Mitochondrial respiratory chain disorder in two Filipino children

Mitochondrial respiratory chain disorders have very diverse manifestations and can present with any symptom, in any organ at any time. Here we describe two Filipino children confirmed to have a mitochondrial respiratory chain disorder after presenting with non-specific neurologic symptoms. The first patient had Otahara syndrome and was later on found to have complex I deficiency. The second patient had the m.8993T>G mtDNA mutation that was consistent with a Leigh phenotype.

Chromosomal structural abnormalities among Filipino couples with recurrent pregnancy losses

Introduction. Recurrent pregnancy loss is a devastating reproductive problem that affects 5% of couples trying to conceive. Majority of the cases are due to cytogenetic errors. This study determines the prevalence of chromosomal structural abnormalities in Filipino couples who presented with 2 or more pregnancy losses. Methods. Results from chromosomal analysis of couples referred for 2 or more miscarriages done at the Institute of Human Genetics-National Institutes of Health-University of the Philippines, Manila on peripheral blood samples from 1991 to 2010 were restrospectively reviewed. Results. There were 356 couples with a history of 2 or more miscarriages sent for chromosomal analysis from 1991-2010 included in this study. Among these 356 couples, 17 couples (4.8%) were found to be carriers of different chromosomal abnormalies. From a total of 18 cases, there were 13(3.6%) translocations, 1(0.3%) insertion, 2(0.6%) with marker chromosomes, 1(0.3%) pericentric inversion and 1(0.3%) deletion. Conclusion. The overall frequency of chromosomal structural abnormalities among patients with RPL in this study is 4.8% with translocations being the most common type detected. The results of this study are similar to that of previous large-scale studies which have demostrated that parental chromosomal abnormalities are associated with RPL.

Characterization of mutations and polymorphisms in the G6PD among Filipino newborns with glucose-6-phosphate dehydrogenase deficiency

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.

Early diagnosis and specialist care in the management of congenital hypothyroidism

Background. Newborn screening for congenital hypothyroidism (CH) in the Philippines was introduced in 1996. It is universally accepted that early detection through newborn screening and timely treatment can improve the physical and neuro-cognitive development of patients. As of December 2010, the prevalence of CH is 1 in 3,324 among 2,389,959 newborns screened. Objective. We sought to evaluate the role of timing of diagnosis, compliance with treatment, and specialist care on growth and development (mental and physical) of patients with congenital hypothyroidism detected through newborn screening. Methods. Of the 326 patients identified through newborn screening between July 1996-December 2008 at the Newborn Screening Center-National Institutes of Health, 86 patients participated in the study. With the parents' or guardians' consent, general physical examination and neuro-cognitive evaluation were done; FT4 and TSH were determined. Prevalence of poor control of disease (high TSH with normal or low FT4 or normal TSH with low FT4), stunting, and cognitive delay were each estimated at 95% confidence level and the associations of early diagnosis, initial and continuing specialist care with these conditions were determined by multiple logistic regression analyses. Results. The prevalences (95% confidence interval) were: poor control of disease 63% (52-73%), stunting 24% (15-34%) and neuro-developmental delay 17% (8-25%). Delay in one aspect of neuro-development was seen in 54% (43-66%). Early diagnosis was protective against poor control of disease (adjusted Odds Ratio, ORa=0.24 [CI: 0.08-0.77]). Trends towards protection were seen for initial and continuing specialist care. For delay in at least one cognetive aspect, early diagnosis was found to be protective (ORa=0.19 [CI 0.05-0.76]); results for specialist care were inconclusive. For stunting, low parent education was found to be a risk factor. (ORa of 5.45 [CI: 1.3-22.7]). Conclusion. Fifty-four percent of the study patients had delay in one aspect of neuro-development. While other factors play a role in the outcome of CH, early diagnosis and treatment were shown to be protective of patients from poor control of disease and cognitive delays. Observed trends of positive benefits of specialist care at onset and continuing medical management, and the association of low parent education with poor growth should be considered in drafting specific guidelines for the long term follow-up care and monitoring of CH patients detected through newborn screening. The low percentage of participation and incomplete retrieval of information are major limitations of this retrospective study. This stresses the need for better monitoring tools that will ensure proper tracking, medical care and evaluation of CH patients.

