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Carmona SMG, Abacan MAR, Alcausin MMLB. Carnitine-acylcarnitine Translocase Deficiency with c.199-10T>G Mutation in Two Filipino Neonates Detected through Parental Carrier Testing. Int J Neonatal Screen 2023; 9:ijns9010004. [PMID: 36648771 PMCID: PMC9844480 DOI: 10.3390/ijns9010004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2022] [Revised: 12/05/2022] [Accepted: 12/26/2022] [Indexed: 01/13/2023] Open
Abstract
Carnitine-acylcarnitine translocase deficiency (CACTD), a fatty acid oxidation defect (FAOD), can present in the neonatal period with non-specific findings and hypoglycemia. A high index of suspicion is needed to recognize the disorder. The case is of a 24-year-old G2P2(2000) mother who sought consultation for recurrent neonatal deaths. The neonates, born two years apart, were apparently well at birth but had a fair cry and no spontaneous eye opening within the first 24 h of life and died before the 72nd hour of life. Newborn screening of both babies revealed elevated long chain acylcarnitines and hypocarnitinemia suggestive of a FAOD. However, due to their early demise, no confirmatory tests were done. Parental carrier testing was performed, revealing both parents to be heterozygous carriers of a pathogenic variant, c.199 10T>G (intronic), in the SLC25A20 gene associated with autosomal recessive CACTD. This is the first reported case of CACTD in the Filipino population.
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Affiliation(s)
- Suzanne Marie G. Carmona
- Department of Pediatrics, Philippine General Hospital, University of the Philippines Manila, Manila 1000, Philippines
- Correspondence:
| | - Mary Ann R. Abacan
- Department of Pediatrics, Philippine General Hospital, University of the Philippines Manila, Manila 1000, Philippines
- Institute of Human Genetics, National Institutes of Health, University of the Philippines Manila, Manila 1000, Philippines
| | - Maria Melanie Liberty B. Alcausin
- Department of Pediatrics, Philippine General Hospital, University of the Philippines Manila, Manila 1000, Philippines
- Institute of Human Genetics, National Institutes of Health, University of the Philippines Manila, Manila 1000, Philippines
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Padilla CD, Therrell BL, Alcausin MMLB, Chiong MAD, Abacan MAR, Reyes MEL, Jomento CM, Dizon-Escoreal MTT, Canlas MAE, Abadingo ME, Posecion JEWC, Abarquez CG, Andal AP, Elizaga ALG, Halili-Mendoza BC, Otayza MPVK, Millington DS. Successful Implementation of Expanded Newborn Screening in the Philippines Using Tandem Mass Spectrometry. Int J Neonatal Screen 2022; 8:ijns8010008. [PMID: 35225931 PMCID: PMC8883932 DOI: 10.3390/ijns8010008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2021] [Revised: 12/23/2021] [Accepted: 01/12/2022] [Indexed: 11/29/2022] Open
Abstract
Newborn bloodspot screening (NBS) began as a research project in the Philippines in 1996 and was mandated by law in 2004. The program initially included screening for five conditions, with a sixth added in 2012. As screening technology and medical knowledge have advanced, NBS programs in countries with developed economies have also expanded, not only in the number of newborns screened but also in the number of conditions included in the screening. Various approaches have been taken regarding selection of conditions to be screened. With limited resources, low- and middle-income countries face significant challenges in selecting conditions for screening and in implementing sustainable screening programs. Building on expansion experiences in the U.S. and data from California on Filipinos born and screened there, the Philippine NBS program has recently completed its expansion to include 29 screening conditions. This report focuses on those conditions detectable through tandem mass spectrometry. Expanded screening was implemented in a stepwise fashion across the seven newborn screening laboratories in the Philippines. A university-based biochemical genetics laboratory provides confirmatory testing. Follow-up care for confirmed cases is monitored and provided through the NBS continuity clinics across the archipelago. Pre-COVID-19 pandemic, the coverage was 91.6% but dropped to 80.4% by the end of 2020 due to closure of borders between cities, provinces, and islands.
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Affiliation(s)
- Carmencita D. Padilla
- Newborn Screening Reference Center, National Institutes of Health, University of the Philippines Manila, Manila 1000, Philippines; (M.M.L.B.A.); (M.E.L.R.); (C.M.J.); (M.T.T.D.-E.); (M.A.E.C.); (M.E.A.)
- Department of Pediatrics, College of Medicine, University of the Philippines Manila, Manila 1000, Philippines; (M.A.D.C.); (M.A.R.A.)
- Institute of Human Genetics, National Institutes of Health, University of the Philippines Manila, Manila 1000, Philippines
- Correspondence:
| | - Bradford L. Therrell
- National Newborn Screening and Global Resource Center, Austin, TX 78759, USA;
- Department of Pediatrics, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - Maria Melanie Liberty B. Alcausin
- Newborn Screening Reference Center, National Institutes of Health, University of the Philippines Manila, Manila 1000, Philippines; (M.M.L.B.A.); (M.E.L.R.); (C.M.J.); (M.T.T.D.-E.); (M.A.E.C.); (M.E.A.)
- Department of Pediatrics, College of Medicine, University of the Philippines Manila, Manila 1000, Philippines; (M.A.D.C.); (M.A.R.A.)
- Institute of Human Genetics, National Institutes of Health, University of the Philippines Manila, Manila 1000, Philippines
| | - Mary Anne D. Chiong
- Department of Pediatrics, College of Medicine, University of the Philippines Manila, Manila 1000, Philippines; (M.A.D.C.); (M.A.R.A.)
