Photoactivatable Cre knock-in mice for spatiotemporal control of genetic engineering in vivo.

Although the Cre-loxP recombination system has been extensively used to analyze gene function in vivo, spatiotemporal control of Cre activity is a critical limitation for easy and precise recombination. Here, we established photoactivatable-Cre (PA-Cre) knock-in (KI) mice at a safe harbor locus for the spatial and temporal regulation of Cre recombinase activity. The mice showed whole-body Cre recombination activity following light exposure for only 1 h. Almost no leaks of Cre recombination activity were detected in the KI mice under natural light conditions. Spot irradiation could induce locus-specific recombination noninvasively, enabling us to compare phenotypes on the left and right sides in the same mouse. Furthermore, long-term irradiation using an implanted wireless LED substantially improved Cre recombination activity, especially in the brain. These results demonstrate that PA-Cre KI mice can facilitate the spatiotemporal control of genetic engineering and provide a useful resource to elucidate gene function in vivo with Cre-loxP.

Prevalence of thromboembolic events and status of prophylactic anticoagulant therapy in hospitalized patients with COVID-19 in Japan.

INTRODUCTION: One of the most prominent and concerning complications associated with coronavirus disease 2019 (COVID-19) is venous and arterial thromboembolisms. The aim of the present study was to delineate the prevalence of thromboembolic events and the current status of prophylactic anticoagulation therapy in patients with COVID-19 in Japan. METHODS: Between February 1 and August 31, 2020, we performed a dual-center, retrospective cohort study based on data obtained from the medical charts of COVID-19 patients admitted to healthcare facilities in Japan. The primary outcome was any thromboembolic event including pulmonary embolism (PE), deep vein thrombosis (DVT), myocardial infarction, ischemic stroke and other systemic thromboemboli. RESULTS: During the study period, we extracted 628 consecutive patients admitted for COVID-19. Prophylactic anticoagulant therapy was administered in 63 (10%) patients of whom 20 (31.7%) were admitted to the intensive care unit (ICU). Thromboembolic events occurred in 18 (2.9%) patients (14.3% of patients in ICU and 2.2% of patients in the general wards). DVT were detected in 13 (2.1%) patients, PE in 11 (1.8%), and both DVT and PE in 6 (0.96%) patients. An increasing prevalence in thromboembolic events was noted with progressive clinical severity. Overall in-hospital mortality was 4.8%. CONCLUSIONS: Prophylactic anticoagulation therapy was administered in only 10% of all hospitalized COVID-19 patients. The prevalence of any thromboembolic events was 2.9% in COVID-19 patients with most events occurring in severe and critical patients. Therefore, prophylactic anticoagulation therapy may be warranted in severe and critical patients but in asymptomatic to moderate patients the practice remains controversial.

A comparison on the percentage of polymerase chain reaction positivity for SARS-CoV-2 between Public Health Center referrals and direct walk-in patients: A single center retrospective analysis in Tokyo.

INTRODUCTION: The Public Health Center (PHC)-known as hokenjo in Japan-assume a crucial role in disease control. Coronavirus disease 2019 (COVID-19) is one of many designated infectious diseases monitored by the agency. During the present pandemic, patients who suspected COVID-19 were instructed to call the Coronavirus Consultation Center in the PHC prior to visiting the hospital. The aim of this study was to elucidate the differences in polymerase chain reaction (PCR) positivity between PHC referrals and direct walk-in patients. METHODS: The present was a single-center, retrospective cohort study conducted at the Tokyo Metropolitan Hospital from March to September, 2020. Patients who received a PCR test for SARS-CoV-2 were included and categorized into the PHC referral or direct walk-in groups. The outcomes included the total number of patients undergoing PCR tests and the percentage of PCR positivity in each group. RESULTS: We identified 1680 patients (781 PHC referred and 899 direct walk-in groups). The percentage of PCR positivity did not significantly differ between the PHC referral and direct walk-in groups during the first wave (30.5% vs. 29.2%; p = 0.78). PCR positivity was significantly higher in the PHC referral group than the direct walk-in group during the second wave (30.1% vs. 23.1%; p = 0.051) and entire study period (30.2% vs. 24.7%; p = 0.011). CONCLUSIONS: Despite health authority recommendations, the number of direct walk-in patients were higher than PHC referral patients. The percentage of PCR positivity was significantly higher in the PHC referral group than in the direct walk-in group.