Intravenous pamidronate treatment in Filipino children with moderate to severe osteogenesis imperfecta

Objective. To present preliminary data on the effects of intravenous pamidronate in children with moderate to severe Osteogenesis Imperfecta (OI). Methods. This is a restrospective study wherein a review of medical records and available serial radiographs of children (N=14) with moderate to severe IO started on pamidronate from 2006 to 2010 was done. Results. Two children have IO Type I, 8 have IO Type III and 4 have IO Type IV. At baseline, 2 had normal height, 8 had height less than minus 2SD and the rest with less than minus 1SD. Twelve out of 14 had vertebral compression fractures. Mean age at start of pamidronate was 5.4 years (range 0.5-11 years). First infusion fever in five patients and transient generalized macular rash in one child were noted. Serum calcium and phosphorus levels were normal at baseline and remained stable. Based on parental report, improvement of motor function was noted. In the 10 children who had at least a year of treatment, long bone fractures decreased from mean annualized fracture rate of 2.6 at baseline to 0.9. In patients with vertebral compression fractures, serial radiographs showed improvement of vertebral shape. Conclusion. This preliminary study shows that treatment was generally well tolerated and led to decrease in long bone fractures, improved vertebral shape and improved function.

Occurrence of birth defects at the Philippine General Hospital: 2001-2010

Introduction. Birth defects are global problem with impact particularly severe in middle - to low -income countries. In the Philippines, there is a limited data on birth defects despite the fact that congenital anomalies have been in the top 10 causes of infant mortality. The objectives of the study were: 1.) to determine the occurrence of birth defects among patients admitted to the Philippine General Hospital (PGH); 2.) To present the distribution of patients by geographic location and age group distribution; 3.) To categorize birth defects by organ systems; and 4.) To categorize birth defects as either isolated, part of a recognizable syndrome, chromosomal syndrome of multi-malformed case. Methods. Patients admitted to PGH from 2001-2010 and to have major structural defects were included in this study. Case ascertainment was done through a review of medical records of all admitted patients age 0 to more than 65 years old. Patients with birth defects was assigned codes of International Classification of Diseases (ICD)-10 classification. Results. Of the 438,944 admissions to the PGH from 2001 to 2010, there were 8,686 (2.0%) patients with a diagnosis of at least one (1) birth defect. The most common birth defects are as follows: digestive system (3,605/8,686 or 41.5%), cardiovascular system (,839/8,686 or 32.7%), nervous system (1,070/8,686 or .3%) and genital organ anomalies (755/8,686 or 8.7%). The common digestive system anomalies were cleft lip and /or palate (1,548/8,686 or 17.8%), imperforate anus (698/8,686 or 8%) and hirschsprung disease (582/8,686 or 6.7%). Most of the cardiovascular system anomalies were congenital malformations of the cardiac septa (1,160/8,686 or 13.4%) and the great arteries (769/8,686 or 8.9%), while almost of the nervous system anomalies were due to congenital hydrocephalus (347/8,686 or 4%), encephalocoele (303/8,686 or 3.5%) and spina bifida (193/8,686 or 2.%) The most common genital organ anomalies were hypospadias (340/8,686 or 3.9%) and undescended testicle (233/8,686 or 2.7%) Majority (4,042/8,686 or 46.5%) of birth defect cases came from the National Capital Region (NCR) while 32.5% (or 2,87/8.686) of the cases came from region IV-A or Cavite, Laguna, Batangas , Rizal and Quezon (CALABARZON) Region. Conclusion. The results of this study show that the most common birth defects are digestive, cardiovascular, nervous system, and genital organ anomalies. This trend is similar to those reported internationally. The findings of the study can be the basis of policies toward the development and implementation of practical strategies for primary and secondary prevention of birth defects among Filipinos.

