Zlotina Anna, Kiselev Artem, Sergushichev Alexey, Parmon Elena, Kostareva Anna
Almazov National Medical Research Centre, Saint Petersburg, Russia.
ITMO University, Saint Petersburg, Russia.
Front Genet. 2018 Jun 15;9:209. doi: 10.3389/fgene.2018.00209. eCollection 2018.
"Heart-hand" type syndromes represent a group of rare congenital conditions that combine cardiac pathology (structural defect or arrhythmic disorder) and limb abnormality. Significant clinical variability and genetic heterogeneity typical for such syndromes complicate correct diagnosis, prognosis, and appropriate genetic counseling of the affected families. By now, only single genes have been unambiguously determined as a genetic cause of heart-hand syndromes and phenotypically similar conditions. In the present study, we report on a 25-year-old Russian female patient with a clinical picture resembling ulnar-mammary syndrome (UMS). Principal clinical manifestations included heart septal fibrosis and non-sustained left ventricular tachycardia combined with fifth finger camptodactyly, hypoplastic breast, abnormal teeth, and mental retardation. Target Sanger sequencing and array-based comparative genome hybridization confirmed the lack of pathogenic mutations and large-scale deletions in (12q24.21), the only gene known to be associated with UMS cases to date. Based on the results of whole-exome sequencing, 14 potential candidate variants were identified. Among them, a novel missense variant in gene (exon 1, c.173C > T, p.A58V), encoding intermediate filament protein synemin was characterized. Until the present, no association between mutations and congenital clinical syndromes has been reported. At the same time, taking into account synemin tissue-specific expression profiles and available data on abnormal knock-out mice phenotypes, we propose as a candidate gene contributing to the UMS-like phenotype. Further comprehensive functional studies are required to evaluate possible involvement of in genesis of complex heart-limb pathology.
“心-手”型综合征是一组罕见的先天性疾病,其合并了心脏病变(结构缺陷或心律失常)和肢体异常。这类综合征典型的显著临床变异性和基因异质性使得对受影响家庭的正确诊断、预后评估及适当的遗传咨询变得复杂。到目前为止,只有单个基因已被明确确定为心-手综合征及表型相似病症的遗传病因。在本研究中,我们报告了一名25岁的俄罗斯女性患者,其临床表现类似于尺骨-乳腺综合征(UMS)。主要临床表现包括心脏间隔纤维化和非持续性左室心动过速,同时伴有第五指屈曲挛缩、乳腺发育不全、牙齿异常和智力发育迟缓。靶向桑格测序和基于阵列的比较基因组杂交证实,在迄今已知与UMS病例相关的唯一基因(12q24.21)中不存在致病突变和大规模缺失。基于全外显子组测序结果,鉴定出14个潜在的候选变异。其中,对编码中间丝蛋白丝联蛋白的基因(外显子1,c.173C>T,p.A58V)中的一个新型错义变异进行了特征分析。迄今为止,尚未报道丝联蛋白突变与先天性临床综合征之间的关联。同时,考虑到丝联蛋白的组织特异性表达谱以及关于异常基因敲除小鼠表型的现有数据,我们提出丝联蛋白作为导致类似UMS表型的候选基因。需要进一步进行全面的功能研究,以评估丝联蛋白在复杂的心-肢病理发生过程中可能的参与情况。