1.Genotype-phenotype correlations in Filipino patients with type 3 gaucher disease
Chiong Mary Anne D. ; Silao Catherine Lynn T.
Acta Medica Philippina 2011;45(4):30-34
Gaucher disease is an inherited glycolipid storage disorder caused by a deficiency of the lysosomal enzyme glucocerebrosidase. Clinical manifestations include hepatosplenomegaly, skeletal abnormalities, anemia and thrombocytopenia. We present here the corresponding genotypes and the genotype-phenotype correlations of 3 Filipino patients. Clinical phenotypes and genotypes were documented by reviewing the charts of 3 Filipino patients
with Gaucher disease. Clinical parameters such as liver and spleen sizes, hematologic variables, disease types and response to enzyme replacement therapy were compared. Likewise, quantitative enzyme assays and mutation analysis were reviewed.
All have the type III neuronopathic Gaucher disease. Patients 1 and 2 are twin sisters who both have mild mental retardation with Patient 1 having a concomitant seizure disorder. They have the corresponding genotype of p.L444/p.P319A. Patient 3 has global developmental delay, oculomotor apraxia, pyramidal tract signs and carries the p.L444P/p.G202R/p.G202R genotype. Genotype-phenotype correlations for the 3 patients showed that their genotypes are compatible with the severe neuronopathic type of disease.
GENOTYPE
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GENETIC PHENOMENA
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PHENOTYPE
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GAUCHER DISEASE
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NERVOUS SYSTEM DISEASES
2.Glucose-6-phosphate dehydrogenase deficiency in Filipino neonates with jaundice.
Silao Catherine Lynn T. ; David-Padilla Carmencita ; Uy Esterlita V. ; delos Reyes Ernesto R.
Acta Medica Philippina 2009;43(2):22-25
OBJECTIVES: Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common of all clinically significant enzyme defects of red blood cells. It has a high rate of prevalence in the Philippines. Concern about hemolytic anemia and jaundice due to unrecognized G6PD deficiency led us to determine the prevalence of G6PD deficiency among jaundiced neonates in the Philippine General Hospital, a tertiary referral hospital in the Philippines. It was hypothesized that G6PD deficiency was more prevalent in neonates with jaundice than in the normal population. We also compared the clinical presentation and course (hospital stay and days of phototherapy requirement) for G6PD deficient and G6PD normal neonates.
MATERIALS AND METHODS: We studied 102 clinically jaundiced neonates admitted to the nursery of the Philippine General Hospital. Blood samples in individual microtainers were quantitatively tested for G6PD activity using a commercial G6PD assay kit. The clinical presentation and hospital courses of patients were statistically compared using the t-test for single proportions.
RESULTS: G6PD deficiency was diagnosed in 17 of 102 cases[16.7% (95% CI: 10.0 to 25.3)], which is significantly higher than the normal population (p<0.001). In all G6PD-deficient neonates, no evidence of other factors known to cause hyperbilirubinemia were detected. There was no significant difference on phototherapy requirement and length of hospitalization in G6PD- deficient and other jaundiced neonates.
CONCLUSION: The prevalence of G6PD deficiency among jaundiced neonates was found to be higher than the normal population thus, early detection of this enzymopathy, regardless of sex, and close surveillance of the affected newborns is important in reducing the risk of severe hyperbilirubinemia.
Human ; Male ; Female ; Infant Newborn ; Glucosephosphate Dehydrogenase Deficiency ; Glucosephosphate Dehydrogenase ; Philippines ; Erythrocyte Count ; Erythrocytes ; Hyperbilirubinemia ; Jaundice ; Phototherapy ; Nurseries
4.Association of glutathione-S-transferase M1,P1, and T1 gene polymorphisms with treatment response in childhood acute lymphocytic leukemia.
Dion-Berboso April Grace ; Alcausin Ma. Melanie Liberty B. ; Padilla Carmencita D. ; Fajardo Pamela D. ; Silao Catherine Lynn T.
Acta Medica Philippina 2016;50(2):75-80
There is still a strong need for new treatment strategies that will maintain remission and prolong survival in patients with acute lymphoblastic leukemia (ALL). The glutathione-S-transferase (GST) enzymes, which are coded by highly polymorphic genes, have been associated with the risk of developing cancer and were found to regulate effect of cancer treatment drugs.
OBJECTIVES: The present study determines the association of GSTM1, GSTP1 and GSTT1 polymorphisms and treatment response in terms of occurrence of adverse events and relapse in ALL in Filipino children.
METHODS: This is a follow up study on the 2007 investigation done by Alcausin et al. which determined the association of the GST P1, M1, and T1 polymorphisms and occurrence of ALL. Four-year follow-up data were available for 46 out of the 50 patients from January 2007 to May 2011. Odds ratios (OR) as measures of association of GST M1, P1 and T1 gene polymorphisms with treatment outcomes were estimated at 95% confidence interval.