Creutzfeldt-Jakob disease with Alzheimer pathology, presenting with status epilepticus following repeated partial seizures: a case report and literature review.

BACKGROUND: Creutzfeldt-Jakob disease (CJD) is a fatal neurodegenerative disease. Common first symptoms are dementia, cerebellar ataxia, visual disturbance, and psychiatric symptoms. Seizure as the first symptom of CJD is a very rare finding. CASE PRESENTATION: We experienced an elderly woman who presented initially with status epilepticus following repeated partial seizures in the course of Alzheimer disease (AD) dementia. Anti-convulsive therapy had no effect. Autopsy revealed definite CJD with AD pathology. COCLUSIONS: This is the first reported CJD case presenting with status epilepticus in the course of AD dementia.

[RISK OF TUBERCULOSIS INFECTION AND DISEASE AMONG JAPANESE FEMALE NURSES AND MALE DOCTORS IN RECENT YEARS].

[Objectives and Materials] Based on the tuber- culosis (TB) surveillance database, the incidence rates of TB infection and active disease among healthcare workers were observed for female nurses and male doctors in 2010 in comparison with those of the general population. [Results] The relative risk (RR) of active TB among female nurses aged 20-69 years was 4.86 (95% confidence interval: 4.31-5.45) for 2010, which has increased from 2.30 observed in 1987-1997. The RR was highest for nurses aged 20-29 years at 8.84 and declined with age until 3.60 for those aged 50-59 years that was still significantly higher than 1. For male doctors the RR was significantly higher than 1 only for those aged 39 years or younger. The rates of those who were -indicated for treatment of latent TB infection (LTBI) were clearly higher among healthcare workers; for female nurses the RR was 32.7 (95% CI: 30.5-35.0), ranging from the highest level of 62.8 among those aged 20-29 years down to 11.6 for those aged 60-69 years. For male doctors also, the RR was high at 9.7 (7.9- 11.7) for 20-69 years, ranging from 14.5 for those aged 20- 29 years down to 5.3 for those aged 60-69 years. [Discussion] TB cases of nurses and doctors were more likely to be detected by the active case finding measures such as periodic screening and contact investigations than cases in the general population, which indicates the current effort of addressing the occupational exposure in the healthcare set- tings. The high level of risk of TB disease as Iwell as LTBI among healthcare professions and its possibly increasing trend as. seen in female nurses warrants further strengthening of monitoring of the problem and overall countermeasures in their workplaces.

Factors Influencing Time Lag Between Initial Parental Concern and First Visit to Child Psychiatric Services Among ADHD Children in Japan.

The aim of this study was to examine the factors associated with a time lag between initial parental concern about ADHD symptoms and the first visit to a hospital in Japan that offers child psychiatric services. We investigated the demographic characteristic, symptoms, diagnosis, and healthcare system factors including duration between initial parental concern about symptoms and the first visit to a hospital (N = 387). The mean time lag between initial parental concern and the first visit to a hospital was 2.6 years. Risk factors for a longer time lag include the young age of a child, behavioral problems of the child, lower maternal education, difficulty in determining appropriate medical institution, referral route, and the distance from home to the hospital. A more established connection between a hospital with child psychiatric services and other health institutions is recommended for earlier referral to an appropriate hospital.

Genome editing using type I-E CRISPR-Cas3 in mice and rat zygotes.

The type I CRISPR system has recently emerged as a promising tool, especially for large-scale genomic modification, but its application to generate model animals by editing zygotes had not been established. In this study, we demonstrate genome editing in zygotes using the type I-E CRISPR-Cas3 system, which efficiently generates deletions of several thousand base pairs at targeted loci in mice with 40%-70% editing efficiency without off-target mutations. To overcome the difficulties associated with detecting the variable deletions, we used a newly long-read sequencing-based multiplex genotyping approach. Demonstrating remarkable versatility, our Cas3-based technique was successfully extended to rats as well as mice, even by zygote electroporation methods. Knockin for SNP exchange and genomic replacement with a donor plasmid were also achieved in mice. This pioneering work with the type I CRISPR zygote editing system offers increased flexibility and broader applications in genetic engineering across different species.

Pseudoirreversible inhibition elicits persistent efficacy of a sphingosine 1-phosphate receptor 1 antagonist.

