体质马赛克主义
Cheng-Yao Zheng1, Yu-Ying Jiang1, Hong Chen1
1Eye Institute, Affiliated Hospital of Nantong University, Medical School of Nantong University, Nantong, Jiangsu, China.
Ophthalmic genetics
|March 10, 2026
概括
这项研究报告了一种罕见的阿舍尔综合征II型病例,由体质马赛克引起,而不是典型的孟德尔遗传. 研究结果强调在零星情况下考虑马赛克主义,以获得准确的遗传咨询.
科学领域:
- 遗传学 遗传学 是一个
- 眼科医生 眼科 眼科
- 听力学 听力学是指听力学.
背景情况:
- 艾舍尔综合征II型是一种遗传性疾病,导致听力和视力丧失.
- 零星病例往往会带来诊断上的挑战.
- 在受孕后发生遗传突变的体质马赛克主义是遗传疾病的罕见原因.
研究的目的:
- 详细介绍一个零星的阿舍尔综合征II型病例的临床和遗传发现.
- 为了研究体质马赛克主义在患者病情中的作用.
- 为改善遗传咨询提供证据.
主要方法:
- 进行全面的眼科和听力学检查.
- 下一代测序和桑格测序用于遗传分析.
- 超深度测序和STR分析以检测和确认体质马赛克主义.
主要成果:
- 在USH2A中发现了一种新的同卵性无意义突变.
- 超深度测序揭示了高突变等位基因频率 (98.2%),表明体质马赛克主义.
- STR分析支持了马赛克主义的存在,与简单的孟德尔遗传不一致.
结论:
- 这一案例表明,阿舍尔综合征II型的罕见遗传机制涉及体质马赛克.
- 这些发现扩大了USH2A中已知的突变,并完善了基因型-表型相关性.
- 考虑到体质马赛克主义对于零星的阿舍尔综合征病例的精确遗传咨询至关重要.
相关概念视频
Pleiotropy
43.8K
Pleiotropy is the phenomenon in which a single gene impacts multiple, seemingly unrelated phenotypic traits. For example, defects in the SOX10 gene cause Waardenburg Syndrome Type 4, or WS4, which can cause defects in pigmentation, hearing impairments, and an absence of intestinal contractions necessary for elimination. This diversity of phenotypes results from the expression pattern of SOX10 in early embryonic and fetal development. SOX10 is found in neural crest cells that form melanocytes,...
43.8K
Position-effect Variegation
7.2K
In 1928, a German botanist Emil Heitz observed the moss nuclei with a DNA binding dye. He observed that while some chromatin regions decondense and spread out in the interphase nucleus, others do not. He termed them euchromatin and heterochromatin, respectively. He proposed that the heterochromatin regions reflect a functionally inactive state of the genome. It was later confirmed that heterochromatin is transcriptionally repressed, and euchromatin is transcriptionally active chromatin.
7.2K
Meiosis I
221.0K
Meiosis is a carefully orchestrated set of cell divisions, the goal of which—in humans—is to produce haploid sperm or eggs, each containing half the number of chromosomes present in somatic cells elsewhere in the body. Meiosis I is the first such division, and involves several key steps, among them: condensation of replicated chromosomes in diploid cells; the pairing of homologous chromosomes and their exchange of information; and finally, the separation of homologous chromosomes by...
221.0K
Genomic Imprinting and Inheritance
38.3K
Diploid organisms inherit genetic material through chromosomes from both parents. Copies of the same gene are known as alleles. In most cases, both alleles are simultaneously expressed and allow various cellular processes to function optimally. If one of the alleles is missing or mutated, the expression of the other allele can compensate; however, this is not true for all genes.
The expression of some genes depends on which parent passed the gene to the offspring, through a phenomenon known as...
The expression of some genes depends on which parent passed the gene to the offspring, through a phenomenon known as...
38.3K
Nondisjunction
83.0K
During meiosis, chromosomes occasionally separate improperly. This occurs due to failure of homologous chromosome separation during meiosis I or failed sister chromatid separation during meiosis II. In some species, notably plants, nondisjunction can result in an organism with an entire additional set of chromosomes, which is called polyploidy. In humans, nondisjunction can occur during male or female gametogenesis and the resulting gametes possess one too many or one too few chromosomes.
83.0K
Nondisjunction
5.5K
Nondisjunction is the failure of homologous chromosomes or sister chromatids to separate correctly and move to the opposite poles of the cells. This produces daughter cells with abnormal chromosome numbers. Nondisjunction is common during anaphase I or anaphase II of meiosis. Mutations in synaptonemal complex proteins that attach homologous chromosomes increase the chances of nondisjunction in anaphase I of meiosis I. In contrast, mutations in topoisomerases and condensins that hold...
5.5K


