YYYee Yee Yap

Yee Yee Yap

*This is an algorithmically generated author record based on publicly available information.

Yee Yee Yap has a total of 36 co-authors. Here are the top co-authors by number of shared publications:


Latest Publications

  • Open Access

    Genomic Alterations, Gene Expression Profiles and Functional Enrichment of Normal-Karyotype Acute Myeloid Leukaemia Based on Targeted Next-Generation Sequencing

    by Angeli Ambayya, Rozaimi Razali, Sarina Sulong, Ezzanie Suffya Zulkefli, Yee Yee Yap, Jameela Sathar, Rosline Hassan

    Characterising genomic variants is paramount in understanding the pathogenesis and heterogeneity of normal-karyotype acute myeloid leukaemia (AML-NK). In this study, clinically significant genomic biomarkers were ascertained using targeted DNA sequencing and RNA sequencing on eight AML-NK patients’ samples collected at disease presentation and after complete remission. In silico and Sanger sequencing validations were performed to validate variants of interest, and they were followed by the performance of functional and pathway enrichment analyses for overrepresentation analysis of genes with somatic variants. Somatic variants involving 26 genes were identified and classified as follows: 18/42 (42.9%) as pathogenic, 4/42 (9.5%) as likely pathogenic, 4/42 (9.5%) as variants of unknown significance, 7/42 (16.7%) as likely benign and 9/42 (21.4%) as benign. Nine novel somatic variants were discovered, of which three were likely pathogenic, in the CEBPA gene with significant association with its upregulation. Transcription misregulation in cancer tops the affected pathways involving upstream genes (CEBPA and RUNX1) that were deregulated in most patients during disease presentation and were closely related to the most enriched molecular function gene ontology category, DNA-binding transcription activator activity RNA polymerase II-specific (GO:0001228). In summary, this study elucidated putative variants and their gene expression profiles along with functional and pathway enrichment in AML-NK patients.


  • Mortality outcomes and survival patterns of patients with myeloproliferative neoplasms in Malaysia

    by Yee Yee Yap, Jameela Sathar, Kian Boon Law

    Background Prognostication of myeloproliferative neoplasm (MPN) has always been challenging, even with the advent of Janus kinase 2 (JAK2 V617F) molecular studies. The survival pattern of patients diagnosed with MPN in developing countries is still undetermined. Materials and methods The national MPN registry conducted from 2009 to 2015 in Malaysia provided a comprehensive insight into the demographics, clinical characteristics and laboratory parameters of patients diagnosed with MPN nationwide. The study analysed the survival patterns and mortality outcomes and risk among 671 patients diagnosed with essential thrombocythaemia (ET), polycythaemia vera (PV), primary myelofibrosis (PMF) and unclassified MPN (MPN-U). Mortality status was traced and confirmed until the end of December 2018, with right censoring applied to patients alive beyond that. Results The analysed cohort consisted of 283 (42.2%) ET, 269 (40.1%) PV, 62 (9.2%) PMF and 57 (8.5%) MPN-U incident cases with diagnosis made between 2007 and 2015. The majority of patients were male (52.3%) and Malay (48.9%), except for ET, in which the majority of patients were female (60.1%) and of Chinese origin (47.0%). Female patients were found to have significantly better overall survival (OS) rates in ET (p = 0.0285) and MPN-U (p = 0.0070). Patients with JAK2 V617F mutation were found to have marginally inferior OS over time. Multivariable Cox regression identified patients with increased age [hazard ratio (HR) 1.055, 95% CI 1.031; 1.064], reduced haemoglobin (HB) level (HR 0.886, 95% CI 0.831; 0.945, p = 0.0002), being male (HR 1.545, 95% CI 1.077; 2.217, p = 0.0182), and having MPN-U (HR 2.383, 95% CI 1.261; 4.503, p = 0.0075) and PMF (HR 1.975, 95% CI 1.054; 3.701, p = 0.0335) at increased risk for worse mortality outcomes. Conclusion Myeloproliferative neoplasm reduces patient survival. The degree of impact on survival varies according to sub-type, sex, bone marrow fibrosis and HB levels. The JAK2 V617F mutation was not found to affect the survival pattern or mortality outcome significantly.


  • Open Access

    The mortality outcomes and survival pattern of patients of Myeloproliferative Neoplasms in Malaysia

