OBJECTIVE: To establish a newborn screening system for Duchenne muscular dystrophy (DMD) through assessment of MM isoenzyme of creatine kinase (CK-MM) activity. METHODS: The CK-MM level was detected using dry blood spot filter paper from 10 252 male newborns. The results were grouped based on their gestational age, sampling time and intervals between the experiments. The threshold value for CK-MM necessitating genetic testing was determined. Next-generation sequencing (NGS) was carried out for those with a CK-MM value over the threshold, and the result was verified by multiplex ligation-dependent probe amplification (MLPA). RESULTS: Based on the result of non-parametric rank sum test, the median CK-MM concentration has increased with the gestational age, and was inversely correlated with the age of the newborns among unaffected specimens. CK-MM on dry blood spot filter paper can be stable for 14 days at 2-8℃. Statistical analysis of CK-MM value of the 10 252 neonates suggested that the threshold may be set as 700 ng/mL. Exonic deletions were found in 2 confirmed cases, whose CK-MM level was greater than 2000 ng/mL. CONCLUSION Detection of CK-MM in dry blood spot filter paper has provided an effective method for newborn screening of DMD. This simple and inexpensive method can be used for large-scale screening, which is of great value to the early intervention and treatment of the disease.
Dystrophin/genetics* ; Exons ; Humans ; Infant, Newborn ; Male ; Multiplex Polymerase Chain Reaction ; Muscular Dystrophy, Duchenne/genetics* ; Neonatal Screening

Objective: To explore the effect of reducing complication in branched spongiosum repair for hypospadias Duckett surgery. Methods: Retrospective analysis was performed for the clinical data of 140 surgical infants with hypospadias Duckett surgery from January 2016 to April 2018. According to different covering materials on newly formed urethra, the experimental group (68 cases) cut dysplasia, branched spongiosum and lateral Buck′s fascia from tunica albuginea to coronary groove and then sutured over newly formed urethra, and the control group (72 cases) used Dartos fascia or subcutaneous fascia. The operative age, penile curvature, length of urethral defect, operation time, added value of coronary groove before and after operation, maximum urinary flow rate and complication rate of postoperative follow-up were compared between the two groups, and the therapeutic effect was analyzed. Results: There was no statistically significant difference between two groups in operating time[(135±49)min vs.(135±45)min, P=0.580] and the value added of coronary sulcus[(0.1±0.2)cm vs.(0.1±0.1)cm, P=0.167]. In experimental group, there were 8 cases of urethra percutaneous fistula (11.8%) (coronary groove fistula in 3 cases, 4.4%)and 6 cases of urethral stenosis (8.8%) without urethral dehiscence. In control group, there were 18 cases of urethra percutaneous fistula (25.0%)(coronary groove fistula in 11 cases, 15.3%), 10 cases of urethral stenosis (13.9%), and 2 cases of urethral dehiscence (2.8%). The incidence of postoperative urinary fistula and total complications in experimental group was lower than that in the control group, and the difference was statistically significant (P<0.05), while the incidence of urethral stenosis was not statistically different between two groups (P>0.05). The maximum urine flow rate of experimental group at 6 months after surgery was significantly higher than control group[(9.5±3.8)ml/s vs.(6.8±2.8)ml/s], and the difference was statistically significant (P<0.001). Conclusions Urethral cavernosum reconstruction can significantly reduce the incidence of postoperative coronary groove fistula of hypospadias Duckett surgery and improve the postoperative urine flow rate.