Sphingosine 1-phosphate receptor 1 (S1PR1), a G protein-coupled receptor, is required for lymphocyte trafficking, and is a promising therapeutic target in inflammatory diseases. Here, we synthesize a competitive S1PR1 antagonist, KSI-6666, that effectively suppresses pathogenic inflammation. Metadynamics simulations suggest that the interaction of KSI-6666 with a methionine residue Met124 in the ligand-binding pocket of S1PR1 may inhibit the dissociation of KSI-6666 from S1PR1. Consistently, in vitro functional and mutational analyses reveal that KSI-6666 causes pseudoirreversible inhibition of S1PR1, dependent on the Met124 of the protein and substituents on the distal benzene ring of KSI-6666. Moreover, in vivo study suggests that this pseudoirreversible inhibition is responsible for the persistent activity of KSI-6666.

[Clinical experience of primaquine use for treatment of vivax and ovale malaria in Japanese travelers].

Primaquine phosphate has been used to prevent relapse as a radical cure after the acute-phase treatment of vivax and ovale malaria however. Many vivax malaria relapses have been reported following a standard dose of primaquine (15 mg/day for 14 days). A higher dose of primaquine (30 mg/day for 14 days) decreases the relapse rate, and the concomitant risk of gastrointestinal side effects tends to disappear when the drug is administered with food. G6PD deficiency is rare in the Japanese population. Although the relapsed phenomenon is reported globally, the higher dose of primaquine is currently recommended in Japan only for those returning from Southeast Asia or Papua New Guinea. Cases of 18 Japanese, including 13 vivax malaria and 5 ovale malaria, prescribed primaquine at a referral center in Japan, were analyzed retrospectively from 2007-2011. Data on diagnosis, treatment, and outcome were extracted from medical records. Of the 18, 10 with vivax malaria were administered the higher dose of primaquine. We found that only one suffered relapse-a vivax malarial case returning from Brazil and treated with the standard dose of primaquine. No ovale malarial case suffered relapse. None, including the 10 prescribed the higher primaquine dose, experienced any adverse side effects. Based on our findings, we recommend a higher dose of primaquine be used to prevent relapse when treating Japanese suffering from vivax malaria.

[Clinical features of girls with Asperger disorders].

OBJECTIVES: Symptoms of Asperger disorder (AD) in girls are often different from those in boys. In this study, the characteristics of girls with AD were examined. METHODS: We retrospectively examined the records of 63 boys and 33 girls with AD. We evaluated the age, main problems, complications, and the Wechsler Intelligence Scale for Children (3rd Ed) scores. RESULTS: About 73% of girls were diagnosed with AD between 10 and 15 years of age, and they had physical complications or problems in the autonomic nervous system. Girls scored significantly lower in Mathematics score, and Block Design score than boys. CONCLUSIONS: The results suggest that there are differences in the AD symptoms exhibited by boys and girls. Further research is required to clarify the behavioral, neurological, and genetic links to these gender differences. In order to prevent secondary complications, it is necessary to establish specific diagnostic criteria for girls with AD.

Computerized surveillance system of tuberculosis in Japan: its evolution, achievement and challenges.

The nationwide computerized tuberculosis (TB) surveillance system was revised in 2007. It was developed to be user-friendly and to allow the evaluation of current TB problems and control issues in Japan. All public health centers in Japan (518 as of April 2007) have system terminals connected to a central computer, and the data entered at these terminals are sent to the online central computer excluding personal identification data. All the figures and tables in this paper were created using the annual report database which are compiled from this system. The revision in 2007 added many new functions to the system, such as a function for automatically sending data upon transfer. The monitoring information for assisting case management of TB patients by the DOTS was also enhanced. The algorithm for classifying treatment outcomes automatically based on data entered regarding cancellations from registration, bacteriological results and drug usage each month was revised. The proportion of "Failed" and "Defaulted" combined was 4.6% among new sputum smear positive pulmonary TB patients newly registered in 2009, while "Died" accounted for as high as 19.3%, due largely to a high percentage of the elderly. A new system for contact examination management is provided as a subsystem. Feedback of data analyses has been strengthened by various methods. This TB surveillance system is indispensable for implementing the evidence-based TB control program in Japan. An important role of the Research Institute of Tuberculosis is to support the planning and execution of TB control with provision of useful epidemiological information from the system.

A high-quality severe combined immunodeficiency (SCID) rat bioresource.