RESULTS: Results show a trend towards predisposition to elevation of liver enzymes in patients with GSTT1 and GSTP1 mutant genotypes showing an OR (95% Cl) of 2.0 (0.62-6.49). The presence of GSTM1 null genotype showed a trend towards protection from occurrence of relapse basing on both crude and adjusted ORs, 0.58 (0.16-2.07) and 0.23 (0.05-1.20), respectively. However, these results are not statistically significant.
CONCLUSION: The GSTP1 heterozygous genotype conferred increased predisposition to elevation of liver enzymes while the GSTT1 null genotype was shown to be a possible risk factor towards the occurrence of both infection and elevation of liver enzymes during chemotherapy. Furthermore, the GSTM1 null genotype appears to be protective from occurrence of relapse. It is recommended to do similar large-scale studies in the future to obtain more conclusive results.
Human ; Male ; Female ; Child ; Child Preschool ; Child ; Confidence Intervals ; Follow-up Studies ; Genotype ; Glutathione ; Glutathione S-transferase Pi ; Glutathione Transferase ; Liver ; Precursor Cell Lymphoblastic Leukemia-lymphoma ; Recurrence ; Treatment Outcome ; Glutathione S-transferase M1 ; Glutathione S-transferase T1
5.Validation of a PCR-based test for the genetic diagnosis of Filipino patients with X-linked dystonia parkinsonism (Xdp)
Paul Matthew D. Pasco ; Toshitaka Kawarai ; Catherine Lynn T. Silao ; Daffodil M. Canson ; Lillian V. Lee ; Ryuji Kaji
Acta Medica Philippina 2015;49(1):1-4
BACKGROUND AND OBJECTIVE: X-linked dystonia parkinsonism (XDP, DYT3, MIM #314250) is a neurodegenerative movement disorder found endemically in the Philippines. An SVA retrotransposon insertion mutation has been described in patients with XDP, which requires Southern analysis for detection. However, this method is costly and time-consuming. Hence we developed a PCR-based method and validated it among our local population.
METHODS AND RESULTS: A total of 58 samples from 58 patients with a clinical diagnosis of XDP were collected. Other samples were from an obligate female carrier, two unaffected male relatives, and two patients with typical Parkinson’s disease. Primers designed to amplify the SVA retrotransposon found in the DYT3-TAF1 gene (NCBI Accession Number AB191243) were used. All patients were positive for the expected 3229-bp product after PCR amplification. The normal control showed a 599-bp product, while the female carrier showed both the 3229 and 599-bp product. Subsequent RFLP analysis using BamHI verified the presence of the SVA retrotransposon insertion mutation.
CONCLUSION: Our results show that large-scale PCR-based testing to screen for genetic diseases with a relatively high prevalence such as XDP is possible in our setting. When followed by RFLP analysis, this can provide genetic confirmation of the diagnosis of XDP and facilitate proper genetic counselling and therapy.
Dystonia 3, Torsion, X-Linked
6.Mutations of the steroid 21-hydroxylase gene among Filipino patients with congenital adrenal hyperplasia.
Cutiongco-de la Paz Eva Maria ; Abaya Eric Christian ; Silao Catherine Lynn T. ; Capistrano-Estrada Sylvia ; David-Padilla Carmencita
Acta Medica Philippina 2009;43(2):32-35
Congenital adrenal hyperplasia (CAH), an autosomal recessive disorder, is due to deficiency of the enzymes involved in adrenal steroidogenesis. Phenotypic manifestations vary as a result of the degree of glucocorticoid or mineralocorticoid deficiency and androgen excess present. Among Filipinos, the estimated crude incidence of CAH is approximately 1 in 7,000, which is higher than what is reported in most populations. More than 90% of all cases result from a 21-hydroxylase (21-OH) (cytochrome P450c21) enzyme deficiency involving two 21-OH genes, the active gene (CYP21) and a pseudogene (CYP21P). Studies have shown that mutations result from unequal crossover during meiosis which leads to complete deletion of the gene, gene conversion events or to point mutations. To date, there are no published data on the types of mutations present among Filipinos diagnosed with congenital adrenal hyperplasia. The objective of this study is to describe the profile of Filipino patients diagnosed with CAH and to determine the disease-causing alleles in the 21-OH gene of these patients. Using a method of combined differential polymerase chain reaction and amplification created restriction site approach, direct probing for the presence of known mutations in exons 1,3,4,6,7,8 and intron 2 of the CYP21 and CYP21P genes among Filipino patients with CAH was performed. A total of 12 unrelated CAH patients were examined. A majority of these cases had a premature splicing error mutation at nucleotide 656 of intron 2. The determination of the most frequent alleles in our population can facilitate rapid screening for mutations in the 21-OH gene and lead to a definitive diagnosis of CAH.
