背景:关于20q13.33区域内基因型-表型相关性的阐明,已经进行了有限的研究。20q13.33微缺失的基因型-表型关联仍未得到充分理解。在本研究中,介绍了两例20q13.33微缺失的新病例,目的是增强对基因型-表型关系的理解。
方法:本研究纳入了两名来自中国东南部福建省的具有各种异常临床表型的无关患者。进行核型分析和染色体微阵列分析(CMA)以研究染色体异常和拷贝数变异。
结果:高分辨率G显带核型分析的结果得出46,XY,der(20)在患者1中添加(20)(q13.3)。该患者表现出各种临床表现,例如全球发育迟缓,智力残疾,癫痫发作,和其他先天性疾病。随后,在20q13.33区域中鉴定出1.0Mb缺失,在14q32.31q32.33区域中鉴定出5.2Mb重复。在患者2中,CMA结果显示20q13.33区域中有1.8Mb缺失,有4.8Mb重复17q25.3。患者表现出额外的异常临床特征,包括小阴茎,先天性心脏病,和一种独特的哭泣模式,其特征是弯曲的嘴巴。
结论:在本研究中,第一次,在中国人群的17q25.3和14q32.31q32.33地区,对两例具有微重复的20q13.33微缺失新病例进行了调查。微阴茎的存在可能归因于20q13.33微缺失,可能扩大与此缺失相关的表型谱。
BACKGROUND: Limited research has been conducted regarding the elucidation of genotype-phenotype correlations within the 20q13.33 region. The genotype-phenotype association of 20q13.33 microdeletion remains inadequately understood. In the present study, two novel cases of 20q13.33 microdeletion were introduced, with the objective of enhancing understanding of the genotype-phenotype relationship.
METHODS: Two unrelated patients with various abnormal clinical phenotypes from Fujian province Southeast China were enrolled in the present study. Karyotype analysis and chromosomal microarray analysis (CMA) were performed to investigate chromosomal abnormalities and copy number variants.
RESULTS: The results of high-resolution G-banding karyotype analysis elicited a 46,XY,der(20)add(20)(q13.3) in Patient 1. This patient exhibited various clinical manifestations, such as global developmental delay, intellectual disability, seizures, and other congenital diseases. Subsequently, a 1.0-Mb deletion was identified in the 20q13.33 region alongside a 5.2-Mb duplication in the 14q32.31q32.33 region. In Patient 2, CMA results revealed a 1.8-Mb deletion in the 20q13.33 region with a 4.8-Mb duplication of 17q25.3. The patient exhibited additional abnormal clinical features, including micropenis, congenital heart disease, and a distinctive crying pattern characterized by a crooked mouth.
CONCLUSIONS: In the present study, for the first time, an investigation was conducted into two novel cases of 20q13.33 microdeletion with microduplications in the 17q25.3 and 14q32.31q32.33 regions in the Chinese population. The presence of micropenis may be attributed to the 20q13.33 microdeletion, potentially expanding the phenotypic spectrum associated with this deletion.