Immunodeficient animals are valuable models for the engraftment of exogenous tissues; they are widely used in many fields, including the creation of humanized animal models, as well as regenerative medicine and oncology. Compared with mice, laboratory rats have a larger body size and can more easily undergo transplantation of various tissues and organs. Considering the absence of high-quality resources of immunodeficient rats, we used the CRISPR/Cas9 genome editing system to knock out the interleukin-2 receptor gamma chain gene (Il2rg) in F344/Jcl rats-alone or together with recombination activating gene 2 (Rag2)-to create a high-quality bioresource that researchers can freely use: severe combined immunodeficiency (SCID) rats. We selected one founder rat with frame-shift mutations in both Il2rg (5-bp del) and Rag2 ([1-bp del+2-bp ins]/[7-bp del+2-bp ins]), then conducted mating to establish a line of immunodeficient rats. The immunodeficiency phenotype was preliminarily confirmed by the presence of severe thymic hypoplasia in Il2rg-single knockout (sKO) and Il2rg/Rag2-double knockout (dKO) rats. Assessment of blood cell counts in peripheral blood showed that the white blood cell count was significantly decreased in sKO and dKO rats, while the red blood cell count was unaffected. The decrease in white blood cell count was mainly caused by a decrease in lymphocytes. Furthermore, analyses of lymphocyte populations via flow cytometry showed that the numbers of B cells (CD3- CD45+) and natural killer cells (CD3- CD161+) were markedly reduced in both knockout rats. In contrast, T cells were markedly reduced but showed slightly different results between sKO and dKO rats. Notably, our immunodeficient rats do not exhibit growth retardation or gametogenesis defects. This high-quality SCID rat resource is now managed by the National BioResource Project in Japan. Our SCID rat model has been used in various research fields, demonstrating its importance as a bioresource.

Dynamic mechanisms of CRISPR interference by Escherichia coli CRISPR-Cas3.

Type I CRISPR-Cas3 uses an RNA-guided multi Cas-protein complex, Cascade, which detects and degrades foreign nucleic acids via the helicase-nuclease Cas3 protein. Despite many studies using cryoEM and smFRET, the precise mechanism of Cas3-mediated cleavage and degradation of target DNA remains elusive. Here we reconstitute the CRISPR-Cas3 system in vitro to show how the Escherichia coli Cas3 (EcoCas3) with EcoCascade exhibits collateral non-specific single-stranded DNA (ssDNA) cleavage and target specific DNA degradation. Partial binding of EcoCascade to target DNA with tolerated mismatches within the spacer sequence, but not the PAM, elicits collateral ssDNA cleavage activity of recruited EcoCas3. Conversely, stable binding with complete R-loop formation drives EcoCas3 to nick the non-target strand (NTS) in the bound DNA. Helicase-dependent unwinding then combines with trans ssDNA cleavage of the target strand and repetitive cis cleavage of the NTS to degrade the target double-stranded DNA (dsDNA) substrate. High-speed atomic force microscopy demonstrates that EcoCas3 bound to EcoCascade repeatedly reels and releases the target DNA, followed by target fragmentation. Together, these results provide a revised model for collateral ssDNA cleavage and target dsDNA degradation by CRISPR-Cas3, furthering understanding of type I CRISPR priming and interference and informing future genome editing tools.

CRISPR-Cas3-based diagnostics for SARS-CoV-2 and influenza virus.

CRISPR-based diagnostics (CRISPR-dx), including the Cas12-based DETECTR and Cas13-based SHERLOCK Class 2 CRISPRs, have been used to detect the presence of DNA or RNA from pathogens, such as the 2009 pandemic influenza virus A (IAV) and the 2019 novel coronavirus SARS-CoV-2. Here, we describe the collateral single-stranded DNA cleavage with Class 1 type I CRISPR-Cas3 and highlight its potential for development as a Cas3-mediated rapid (within 40 min), low-cost, instrument-free detection method for SARS-CoV-2. This assay, which we call Cas3-Operated Nucleic Acid detectioN (CONAN), not only detects SARS-CoV-2 in clinical samples, but also offers specific detection of single-base-pair mutations in IAV variants. This tool allows rapid and accurate point-of-care testing for patients with suspected SARS-CoV-2 or drug-resistant IAV infections in hospitals.

[The use of nationwide tuberculosis surveillance system data to determine geographical differences in drug resistance--consideration of the representativeness of the drug resistance rate in Japan].