Establishment of the Philippine birth defects surveillance

Congenital anomalies have been in the top ten causes of infant mortality in the Philippines for the past 50 years. Since there is no synthetic surveillance for the congenital anomalies in our country, there are no specific programs directed toward better understanding of this group of patients. The birth defects surveillance project was convinced in 008 to develop a system of reporting of newborns with birth defects at the hospital and community setting. The lead agencies for this project are the University of the Philippines Manila-National Institutes of Health and the department of Health (DOH). This paper describes the establishment of the Philippine Birth Defects Surveillance.

A master of science in genetic counseling program in the Philippines

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.

A performance evaluation and assessment scheme (PEAS) for improving the Philippine newborn screening program

Newborn Screening in the Philippines began as a small pilot project in Manila in 1996 and has expanded to a nationwide program screening for 5 conditions today. Along the way, professional, political and public support has increased. As a result, a national law requiring the offering of screening to all newborns was put into place. The Department of Health (DOH) is actively providing follow-up support, and the National Institutes of Health - University of the Philippines Manila (NIH) provides laboratory and technical expertise. Expansion has evolved to the point that there are now two DOH accredited screening laboratories with further expansion anticipated. The Newborn Screening Reference Center at the NIH has partnered with the DOH to develop a performance evaluation and assessment scheme (PEAS). The Philippine PEAS is designed to monitor quality and improvements made in the regional DOH screening program. The Philippine PEAS was developed building on a PEAS previously developed by the US National Newborn Screening and Genetics Resource Center, and we report here the development, implementation and results of the Philippine PEAS.

Models for increasing the newborn screening performance of health facilities

Newborn screening (NBS) was introduced in the Philippines in 1996. After 12 years of implementation, a review of performance of the NBS facilities shows that there is a wide range of NBS performance from zero to 100%. This paper aims to review the NBS facilities (NSFs) that have at least 90% NBS coverage and to identify the successful strategies that have pushed the high coverage.

Cost-benefit analysis of the newborn screening program of the Philippines

BACKGROUND: Newborn Screening (NBS) is a public health activity aimed at the early identification of infants who are affected by certain genetic/metabolic/infectious conditions. A cost analysis is critical for national implementation for integration as a public health program. OBJECTIVES: 1) To determine the incidence rates of congenital hypothyroidism (CH), congenital adrenal hyperplasia (CAH), galactosemia (GAL), phenylketonuria (PKU) and glucose-6-phosphate dehydrogenase (G6PD) deficiency; and 2) To determine whether NBS is cost-beneficial for each disorder individually or in combination, from a societal perspective. STUDY DESIGN: Cross sectional survey and cost-benefit analysis. SUBJECTS AND METHODS: The study was conducted through a screening survey of the original 24 Metro Manila hospitals. Newborns were screened for CH, CAH, GAL, PKU and G6PD deficiency after the 24th hour of life. Those who screened positive underwent serum confirmatory testing. Using incidence rates from the screening survey, a population of 1.5 million, and different screening combinations, the costs for the detection and treatment of the five disorders were compared to the benefits projected from preventing the corresponding complications and consequent productivity losses. For economic evaluation, we compared sequential analysis of doing tandem/multiple testing for the different disorders vs a "do-nothing" alternative. Sensitivity analyses for different incidence and discount rates were conducted to test the strength of the conclusions. RESULTS: The incidences of the disorders with 95% confidence intervals are: CH is 1:3 235 (1:2 219 - 1:5 946); CAH is 1:7 455 (1:4 046 - 1: 14245); GAL is 1: 106 006 (1: 44 218-1:266 796); and G6PD deficiency is 1:167 (1:151 - 1: 186). Screened individually, CH and G6PD deficiency had net benefits of US$ 5.29 M and US$ 15.44 M, respectively. The other conditions yielded net costs when screened individually - CAH (US$ 2.61 M), GAL (US$ 0.90 M) and PKU (US$ 6.74 M). Pairing the disorders with CH showed the following benefit:cost ratios - CH + CAH, 1.3; CH + GAL, 2.0; CH + G6PD deficiency, 3.4; and CH + PKU, 0.9. Combining disorders resulted in the following benefit:cost ratios - CH + CAH + GAL, 1.2; CH + CAH + GAL + PKU, 0.8; and CH + CAH + GAL + G6PD deficiency, 2.1. Screening for the 5 disorders in tandem resulted in a benefit:cost ratio of 1.4 and a net benefit of US$ 11.42 M.