    by Yee Yee Yap, Jameela Sathar, Kian Boon Law, MPN registry working group

    Background: The prognostication of myeloproliferative neoplasm (MPN) has always been challenging even in the advent of Janus kinase 2 (JAK2 V617F) molecular studies. The survival pattern of MPN in a developing country such as Malaysia is still undetermined.Materials and Methods: This was a retrospective study using information from 774 patients from the National MPN Registry conducted from the year 2009 to 2015 in Malaysia. Patients with the diagnosis of essential thrombocythaemia (ET), polycythaemia vera (PV), primary myelofibrosis (PMF) and unclassified MPN (MPN-U) were included. Survival data were traced until December 2018. Results: The cohort consisted of 42.0% ET, 41.0% PV, 8.9% PMF and 8.1% MPN-U, with 48.8% Malay, 39.1% Chinese, 7.1% Indian, 5.0% Others. The subtypes analysis revealed that male MPNs was more than female MPNs except in ET. The Chinese ethnicity was associated with the highest incidence of ET. The mortality rate was the highest in PMF followed by MPN-U then PV and ET (pConclusion: Patients with ET had the slightly better OS while PMF had the worst OS. This is in conjunction with low haemoglobin, worsening bone marrow fibrosis, splenomegaly, diabetes mellitus, hypertension and bleeding. JAK2 V617F mutation was seemingly resulting in inferior overall survival especially in ET and PMF. The survival outcome of the MPN registry is instrumental for future policy development of effective healthcare in Malaysia.

  • Open Access

    Nevus Lipomatosus Cutaneous Superficialis: A Case Report and Literature Review

    by Raymond Dieu Kiat Yeak, Yee Yee Yap, Nizlan M. Nasir

    Introduction: Nevus lipomatosus cutaneous superficialis (NLCS) is uncommon and can be encountered in various medical specialties. In this study, we report a rare case of solitary pedunculated nevus lipomatosus cutaneous superficialis in a middle-aged female patient and highlight its clinical and histopathological features. Case Presentation: A 43-year-old Malaysian female patient presented to our center with a 2-cm long and 1-cm wide solitary, flesh-colored nodule over the anterolateral aspect of her thigh. Excisional biopsy was performed, and the histopathology report showed NLCS. There are three types of NLCS, namely the solitary, multiple, and generalized forms. The etiology of NLCS is usually idiopathic, with no gender or familial preponderance. NLCS is usually misdiagnosed and should be differentiated from nevus sebaceous, connective tissue nevus, neurofibroma, lymphangioma, hemangioma, and focal dermal hypoplasia (also known as Goltz syndrome). Conclusions: In conclusion, NLCS is rare and benign condition, which should be differentiated from other malignant skin conditions as it is commonly misdiagnosed. Therefore, physicians and surgeons should be aware of its clinical and histopathological features.

  • Open Access

    The epidemiology and clinical characteristics of myeloproliferative neoplasms in Malaysia

    by Yee Yee Yap, Kian Boon Law, Jameela Sathar, Ngee Siang Lau, Ai Sim Goh, Teng Keat Chew, Soo Min Lim, Padmini Menon, Yong Khee Guan, Azlan Bin Husin, et al.

    The evolution of molecular studies in myeloproliferative neoplasms (MPN) has enlightened us the understanding of this complex disease consisting of polycythaemia vera (PV), essential thrombocythemia (ET) and primary myelofibrosis (PMF). The epidemiology is well described in the western world but not in Asian countries like Malaysia. This retrospective national registry of MPN was conducted from year 2009 to 2015 in Malaysia. A total of 1010 patients were registered over a period of 5 years. The mean age was 54 years with male predominance. The ethnic distribution revealed that Chinese had a relatively high weighted incidence proportion (43.2%), followed by Indian (23.8%), Malay (15.8%) and other ethnic groups (17.2%). The types of MPN reported were 40.4% of ET (n = 408), 38.1% of PV (n = 385), 9.2% of PMF (n = 93), 3.1% of hypereosinophilic syndrome (HES) (n = 31) and 7.9% of unclassifiable MPN (MPN-U) (n = 80). Splenomegaly was only palpable clinically in 32.2% of patients. The positive JAK2 V617F mutation was present in 644 patients with 46.6% in PV, 36.0% in ET, 9.0% in PMF, and 7.4% in MPN-U, and had significantly lower haemoglobin (p < 0.001), haematocrit (p < 0.001) and white blood cells (WBC) (p < 0.001) than those with negative mutation. Significant differences in platelet and WBC count were detected in ethnic groups and MPN sub-types. There were more arterial thrombosis events seen in those with JAK2 V617F mutation as compared to venous thrombosis events (23.1% vs 4.4%). The bleeding rate was only 6.6%. Among the risk factors, previous thrombosis, old age (≥ 60 years) and hypertension were significantly correlated to positive JAK2 V617F mutation. The arterial thrombosis event is associated with higher presenting HB, HCT and PLT while the bleeding event is associated with lower presenting HB, HCT but higher PLT. The presence of JAK2 V617F mutation is associated with higher risk of arterial thrombosis. Chinese ethnicity is associated with higher rates of MPN. The history of thrombosis, age ≥ 60 years and hypertension are risk factors that can be correlated to JAK2 V617F mutation. This study is instrumental for policy makers to ensure preventive strategies can be implemented in future.


  • Open Access

    Clinical characteristics and outcomes of thrombotic microangiopathy in Malaysia

    by Yee Yee Yap, Jameela Sathar, Kian Boon Law, Putri Astina Binti Zulkurnain, Syed Carlo Edmund, Kian Meng Chang, Ross Baker

    Yap YY, et al. Blood Res. 2018 Jun;53(2):130-137. https://doi.org/10.5045/br.2018.53.2.130