BsaXI/RFLP analysis of initial or selectively reamplified PCR product is unreliable in detecting the V617F mutation in JAK2.

INTRODUCTION: Laboratory testing for the presence of the V617F mutation in JAK2 has taken on great importance in the diagnosis of myeloproliferative disorders. The availability of a facile detection method would bring this testing into greater clinical use. The polymerase chain reaction coupled with restriction fragment length polymorphisms is such a facile method. BsaXI cleaves the normal sequence but does not cleave the sequence leading to the V617F mutation. METHODS: We have examined the use of selective PCR reamplification with BsaXI cleavage to enrich the fraction of V617F and compared the assignment of mutation with an established qPCR method. RESULTS: We found that BsaXI fails to completely cleave normal sequence PCR product, leading to false positivity, particularly at low mutation levels. We also found that first-round standard PCR introduces new mutations in which subsequent reamplification and digestion cannot distinguish from the V617F mutation. CONCLUSION: This combination of problems effectively combines to render selective reamplification and redigestion unsuitable for detecting low fractions of the V617F mutation.

Elective non-instrumented anterior cervical diskectomy and fusion in Ghana: a preliminary report.

BACKGROUND: This study is a retrospective analysis of forty-one consecutive patients who underwent elective single or multilevel anterior cervical diskectomy and fusion (ACDF) in Ghana. All the patients had been followed up for at least six months. METHODS: The medical records of forty-one consecutive cases were analysed retrospectively. The parameters reviewed included patient demographics and presentations, number of fusion levels, complications and clinical outcome. RESULT: Non-instrumented ACDF constituted 22% of all the neurosurgical procedures performed during the study period. A total of 41 patients underwent the procedure. Seventy-eight percent of the patients were male; the mean age of all the patients was 52 years; follow-up was for an average of 21 months. Preoperative assessment revealed that 98% had myelopathy and 2% had radiculopathy only. No patient was operated on for only pain. There were no repeat operations performed. All levels operated on were fused for a total of 67 levels; 37% at one level only and 63% at two levels; no patient was fused or operated on at three levels. Ninety percent of the fusions were at the C4-5 and C5-6 levels. The mean ages of males and females fused at one level only were 48 and 60 years respectively; the difference was statistically significant (P<0.05). For patients fused at two levels; 81% were males and 19% were females, the difference was statistically significant (P<0.05). However, there was no statistical difference between the ages of males and females operated on at two levels (P>0.05). In addition there was no statistical difference between the ages of males operated on at one level or two levels nor was there a difference between the ages of females operated on at one or two levels (P>0.05). The mean preoperative Nurick grade was 2.3 (SD, 1.9); the mean Nurick grade postoperation was 1.3 (SD, 1.3). The difference is significant (P<0.001). There was also a significant relationship between the preoperative and postoperative Nurick grades for males operated on at either one or two levels (P<0.01); however none could be demonstrated for females (P>0.01). The total operative complication rate was 12%; the most common complication was graft/donor site infection (7%). There was no operative or postoperative mortality. Eighty six percent of the patients had an excellent or good clinical outcome as defined by Odom's criteria. Of the 34% who did not have excellent or good clinical outcome, follow up radiologic studies showed excellent graft fusion in all of them. CONCLUSION: The majority of patients undergoing non-instrumented ACDF in Ghana have cervical myelopathy involving two cervical levels. However, a large majority of them have excellent or good clinical results after surgery. The most common complication is graft/donor site infection.