Human ; Male ; Female ; Steroid 21-hydroxylase ; Adrenal Hyperplasia, Congenital ; Introns ; Glucocorticoids ; Mineralocorticoids ; Alleles ; Pseudogenes ; Rna Splicing ; Nucleotides
7.Mutations of the phenylalanine hydroxylase (PAH) gene in Filipino patients with phenylketonuria.
Silao Catherine Lynn T. ; Canson Daffodil M. ; Hernandez Karen N. ; Chiong Mary Anne D. ; Capistrano-Estrada Sylvia ; David- Padilla Carmencita
Acta Medica Philippina 2009;43(2):36-39
INTRODUCTION: Phenylketonuria (PKU), an autosomal recessive metabolic disorder caused by phenylalanine hydroxylase (PAH) deficiency, leads to hyperphenylalaninemia and neurological damage if untreated. This is the first study in the Philippines to identify the disease-causing mutations in the PAH gene of clinically diagnosed Filipino PKU patients.
METHODS: The study included four unrelated PKU patients detected by the Philippine Newborn Screening Program from 1996 to 2008. Plasma amino acid analyses for all patients showed increased phenylalanine and low to normal tyrosine levels consistent with the diagnosis of PKU. Mutations in the PAH gene were identified by genomic DNA extraction from dried blood spots of the patients, PAH exon amplification by polymerase chain reaction and subsequent bi-directional DNA sequence analysis.
RESULTS: All patients presented with significantly elevated phenylalanine levels on bacterial inhibition assay and thin layer chromatography. Urinary pterins confirmed the diagnosis of Tetrahydrobiopterin deficiency in two patients while the other 2 patients had the Classical PKU phenotype. Four previously identified mutations in the PAH gene (p.I65T, p.R413P, p.EX6-96A>G, p.R243Q) were identified in those with Classical PKU.
CONCLUSION: The present results confirm the heterogeneity of mutations at the PAH locus in Filipinos. Neonatal screening and the use of molecular diagnosis significantly aid in the medical management and genetic counseling of patients and their families.
Phenylalanine Hydroxylase ; Phenylalanine ; Neonatal Screening ; Genetic Counseling ; Tyrosine ; Pterins ; Chromatography, Thin Layer ; Philippines ; Phenylketonurias ; Exons ; Sequence Analysis, Dna ; Phenotype ; Dna
8.A master of science in genetic counseling program in the Philippines
Laurino Mercy Y. ; David-Padilla Carmencita ; Alcausin Maria Melanie B. ; Silao Catherine Lynn T. ; Cutiongco-de la Paz Eva Maria
Acta Medica Philippina 2011;45(4):7-9
In the Philippines, there is an urgent need to expand the clinical services for diagnosis, management and emotional support for patients with genetic conditions and their family members. Despite the lack of trained providers with specialization in genetics, public health related geneticsprograms are continuously being implemented. These address these current demands,strategic planning began in 2009 between local medical geneticists and international genetic professionals to develop the curriculum for an advanced degree in genetic counseling program. The board of regents at the University of the Philippines approved the proposed curriculum in January 2011, and training of the Philippines first cohort of genetic counseling students commenced in June 2011. The successful implementation of the MS of Genetic Counseling program will provide the opportunity to incorporate the match needed genetic counseling services in the country.
Human
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Male
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Female
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GENETIC COUNSELING
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GENETIC SERVICES
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HEALTH SERVICES
9.Characterization of mutations and polymorphisms in the G6PD among Filipino newborns with glucose-6-phosphate dehydrogenase deficiency
David-Padilla Carmencita ; Abaya Christian Eric S. ; Cutiongco-de la Paz Eva Maria ; Silao Catherine Lynn T. ; Shirakawa Taku ; Nishiyama Kauru ; Matsuo Masafumi
Acta Medica Philippina 2011;45(4):53-57
Background. Glucose-6-phosphate (G6PD) deficiency is the most prevalent enzyme deficiency to date. The global prevalence of G6PD deficiency is estimated at around 330 million people affected with the disease worldwide. This 4.9 percent prevalence, correlates highly with geographic areas endemic to malaria. It is the most common among the disorders in the Newborn Screening (NBS) panel in the Philippines, with one confirmed case for every 52 newborns (1:52). This paper determines the molecular background of G6PD deficiency among Filipino newborns detected by newborn screening.
Methods. A total of 200 cases confirmed to have G6PD deficiency, 180 males and 20 females, were identified through the Philippine Newborn Screening Program from 2001-2003. Genomic DNA was extracted from dried blood spots followed by multiplex polymerase chain reaction using multiple tandem forward primers and a common reverse primer (MPTP) to detect previously reported common mutations and polymorphisms in exons 5, 6, 9, 11 and 12 of the G6PD gene.
