涉及6q染色体区域的间质缺失很少见。迄今为止,已经描述了不到30名患者,高分辨率技术的特点较少,如染色体微阵列。涉及6q21q22.1区域的缺失与极其广泛和异质的临床谱相关,因此,基于重排区域的大小和相关基因的基因型-表型相关性是复杂的,甚至在有重叠缺失的个体中。在这里,我们描述了一个发育迟缓的女孩的新6q间质缺失的表型和分子特征,智力残疾,小脑疣发育不全,面部特有的特征,共济失调和眼部异常。该基因的微阵列分析显示,在6q21q22.1染色体区域有7.9Mb的间隙从头缺失,从核苷酸108,337,770到116,279,453(GRCh38/hg38)。本案,在对文献进行系统回顾的同时,提供了进一步的证据,可以帮助定义最小重叠区域和与特定表型相关的基因组性状,专注于神经系统的发现,尤其是小脑异常。
Interstitial deletions involving 6q chromosomal region are rare. Less than 30 patients have been described to date, and fewer have been characterized by high-resolution techniques, such as chromosomal microarray. Deletions involving 6q21q22.1 region are associated with an extremely wide and heterogeneous clinical spectrum, thus genotype-phenotype correlation based on the size of the rearranged region and on the involved genes is complex, even among individuals with overlapping deletions. Here we describe the phenotypic and molecular characterization of a new 6q interstitial deletion in a girl with developmental delay, intellectual disability, cerebellar vermis hypoplasia, facial peculiar characteristics, ataxia and ocular abnormalities. Microarray analysis of the proposita revealed a 7.9 Mb interstitial de novo deletion at 6q21q22.1 chromosomal region, which spanned from nucleotides 108,337,770 to 116,279,453 (GRCh38/hg38). The present case, alongside with a systematic
review of the literature, provides further evidence that could aid to the definition of the Smallest Region of Overlap and of the genomic traits that are associated with particular phenotypes, focusing on neurological findings and especially on cerebellar anomalies.