RESUMO
Rabbits are mainly bred for human consumption and medical research. However, it has been recently showed that several rabbit breeds are also kept as pets for human leisure. The Netherlands dwarf rabbit is currently in the immense interest of many Vietnamese customers due to its personality and miniature stature. However, 12.1 kb deletion from position 44,709,089 to 44,721,236 bp in the high mobility AT-hook 2 (HMGA2) gene on chromosome 4 was identified as the structural variant causing dwarfism and altered craniofacial development in this breed. It has been documented that HMGA2 plays an important role in regulating growth and individuals with genotype HMGA2 del/del are fatal several days after birth. Despite the economically high value of the Netherlands dwarf rabbit, there has been no study on the genetic survey of lethal alleles in this breed in Vietnam. The aim of this study is to develop a fast and reliable method to screen the frequency of lethal alleles of HMGA2 in the South of Vietnam. Rabbit saliva was collected, and DNA extraction was followed. Multiplex polymerase chain reaction (PCR) with three primers was optimized and performed to detect the presence of 12.1 kb deletion within the HMGA2 sequence. Our data showed that the 12.1 kb deletion in the Netherlands dwarf rabbit population was detected by our optimized multiplex PCR. In 100 rabbit animals, 34 and 16 individuals were homozygous wild type (+/+) and homozygous mutant (del/del), respectively, while 50 rabbits were heterozygous. The frequency of HMGA2 lethal allele carrier was 66% (66/100 individuals). Our results indicated that we successfully developed a fast, accurate multiplex PCR to detect carrier individuals. Verification of the genotypes was followed by sequencing. We recommend implementing our multiplex PCR procedure in genetic selection for carrier and homozygous wild-type animals in the mating scheme to prevent the lethality of the rabbit offspring. Additionally, awareness should be raised among rabbit breeders to monitor the genetic makeup of the Netherlands dwarf rabbit populations. However, due to the limitation of the sample size, more samples should be taken in future studies to obtain the genetic frequency of the HMGA2 lethal allele more accurately.
RESUMO
Objectives: A simple and efficient tool for evaluating ovarian tumors in general hospitals where radiologists without experience in gynecological ultrasound is necessary. This study aims to evaluate the diagnostic performance of IOTA simple rules in initial classification of ovarian tumors by non-experienced examiners who have received simple training. Materials and method: A prospective single-center study was conducted at Hanoi Obstetrics and Gynecology Hospital. Three resident gynecologists trained themselves for two weeks and then received hands-on practice under the supervision of experts for another two weeks. The examiners performed ultrasound on 424 eligible women scheduled for surgery for ovarian tumors and classified the tumors based on IOTA simple rules. The postoperative pathology of ovarian tumors was used as the gold standard. Results: 90.8 % (385/424) of the tumors were benign. Simple rules were applicable in 399/424 (94.1 %) tumors, with a sensitivity of 84.8 % (95 % CI, 70.2-94.3), specificity of 98.9 % (95 % CI, 97.5-99.7), positive predictive value of 87.5 % (95 % CI, 73.3-95.9), and negative predictive value of 98.6 % (95 % CI, 97.1-99.5). The sensitivity of IOTA simple rules was higher in postmenopausal women (91.7 % vs. 81.0 %), while the specificity was higher in premenopausal women (99.4 % vs. 95.8 %). Accuracy was 100 % in all ten pregnant women were assessed using these rules. Conclusion: In conclusion, in the hands of non-expert examiners who were trained thoroughly, IOTA simple rules are a simple and efficient tool for clinical practice in centers where expert radiologists in gynecology are not always available. The training program is simple and could be applied widely in other clinical centers. Further studies are necessary to evaluate the effectiveness of the IOTA simple rules in assessing ovarian tumors among pregnant women.