Results. Of the 200 samples analyzed, mutations and polymorphisms in the G6PD gene were identified in 148 cases (74%). The most common mutation was a G to A transition on nucleotide 871 (Viangchan) of exon 9 in combination with a silent mutation on exon 11, accounting for 32.9% of the cases. This was followed by a C to T transition on nucleotide 1360 (Union) in 21.1 % of the cases. Other mutations were Vanua Lava in 10%, Chatham in 9.4% and Canton in 3.5% of the newborns. The silent polymorphism on nucleotide 1311 was present in 12.9% of cases. There were combinations of these mutations and polymorphisms present in a minority of cases.
Conclusion. Results of this study showed the molecular heterogeneity underlying G6PD deficiency among Filipino newborns.
Human
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Male
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Female
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Infant
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Infant Newborn
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GLUCOSEPHOSPHATE DEHYDROGENASE DEFICIENCY
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HEMIC AND LYMPHATIC DISEASES
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HEMATOLOGIC DISEASES
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ANEMIA
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ANEMIA, HEMOLYTIC
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ANEMIA, HEMOLYTIC, CONGENITAL
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NEONATAL SCREENING
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INFANT, NEWBORN, SCREENING
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NEWBORN INFANT SCREENING
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MUTATION
10.Perspectives on the use of telegenetics services in the Philippines
Catherine Lynn T. Silao, MD, PhD
Acta Medica Philippina 2023;57(8):3-4
The Philippines is a densely populated nation faced with multiple challenges in the healthcare field given its geographic,
cultural, and socioeconomic barriers. Due to the geographic limitations of medical services in the country, many patients
must travel a great distance to referral centers. This was further exacerbated by the Coronavirus disease 2019 (COVID-19)
pandemic, which spread across the world and upended lives. This pandemic triggered a public health crisis that impacted
healthcare systems, healthcare workers, and communities worldwide. It compounded current difficulties with the provision and
accessibility of medical services, necessitating the employment of alternative methods of providing health coverage. As a result,
advanced technological methods for patient diagnosis, monitoring, treatment, and counseling were rapidly implemented.1
Interest in these technological advances began prior to the COVID-19 pandemic, though primarily in developed countries.
However, during this global outbreak, telehealth practices – which refer to online health care services provided by all health
care professions – have seen a rapid increase in popularity.2,3 Telehealth was brought to the forefront in all countries in
order to surmount lockdown constraints, allow continuous provision of health care for patients, and limit exposure to health
systems and health providers.4
Traditional medical education and training were likewise disrupted during this time, resulting in the incorporation
of telehealth into medical education. To reduce the risks associated with more personnel in the hospital, medical students
were withdrawn from clinical environments during the COVID-19 outbreak. This created an environment of uncertainty
and limited clinical exposure, with concerns surrounding progression through the medical course and training program.5
Continuing medical education, which has traditionally been based on clinical knowledge and skills, now requires online
technical communication skills. Innovative services were rapidly developed with health professionals embracing this new
technological competence, enabling general consultation for patients, remote patient monitoring, and self-directed patient
care, thereby decreasing the burden on health facilities. Digital learning platforms also provided an effective way to address the
learning gaps caused by the pandemic.
The restriction of “in-person” delivery of healthcare services due to the global outbreak has prompted physicians, including
clinical geneticists and genetic counselors, to investigate alternative methods of providing health care to patients. A telehealth
innovation for online delivery of clinical genetic and genetic counseling services is the Philippine General Hospital’s Telegenetics
Service. Despite being launched in 2013 to serve genetics patients across the country, this service has since been upgraded
and capitalized resulting in patient appreciation for its COVID-19 exposure prevention, increased access, and time and cost
efficiency. However, the telegenetics service has its limitations.6,7 Despite the expanding scope of telehealth/telegenetics and its
immediate application, issues such as data/patient privacy, organizational readiness, digital maturity, regulatory impediments,
access and acceptance of the technology, geographical and digital disparities, and its integration with traditional medical
services have emerged.8 Lack of a detailed physical examination is also lost in a virtual visit, with focused questions leading to
fragmented, impersonal interactions.
Even when restrictions were lifted, telehealth usage nonetheless remained significantly higher than it had been prior to
the pandemic. This may indicate a shift in public opinion in favor of this innovative medical practice.9 With the expansion of genetic services in the country, there is now a greater need for telegenetics due to the increased demand for clinical genetic and
genetic counseling expertise. Therefore, evidence on the safety and efficacy of this technology in comparison to the traditional
healthcare delivery approach is required. If the technology has the potential to improve health care, we must guarantee its
availability in all resource-limited areas. Future efforts should thus focus on establishing solutions to address the aforementioned
issues and concerns within our healthcare and education systems, thereby ultimately enhancing the standard of medical care.
Philippines
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health care
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COVID-19