X连锁迟发性脊柱骨骺发育不良快速基因诊断方法的研究

Study on rapid diagnosis of spondyloepiphyseal dysplasia tarda family

目的探讨建立X连锁迟发性脊柱骨骺发育不良(SEDT)快速基因诊断的方法。方法发现一个4代68人累及8例患者的SEDT大家系,呈X连锁隐性遗传。在应用PCR和DNA测序方法对SEDL进行基因突变分析后,提取外周血淋巴细胞RNA,应用RT-PCR扩增cDNA直接测序,建立快速基因诊断方法。结果RT-PCR结果显示,家系8例患者均为SEDL基因外显子6插入突变(c.370-371ins A,),并发现1例无症状患儿携带相同突变(症状发生前),6例女性携带者为杂合突变,家系其他成员和正常对照中均未见该插入突变。结沦RT-PCR检测扩增SEDL基因cDNA直接测序是一种快速基因诊断的方法。

Objective： To develop a rapid diagnostic method for spondyloepiphyseal dysplasia tarda （SEDT）. Methods： A four- generation SEDT family with 8 affected individuals was reported. The inheritance mode of the pedigree was X - linked recessive. On the basis of PCR and DNA sequencing of SEDL gene, total RNA was extracted from leukomonocytes of peripheral blood and RT - PCR was carried out to amply the coding region of SEDL directly. Results ： RT - PCR and direct sequencing results revealed that there was a single nucleotide of A insertion （c. 370 -371 ins A ） in exon 6 of SEDL gene in all 8 patients. Also a presymptomatie persons car- ried the same mutation and the heterozygous mutation was identified in 6 female carriers. But 55 unaffected relatives and the 50 controls （unrelated healthy subjects, 25 males and 25 females） were not found. Conclusion： RT -PCR and sequencing of cDNA is useful in rapid molecular diagnosis for SEDT.