Yang Yaya, Wang Yidan, Gao Jian
Reproductive Genetics Department, Hebei General Hospital, Shijiazhuang, Hebei, China.
J Cell Mol Med. 2024 Dec;28(23):e70275. doi: 10.1111/jcmm.70275.
It is very difficult to identify the genetic variation of haemophilia A. We examined a case report from a sizable, uncommon haemophilia family, analysing the application of DHPLC in the diagnosis of haemophilia A. The comprehensive clinical data and laboratory assessments of the proband within the family were meticulously compiled. Subsequent to this, tests were conducted to evaluate the activated partial prothrombin time (APTT) and the clotting activity of coagulation factor VIII (F VIII: C). Polymerase chain reaction (PCR) techniques were employed to identify any inversions within the F8 gene's introns 22 and 1. Thereafter, direct sequencing methodology was utilised to sequence all exons of the F8 gene. To analyse the copy number variations across all exons of the F8 gene, a multiple PCR combined with denaturing high-performance liquid chromatography (DHPLC) approach was adopted. In addition, specific pathogenic mutations predisposing to progenitor cell disorders were screened in family members. The APTT of the proband was 60 s. F VIII: C is < 1%. It was found that the progenitor F8 gene exon 14 had a 226 bp insertion sequence, which was of unknown origin and was a pathogenic mutation. The analysis combined with this family situation is consistent with the expectation. The mutation was used as the detection target to complete the prenatal diagnosis. The pathogenic mutation found in this family is a rare large fragment insertion mutation. It is necessary to combine multiple experimental methods to improve the success rate of genetic diagnosis of haemophilia A.
很难鉴定甲型血友病的基因变异。我们研究了一个来自规模较大、较为罕见的血友病家族的病例报告，分析了变性高效液相色谱法（DHPLC）在甲型血友病诊断中的应用。该家族中先证者的全面临床资料和实验室评估被精心整理。在此之后，进行了活化部分凝血活酶时间（APTT）和凝血因子VIII（F VIII：C）凝血活性的检测。采用聚合酶链反应（PCR）技术鉴定F8基因内含子22和1内的任何倒位。此后，利用直接测序方法对F8基因的所有外显子进行测序。为分析F8基因所有外显子的拷贝数变异，采用了多重PCR结合变性高效液相色谱（DHPLC）的方法。此外，对家族成员中易患祖细胞疾病的特定致病突变进行了筛查。先证者的APTT为60秒。F VIII：C <1%。发现先证者F8基因外显子14有一个226 bp的插入序列，其来源不明，是一个致病突变。结合该家族情况的分析与预期相符。将该突变用作检测靶点完成了产前诊断。该家族中发现的致病突变是一种罕见的大片段插入突变。有必要结合多种实验方法提高甲型血友病基因诊断的成功率。