Annual reports of tuberculosis (TB) statistics have been compiled using a database built through the nationwide computerized TB surveillance system in Japan. Using the annual report database for 2007-2009, this study compared the drug resistance rates among eight geographical districts. The proportion of bacteriological test results obtained at public health centers, which enter data into their computers that can then be accessed by the central computer, improved greatly from 2007 to 2009. The proportion of initial culture test results obtained among pulmonary TB increased from 63.8% to 74.8% and the proportion of drug susceptibility test results obtained among culture-positive pulmonary TB cases increased from 41.8% to 63.5%. As a result, susceptibility test results among 15,425 (26.5%) of 58,198 newly notified pulmonary TB cases during the three-year study period were obtained. The proportion of multi-drug resistant (MDR) TB among new treatment patients was 0.6% in the whole country. Although there were no particular districts having a significantly high rate of MDR-TB, the Kinki district showed the highest rate at 0.8%. In the case of retreatment patients, the MDR-TB rate was 5.1% in the whole country and there was no statistical difference among the eight districts. The proportion having resistance to any INH among new treatment patients was 4.5% in the whole country, with the Kinki and Kanto districts showing significantly high rates of 5.3% and 5.2%, respectively. In the case of retreatment patients, the proportion having resistance to any INH was 13.3% in the whole country, and there was no district where the proportion was significantly high. The proportion having resistance to one or more drugs among new treatment patients was 12.7% in the whole country, with the Kinki district showing a significantly higher rate of 15.4%. In the case of retreatment patients, the proportion having resistance to one or more drugs was 22.2% in the whole country, and there was no district where the proportion was significantly high. It is important to monitor drug susceptibility results for a comprehensive TB control program. The results of drug susceptibility tests through the nationwide TB surveillance system revealed a tendency toward higher drug resistance in districts that included large cities. Although many problems remain to be solved in order to optimize the use of results from the nationwide computerized TB surveillance system to represent the drug resistance rates in Japan, this practice is expected to yield great benefits.

Next-generation prebiotic promotes selective growth of bifidobacteria, suppressing Clostridioides difficile.

Certain existing prebiotics meant to facilitate the growth of beneficial bacteria in the intestine also promote the growth of other prominent bacteria. Therefore, the growth-promoting effects of ß-galactosides on intestinal bacteria were analyzed. Galactosyl-ß1,4-l-rhamnose (Gal-ß1,4-Rha) selectively promoted the growth of Bifidobacterium. Bifidobacterium longum subsp. longum 105-A (JCM 31944) has multiple solute-binding proteins belonging to ATP-binding cassette transporters for sugars. Each strain in the library of 11 B. longum subsp. longum mutants, in which each gene of the solute-binding protein was disrupted, was cultured in a medium containing Gal-ß1,4-Rha as the sole carbon source, and only the BL105A_0502 gene-disruption mutant showed delayed and reduced growth compared to the wild-type strain. BL105A_0502 homolog is highly conserved in bifidobacteria. In a Gal-ß1,4-Rha-containing medium, Bifidobacterium longum subsp. infantis JCM 1222T, which possesses BLIJ_2090, a homologous protein to BL105A_0502, suppressed the growth of enteric pathogen Clostridioides difficile, whereas the BLIJ_2090 gene-disrupted mutant did not. In vivo, administration of B. infantis and Gal-ß1,4-Rha alleviated C. difficile infection-related weight loss in mice. We have successfully screened Gal-ß1,4-Rha as a next-generation prebiotic candidate that specifically promotes the growth of beneficial bacteria without promoting the growth of prominent bacteria and pathogens.

[Recent problem of skin lesions induced by BCG vaccination].

