Project description:ObjectiveTo evaluate the effectiveness of whole-genome array comparative genomic hybridization (aCGH) in prenatal diagnosis in Hong Kong.MethodsArray CGH was performed on 220 samples recruited prospectively as the first-tier test study. In addition 150 prenatal samples with abnormal fetal ultrasound findings found to have normal karyotypes were analyzed as a 'further-test' study using NimbleGen CGX-135K oligonucleotide arrays.ResultsArray CGH findings were concordant with conventional cytogenetic results with the exception of one case of triploidy. It was found in the first-tier test study that aCGH detected 20% (44/220) clinically significant copy number variants (CNV), of which 21 were common aneuploidies and 23 had other chromosomal imbalances. There were 3.2% (7/220) samples with CNVs detected by aCGH but not by conventional cytogenetics. In the 'further-test' study, the additional diagnostic yield of detecting chromosome imbalance was 6% (9/150). The overall detection for CNVs of unclear clinical significance was 2.7% (10/370) with 0.9% found to be de novo. Eleven loci of common CNVs were found in the local population.ConclusionWhole-genome aCGH offered a higher resolution diagnostic capacity than conventional karyotyping for prenatal diagnosis either as a first-tier test or as a 'further-test' for pregnancies with fetal ultrasound anomalies. We propose replacing conventional cytogenetics with aCGH for all pregnancies undergoing invasive diagnostic procedures after excluding common aneuploidies and triploidies by quantitative fluorescent PCR. Conventional cytogenetics can be reserved for visualization of clinically significant CNVs.
Project description:Forty seven healthy HK-Chinese subjects between ages 18-30 were recruited. Subjects need to pass the McMonnies Questionnaire prior to the data collection. Visual functions and anterior ocular health were first assessed. One hour later, the subjects’ tear osmolalities were tested by the TearLab Osmometer. Tear samples were then collected by disposable microcapillary tubes. TripleTOF 6600 Mass Spectrometer was used to analyze the tear protein components.
Project description:We report the nearly complete genome of a norovirus GII.4 Hong Kong[P31] variant (GII strain Hu/HK/2019/GII.4 Hong Kong[P31]/CUHK-NS-2200) that was detected in a patient with gastroenteritis in August 2019. The genome was sequenced by metagenomic next-generation sequencing and was found to have 92.8% nucleotide similarity to the closest GII.4 norovirus sequence in GenBank.
Project description:The project aim is to evaluate the role of whole-genome aCGH for prenatal diagnosis in Hong Kong. Array CGH was performed on 220 samples recruited prospectively as the first-tier test study; and on 150 samples with abnormal ultrasound findings and normal karyotypes as a further-test study using NimbleGen CGX-135K oligonucleotide arrays. After the exclusion of common aneuploidies in the first-tier study, clinically significant CNVs are detected in 23/220 samples. In the further test study, clinically significant CNVs are detected in 9/150 samples, which showed CGX array has an increased diagnostic yield of about 6% compared with conventional cytogenetic methods. CNVs of unclear clinical significance are detected in only 10/370 (2.7%) samples. Only data from sample with positive findings are included in this experiment submission (the samples with normal results are not included here).
Project description:As high-throughput genetic marker screening systems are essential for a range of genetics studies and plant breeding applications, the International RosBREED SNP Consortium (IRSC) has utilized the Illumina Infinium® II system to develop a medium- to high-throughput SNP screening tool for genome-wide evaluation of allelic variation in apple (Malus×domestica) breeding germplasm. For genome-wide SNP discovery, 27 apple cultivars were chosen to represent worldwide breeding germplasm and re-sequenced at low coverage with the Illumina Genome Analyzer II. Following alignment of these sequences to the whole genome sequence of 'Golden Delicious', SNPs were identified using SoapSNP. A total of 2,113,120 SNPs were detected, corresponding to one SNP to every 288 bp of the genome. The Illumina GoldenGate® assay was then used to validate a subset of 144 SNPs with a range of characteristics, using a set of 160 apple accessions. This validation assay enabled fine-tuning of the final subset of SNPs for the Illumina Infinium® II system. The set of stringent filtering criteria developed allowed choice of a set of SNPs that not only exhibited an even distribution across the apple genome and a range of minor allele frequencies to ensure utility across germplasm, but also were located in putative exonic regions to maximize genotyping success rate. A total of 7867 apple SNPs was established for the IRSC apple 8K SNP array v1, of which 5554 were polymorphic after evaluation in segregating families and a germplasm collection. This publicly available genomics resource will provide an unprecedented resolution of SNP haplotypes, which will enable marker-locus-trait association discovery, description of the genetic architecture of quantitative traits, investigation of genetic variation (neutral and functional), and genomic selection in apple.
Project description:BackgroundRecent genome-wide association studies of colorectal cancer (CRC) have identified common single-nucleotide polymorphisms (SNPs) mapping to 10 independent loci that confer modest increased risk. These studies have been conducted in European populations and it is unclear whether these observations generalise to populations with different ethnicities and rates of CRC.MethodsAn association study was performed on 892 CRC cases and 890 controls recruited from the Hong Kong Chinese population, genotyping 32 SNPs, which were either associated with CRC in previous studies or are in close proximity to previously reported risk SNPs.ResultsTwelve of the SNPs showed evidence of an association. The strongest associations were provided by rs10795668 on 10p14, rs4779584 on 15q14 and rs12953717 on 18q21.2. There was significant linear association between CRC risk and the number of independent risk variants possessed by an individual (P=2.29 × 10(-5)).ConclusionThese results indicate that some previously reported SNP associations also impact on CRC risk in the Chinese population. Possible reasons for failure of replication for some loci include inadequate study power, differences in allele frequency, linkage disequilibrium structure or effect size between populations. Our results suggest that many associations for CRC are likely to generalise across populations.
Project description:BackgroundFew studies have evaluated the medication burden borne by survivors of pediatric cancer. This study aimed to describe the drug utilization pattern of chronic medications in a cohort of young pediatric cancer survivors.MethodsThis was a population-based study of patients diagnosed with cancer at age 18 years or younger between 2000 and 2013 in Hong Kong and who had survived at least 5 years postdiagnosis. The primary outcome is the use of any chronic medication (medications that were prescribed for ≥30 consecutive days within a 6-month period). Multivariable log-binomial models were used to identify factors associated with chronic medication use. Kaplan-Meier analysis was used to present the cumulative proportion of survivors initiated on a chronic medication across time from cancer diagnosis.ResultsOf the 2444 survivors (median age = 22 years, interquartile range = 16-27 years), 669 (27.4%) required at least 1 chronic medication at least 5 years postdiagnosis. Survivors who developed a chronic health condition (CHC) had a 5.48 (95% confidence interval [CI] = 4.49 to 6.71) times higher risk of taking a chronic medication than those without CHC. At 10 years postdiagnosis, the cumulative proportion of survivors being initiated a chronic medication was 33.4% (95% CI = 31.1% to 35.6%) for the overall cohort. Higher cumulative proportions were observed in survivors with endocrine (74.6%, 95% CI = 68.4% to 79.6%), renal (68.8%, 95% CI = 54.2% to 78.7%), neurological (58.6%, 95% CI = 46.1% to 68.1%), and cardiovascular (54.7%, 95% CI = 44.0% to 63.4%) disorders.ConclusionSurvivors with certain CHCs had a higher risk of starting a prescription medication in the early phase of survivorship. Future studies include examining the impact of medication burden on survivors' functional status.