Cost-benefit analysis of a neonatal screening program for congenital hypothyroidism in Metro Manila

BACKGROUND: Neonatal mass screening has led to the early diagnosis and management of congenital endocrine and metabolic diseases. The effectiveness and efficiency of neonatal screening had been well established for congenital hypothyroidism (CH) in other settings. OBJECTIVES: 1) To determine the incidence of CH; and 2) To determine whether a newborn screening program (NSP) for CH is cost-beneficial from a societal perspective. DESIGN: Screening survey with cost-benefit analysis. SUBJECTS AND METHODS: Newborns from the original 24 hospitals in Metro Manila that started newborn screening were screened for CH after the 48th hour of life. Confirmatory tests were performed for those who screened positive. Using the incidence from the survey, the costs for the detection and treatment of CH were compared to the projected benefits of preventing the mental retardation and consequent productivity losses. Sensitivity analyses for incidence rates, discount rates and timing of blood collection were included. RESULTS: A total of 28,088 newborns (40% of 69,391 live births) were screened. Ninety-two were recalled for confirmatory testing after the initial screen; 8 were diagnosed with CH. Assuming that a cohort of 200,000 newborns would be screened in one year, the net costs for the screening program were US$ 2.4M. If the timing of blood collection was after the 24th hour, there was instead a net benefit of US$ 0.6M. The incidence of CH among the hospital admissions in Metro Manila was 0.037% (95% CI 0.009 - 0.064%). CONCLUSIONS: The net cost of a screening program for CH taken after 48 hours was US$ 2.4M. Newborn screening for CH was cost-beneficial if blood collection occurred after the 24th hour so that expense of an additional hospital day was not incurred. In order to realize the costing benefits illustrated by this study, the timing of sample collection was moved to a day earlier (after 24 hours of age) beginning in 2000.

Mutations of the phenylalanine hydroxylase (PAH) gene in Filipino patients with phenylketonuria

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.

Mutations of the steroid 21-hydroxylase gene among Filipino patients with congenital adrenal hyperplasia

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.

Improved screening efficiency for phenylketonuria using a modified bacterial inhibition assay protocol- Autoclaving the bloodspot

The Guthrie bacterial inhibition assay (BIA) tests for elevated phenylalanine (PHE) by measuring B. subtilis growth zone density in an agar medium. Dried blood spots with elevated PHE on initial BIA screening undergo repeat BIA testing and thin-layer chromatography (TLC). Specimens with elevated PHE by TLC or BIA on second-tier testing require recall. To streamline PKU screening and reduce the recall rate, we tested a modified BIA protocol incorporating autoclaving of dried blood spots. Autoclaving improves growth zone appearance and has been previously reported to reduce the number of specimen requiring repeat testing. From June to October 2006, dried blood spot samples with initially elevated PHE were autoclaved at 110°C for 5 min, then retested by BIA. Samples with still-elevated PHE were analyzed by TLC. 1078 of 37,268 samples (2.89%) had initially elevated PHE. After autoclaving, 1036 no longer exhibited elevated PHE decreasing to 42 (0.11%) the number requiring TLC. By comparison, the unmodified algorithm resulted in 3.14% of samples received from July - December 2006 requiring both repeat BIA and TLC testing. We have since modified our PKU screening algorithm to require repeat BIA testing from autoclaved samples prior to TLC analysis. This translates to a significant reduction in time and resources for second-tier testing and follow-up, and prevents stress for the parents of a newborn who would have been recalled unnecessarily.

Glucose-6-phosphate dehydrogenase deficiency in Filipino neonates with jaundice

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 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.