Development of a low-cost and accurate carrier screening method for spinal muscular atrophy in developing countries.

Heterozygous carriers of the survival of motor neuron 1 (SMN1) gene deletion in parents account for approximately 95% of neonatal spinal muscular atrophy cases. Given the severity of the disease, professional organizations have recommended periconceptional spinal muscular atrophy carrier screening to all couples, regardless of race or ethnicity. However, the prevalence of screening activities in mainland China remains suboptimal, mainly attributed to the limitations of the existing carrier screening methods. Herein, we aimed to develop a low-cost, accessible, and accurate carrier screening method based on duplex droplet digital PCR (ddPCR), to cover a wider population in developing countries, including China. The receiver operating characteristic curve was used to determine the cut-off value of SMN1 copy numbers. Performance validation was conducted for linearity, precision, and accuracy. In total, 482 cases were considered to validate the concordance between the developed ddPCR assay and multiplex ligation-dependent probe amplification. Linear correlations were excellent between the expected concentration of the reference gene and the observed values (R2 > 0.99). Both the intra- and inter-assay precision of our ddPCR assays were less than 6.0%. The multiplex ligation-dependent probe amplification and ddPCR results were consistent in 480 of the 482 cases (99.6%). Two cases with multiplex ligation-dependent probe amplification, suggestive of two copies of SMN1 exon 7, were classified into three copies by ddPCR analysis. The overall correct classification of the samples included in our ddPCR assay was 100%. This study demonstrates that an appropriate cut-off value is an important prerequisite for establishing a semi-quantitative method to determine the SMN1 copy numbers. Compared to conventional methods, our ddPCR assay is low-cost, highly accurate, and has full potential for application in population spinal muscular atrophy carriers screening.

Predictor assessment of complete miscarriage after medical treatment for early pregnancy loss in women with previous cesarean section.

This study aimed to evaluate clinical predictors associated with complete miscarriage after medical treatment for early pregnancy loss (EPL) in women with previous cesarean section. Patients with retained uterine content after expulsion followed by administration of mifepristone and misoprostol were included if they chose continued medical treatment rather than surgical intervention. Clinical characteristics including maternal age, gravidity, parity, history of previous cesarean section and ultrasound findings regarding average diameter of the gestational sac, uterine position, width, and blood flow signal of the residual uterine content after expulsion of the gestational sac were included in the analysis to determine predictors of complete miscarriage. A recursive partitioning analysis (RPA) was used to divide the patients into probability groups and assess their probability of complete miscarriage. A total of 89 patients were analyzed. The complete miscarriage rate was 58.43% overall. Multivariable logistic regression analysis showed that the width and blood flow signal of the residual after expulsion were both independent predictors for complete miscarriage (all P < .05). Patients were divided into high-probability (no blood flow signal, width of residual <1 cm), intermediate-probability (no blood flow signal, width of residual ≥1 cm; blood flow signal, width of residual <1 cm), and low-probability (blood flow signal, width of residual ≥ 1 cm) groups by RPA according to these 2 factors. The incidences of complete miscarriage were 88.24%, 67.57%, and 34.29%, respectively, P < .001). Surgical evacuation may be avoided in patients without ultrasonic blood flow of the uterine residual and width of the residual <1 cm. More active treatment could be recommended for patients with ultrasonic blood flow of the uterine residual and width of the residual ≥ 1 cm. Clinicians and patients should be aware of these differences when proceeding with medical treatment for EPL patients with previous cesarean section.

Score for the Overall Survival Probability of Patients With First-Diagnosed Distantly Metastatic Cervical Cancer: A Novel Nomogram-Based Risk Assessment System.

Background: Metastatic cervical cancer (mCEC) is the end stage of cervical cancer. This study aimed to establish and validate a nomogram to predict the overall survival (OS) of mCEC patients. Methods: We investigated the Surveillance, Epidemiology, and End Results (SEER) database for mCEC patients diagnosed between 2010 and 2014. Univariate and multivariable Cox analyses was performed to select the clinically important predictors of OS when developing the nomogram. The performance of nomogram was validated with Harrell's concordance index (C-index), calibration curves, receiver operating characteristic curve (ROC), and decision curve analysis (DCA). Results: One thousand two hundred and fifty-two mCEC patients were included and were divided into training (n = 880) and independent validation (n = 372) cohorts. Age, race, pathological type, histology grade, radiotherapy, and chemotherapy were independent predictors of OS and used to develop the nomogram for predicting 1- and 3-year OS. This nomogram had a C-index of 0.753 (95% confidence interval [CI]: 0.780-0.726) and 0.751 (95% CI: 0.794-0.708) in the training and the validation cohorts, respectively. Internal and external calibration curves indicated satisfactory agreement between nomogram prediction and actual survival, and DCA indicated its clinical usefulness. Furthermore, a risk stratification system was established that was able to accurately stratify mCEC patients into three risk subgroups with significantly different prognosis. Conclusions: We constructed the first nomogram and corresponding risk classification system to predict the OS of mCEC patients. These tools showed satisfactory accuracy, and clinical utility, and could aid in patient counseling and individualized clinical decision-making.