6号环状染色体致隐匿性阴茎1例报告及文献复习

Ring chromosome 6 causing concealed penis: a case report and literature review

目的探讨6号环状染色体片段缺失与临床表型的关系。方法报道1例因隐匿性阴茎就诊男性患儿,通过常规染色体核型和全基因组染色体微阵列芯片技术,分析缺失片段位置及包含基因与临床表型的关系;同时进行文献复习。结果患儿染色体核型分析结果为6号环状染色体,全基因组染色体微阵列芯片检测发现,6号染色体短臂和长臂末端均存在缺失,del6p25.3p25.1.seq[GRCh37/hg39](204909-4210858)×1,del6q27.seq[GRCh37/hg39](170438227-170898549)×1,短臂p25区域缺失4.01 Mb,包含DUSP22、IRF4、EXOC2、HUS1B、LOC285768、FOXQ1、FOXF2、FOXC1等30个基因,而长臂6q27区域发生0.46 Mb缺失,包含LOC154449、DLL1、FAM120B、PSMB1、TBP、PDCD2等7个基因。分析比较本例患儿和文献报道的6号环状染色体病例,发现所有患儿均存在神经或生长发育障碍,但仅本例和另1例患儿有生殖道畸形。结论 6号环状染色体患者的临床表型与染色体缺失部位、缺失片段大小以及环状染色体稳定性密切相关。

Objective To explore the relationship between the missing fragments in ring chromosome 6 and the clinical phenotype.Method A male patient with concealed penis was reported.The relationship between the location of missing fragments and the clinical phenotypes was analyzed by routine chromosome karyotype and genome-wide chromosome microarray technology.Meanwhile,the literature was reviewed.Results The patient was diagnosed of a ring chromosome 6 by karyotype analysis.Genome chromosome microarray detection showed that there were defects in both the short arm and the end of the long arm of chromosome 6,del6p25.3p25.1.seq[GRCh37/hg39](204909-4210858)×1,del6q27.seq[GRCh37/hg39](170438227-170898549)×1.A 4.01 Mb deletion was found in short arm P25 region,involving 30 genes such as DUSP22,IRF4,EXOC2,HUS1B,LOC285768,FOXQ1,FOXF2 and FOXC1,while another 0.46 Mb deletion was found in the long arm 6q27 region,involving 7 genes such as LOC154449,DLL1,FAM120B,PSMB1,TBP and PDCD2.According to analysis of the results in the patient and literature review,we found that all the patients suffered from neurological or developmental disorders,but external genital anomaly was seen in only two patients,including this patient.Conclusion The different clinical phenotypes in patients with a ring chromosome 6 are closely associated with the location and size of deletion and instability of ring chromosome.