Usher syndrome (USH) is an autosomal recessive hereditary disease,characterized as retinitis pigmentosa and deafness.According to the severity of hearing loss,presence or absence of vestibular dysfunction,Usher syndrome is divided into 3 clinical subtypes..USH1,USH2 and USH3.Due to the genetically heterogeneous,it is important and valuable to find out the gene mutations in USH patients,which will be helpful to prenatal diagnosis,early intervention and gene therapy.Till now,the following 13 USH-related chromosomal loci were reported in the literature:USH1B,USH1C,USH1D (CDH23 gene),USH1F (PCDH15 gene),USH1G (SANS gene),USH1E,USH1H,USH1J and USH1K,USH2A,USH2C,USH2D and USH3 (CLRN1 gene).Ten out of all 13 loci have been located and identified.But more mechanisms should be further investigated,such as the relationship between the locus of gene mutations and clinical symptoms,how the modified protein structures and functions trigger clinical symptoms.

Objective:To investigate the impact of daily step count on glycemic outcomes in community residents with impaired glucose tolerance (IGT).Methods:This was a prospective cohort study, in October 2018, 204 residents who met the criteria of IGT were recruited in the Shijingshan District in Beijing. The subjects were tested for fasting blood glucose, oral glucose tolerance test 2-hour blood glucose (2hBG), glycated hemoglobin A 1c (HbA 1c), lipid profile, liver and kidney function, as well as measurements of height, weight and waist circumference. A dedicated mobile application was used to deliver prediabetes health knowledge monthly. Online guidance was provided to answer questions and daily step count was collected using the application. Three years later, a follow-up was conducted to assess the participants′ glycemic outcomes and other indexes, and a total of 142 participants completed the follow-up review. According to daily step count, the subjects were categorized into high step count group (42 cases,>7 000 steps daily), moderate step count group (54 cases, 5 000-7 000 steps daily), and low step count group (46 cases,<5 000 steps daily). Subjects were categorized into diabetes group (30 cases), prediabetes group (77 cases) and normal glucose tolerance group (35 cases) with glycemic outcomes. Independent sample t test was used to compare the differences in blood glucose, blood lipids, and step counts between the two groups. Kruskal-Wallis H test or one-way ANOVA was used to compare the differences in blood glucose, blood lipids, and step counts between multiple groups. The χ2 test was used to compare the differences in glycemic outcomes between multiple groups. Multivariate logistic regression analysis was used to assess the impact of daily step counts and body mass index on glycemic outcomes. Linear regression analysis was used to evaluate the relationship between daily step counts and 2 h BG. Results:A total of 142 participants completed the 3-year follow-up, including 43 males and 99 females, with a mean age of (60.15±5.67) years. At baseline, males had significantly higher body mass index, waist circumference, and fasting blood glucose when compared to those in females [(26.97±2.43) vs (24.89±2.93) kg/m 2, (92.68±7.75) vs (83.83±8.60) cm, (5.83±0.61) vs (5.62±0.52) mmol/L], the total cholesterol and HDL-C were also significantly lower in males than those in females [(5.10±1.16) vs (5.55±0.95) mmol/L, (1.35±0.34) vs (1.56±0.35) mmol/L] (all P<0.05). After 3-year follow-up, 21.1% (30/142) of IGT participants progressed to diabetes, with an annual conversion rate of approximately 7%. The normal glucose tolerance group showed significantly higher daily step counts when compared with the prediabetes and diabetes groups [(7 886±2 867) vs (5 981±2 655) vs (4 117±2 674) steps] ( H=31.778, P<0.001). Individuals with higher daily step counts exhibited lower body mass index, 2 h BG, and HbA 1c level when compared with those in the ones with moderate and low step counts [(24.26±3.09) vs (25.44±3.38) vs (26.26±3.59) kg/m 2, (7.50±1.71) vs (9.15±3.30) vs (11.19±3.84) mmol/L, 5.97%±0.46% vs 6.14%±0.99% vs 6.40%±0.96%] (all P<0.05). Higher step count was positively correlated with the reversal of prediabetes to normal blood glucose levels (moderate step count, OR=0.297, 95% CI: 0.109-0.804; low step count, OR=0.055, 95% CI: 0.010-0.287), lower daily step count correlated positively with prediabetes progressing to diabetes ( OR=4.857, 95% CI: 1.140-20.689) (all P<0.05). For every additional 1 000 steps per day, the 2 h BG decreased by 0.5 mmol/L. Conclusion:As daily step count increases, the glucose metabolism improves in IGT community residents. Higher daily step count is associated with reversal of IGT to normal glucose tolerance, while lower daily step count may be associated with the progression of IGT to diabetes.