PURPOSE: To study the recent trends of occurrence of skin lesions as adverse reactions of vaccination with Bacillus Calmette-Guérin. MATERIALS AND METHODS: The Reports of Vaccination Adverse Reaction Notification by Ministry of Health, Labour & Welfare, and literature retrieved from the Japan Medical Abstract (Centra Medicina Revuo Japana) were reviewed and analysed. RESULTS AND DISCUSSION: There has recently been an increasing incidence of skin tuberculosis-like lesions as adverse reactions of infants in Japan due to BCG vaccination. According to the reporting system of the adverse reaction of vaccinations, the incidence rate per one million vaccinations was 1.7 from 1995 to 2002 but raised to 11.8 from 2003 to 2005. A similar trend is also seen in case reports in publications. A total of 102 cases were reported in the journals and conferences, out of which 74 were (1) generalized skin rash and 23 were (2) localized skin lesions (the remaining five could not be categorized). Type (1) and type (2) lesions roughly correspond to tuberculids and true skin cutaneous tuberculosis (including wart and lupus), respectively, for skin tuberculosis due to Mycobacterium tuberculosis. The recent increase of these reactions is mostly attributed to the increase in the former type of lesions, which may be associated with the concentration of the BCG vaccination among infants especially after 2005 since when the vaccination has been targeted only at those aged less than 6 months under the new vaccination policy. The prognosis of both lesions is quite good. The antituberculosis treatment was given to only 20% of the former cases and 75% of the latter cases (including surgical procedure), and all were cured or subsided. There were several cases with serious underlying conditions such as severe combined immunodeficiency and Kawasaki disease in the former category. CONCLUSION: This type of adverse reaction warrants no serious concern; however, staff members should be able to recognize it adequately so that they can manage it properly and not seriously worry the guardians.

[Comparison of TB incidence of young and middle age groups between urban/suburban prefectures and other prefectures].

PURPOSE: Comparison of TB incidence in young and middle age group between urban/surrounding area and other area. MATERIAL & METHODS: TB incidence in young and middle age group by sex, nationality, labor status and prefecture is calculated with data of National Population Survey and TB surveillance in 2005. Risk factors of TB infection/break down such as public transportation, poverty, population density, diabetes, malignancy, HIV infection, foreigners are compared between urban/surrounding area and other area. RESULTS: TB incidence of employees, jobless and housekeepers in urban/surrounding prefectures is higher than other prefectures, but TB incidence of housekeepers is low and difference is small. Utilization frequency of public transportation is correlated with prefectural level of TB incidence of male and female employees. There is no correlation with prevalence of other risk factors. DISCUSSION: Public transportation and working in urban area is indicated as causes of difference of TB infection risk. Reinforcement of TB control program of working places in urban area is important and if necessary contact survey of TB outbreak at public transportation should be considered. Further analysis using more precise indicators is necessary to elucidate for influence of poverty.

[Female with dentatorubral-pallidoluysian atrophy followed for 14 years from the pre-clinical stage: availability of gait analysis].

We presented a 28-year-old female with dentatorubral-pallidoluysian atrophy (DRPLA) who had been followed from the pre-clinical stage. Her mother and elder brother were diagnosed as DRPLA at autopsy. Though the genetic diagnosis was not performed, we diagnosed this patient as DRPLA from her clinical course and family history. She first visited our hospital at age 14 with a symptoms of mental retardation. Generalized tonic-clonic type epilepsy developed at age 15, and valproate was prescribed from age 24. Gait disturbance and mental deterioration gradually progressed from age 15. We had performed gait analyses and brain MRI studies at regular intervals from age 14 to 27. She could walk even with gait disturbance until her early 20s. At one year after marked ataxia was recorded on gait analysis, she rapidly regressed and became unable to walk. Following this patient over a long period of time presented an opportunity to gather informative data regarding the progression of this disorder.

Motor and cognitive development of children with Down syndrome: The effect of acquisition of walking skills on their cognitive and language abilities.

OBJECTIVE: This study investigated the relationship between motor and cognitive/language development in children with Down syndrome (DS). We also tested the hypothesis that acquisition of walking skills facilitates later cognitive/language development. METHODS: Participants were 156 children with DS who were less than 48 months old and had undergone a health checkup by medical doctors and received rehabilitation treatment between April 2013 and March 2017 in Yokohama, Japan. To assess their development, the Kyoto Scale of Psychological Development (KSPD) 2001 was used, which measures development in three subdomains: Posture-Motor (P-M), Cognitive-Adaptive (C-A), and Language-Social (L-S). To investigate the relationship between motor and cognitive/language development, partial correlation analyses were conducted that controlled for participants' age. To test the effect of achieving walking skills, regression analyses were conducted using only data from participants who took the KSPD at least twice and could not walk at the initial test. RESULTS: P-M developmental age (DA) was significantly and positively correlated with both C-A DA and L-S DA in children 1-3 years old. The relationship strengthened with increased age. Acquisition of walking skills had a significant positive effect on both the C-A DA and L-S DA at the second test when controlling for the C-A DA and L-S DA at the first test and age at the second test. CONCLUSION: Motor development was correlated with both cognitive and language development in young children with DS. Results also suggested that achievement of walking could facilitate later cognitive/language development in children with DS.