- Institute of Human Genetics, National Institutes of Health, University of the Philippines Manila, Manila 1000, Philippines
- Department of Biochemistry, Molecular Biology and Nutrition, Faculty of Medicine and Surgery, University of Santo Tomas, Manila 1008, Philippines
| | - Mary Ann R. Abacan
- Department of Pediatrics, College of Medicine, University of the Philippines Manila, Manila 1000, Philippines; (M.A.D.C.); (M.A.R.A.)
- Institute of Human Genetics, National Institutes of Health, University of the Philippines Manila, Manila 1000, Philippines
| | - Ma. Elouisa L. Reyes
- Newborn Screening Reference Center, National Institutes of Health, University of the Philippines Manila, Manila 1000, Philippines; (M.M.L.B.A.); (M.E.L.R.); (C.M.J.); (M.T.T.D.-E.); (M.A.E.C.); (M.E.A.)
| | - Charity M. Jomento
- Newborn Screening Reference Center, National Institutes of Health, University of the Philippines Manila, Manila 1000, Philippines; (M.M.L.B.A.); (M.E.L.R.); (C.M.J.); (M.T.T.D.-E.); (M.A.E.C.); (M.E.A.)
| | - Maria Truda T. Dizon-Escoreal
- Newborn Screening Reference Center, National Institutes of Health, University of the Philippines Manila, Manila 1000, Philippines; (M.M.L.B.A.); (M.E.L.R.); (C.M.J.); (M.T.T.D.-E.); (M.A.E.C.); (M.E.A.)
| | - Margarita Aziza E. Canlas
- Newborn Screening Reference Center, National Institutes of Health, University of the Philippines Manila, Manila 1000, Philippines; (M.M.L.B.A.); (M.E.L.R.); (C.M.J.); (M.T.T.D.-E.); (M.A.E.C.); (M.E.A.)
| | - Michelle E. Abadingo
- Newborn Screening Reference Center, National Institutes of Health, University of the Philippines Manila, Manila 1000, Philippines; (M.M.L.B.A.); (M.E.L.R.); (C.M.J.); (M.T.T.D.-E.); (M.A.E.C.); (M.E.A.)
| | | | - Conchita G. Abarquez
- Newborn Screening Center—Mindanao, Southern Philippine Medical Center, Davao 8000, Philippines;
| | - Alma P. Andal
- Newborn Screening Center—Southern Luzon, Daniel O. Mercado Medical Center, Tanauan 4232, Philippines;
| | - Anna Lea G. Elizaga
- Newborn Screening Center—National Institutes of Health, Quezon 1101, Philippines;
| | - Bernadette C. Halili-Mendoza
- Newborn Screening Center—Central Luzon, Angeles University Foundation Medical Center, Angeles 2009, Philippines;
| | - Maria Paz Virginia K. Otayza
- Newborn Screening Center—Northern Luzon, Mariano Marcos Memorial Hospital and Medical Center, Batac 2906, Philippines;
| | - David S. Millington
- Department of Pediatrics, Duke University School of Medicine, Durham, NC 27708, USA;
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Maceda EBG, Abadingo ME, Magbanua-Calalo CJ, Dator MA, Resontoc LPR, Castro-Hamoy LD, Abacan MAR, Chiong MAD, Estrada SC. Maple syrup urine disease associated with nephrotic syndrome in a Filipino child. BMJ Case Rep 2021; 14:14/7/e242689. [PMID: 34326111 PMCID: PMC8323351 DOI: 10.1136/bcr-2021-242689] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
A 22-month-old female child with maple syrup urine disease (MSUD) presented with generalised oedema. Diagnostic evaluation revealed nephrotic range proteinuria, hypoalbuminaemia and dyslipidaemia supporting the diagnosis of nephrotic syndrome (NS). Diet, being at the core of the management plan for both MSUD and NS, necessitated regular monitoring and evaluation via dried blood spot collection of leucine. The opposing requirement for total protein for both disorders (that is protein restriction in MSUD and protein supplementation in NS) prompted a careful balancing act of the dietary management. The monitoring, which revealed normal leucine levels on multiple determinations, allowed an eventual increase in dietary protein and daily administration of albumin to address the NS. Dietary protein increase, both in total protein (3.5 g/kg/day) and natural protein (1 g/kg/day) levels, was instituted. It was observed that NS does not trigger leucinosis and allowed easing of protein restriction in MSUD.
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Affiliation(s)
- Ebner Bon G Maceda
- Division of Clinical Genetics, Department of Pediatrics, Philippine General Hospital, University of the Philippines Manila, Manila, Philippines .,Institute of Human Genetics, National Institutes of Health, University of the Philippines Manila, Manila, Philippines
| | - Michelle E Abadingo
- Division of Clinical Genetics, Department of Pediatrics, Philippine General Hospital, University of the Philippines Manila, Manila, Philippines.,Newborn Screening Reference Center, National Institutes of Health, University of the Philippines Manila, Manila, Philippines
| | - Cheryll J Magbanua-Calalo
- Division of Clinical Genetics, Department of Pediatrics, Philippine General Hospital, University of the Philippines Manila, Manila, Philippines.,Newborn Screening Reference Center, National Institutes of Health, University of the Philippines Manila, Manila, Philippines
| | - Melissa A Dator
- Division of Pediatric Nephrology, Department of Pediatrics, Philippine General Hospital, University of the Philippines Manila, Manila, Philippines
| | - Lourdes Paula R Resontoc
- Division of Pediatric Nephrology, Department of Pediatrics, Philippine General Hospital, University of the Philippines Manila, Manila, Philippines
| | - Leniza De Castro-Hamoy
- Division of Clinical Genetics, Department of Pediatrics, Philippine General Hospital, University of the Philippines Manila, Manila, Philippines.,Institute of Human Genetics, National Institutes of Health, University of the Philippines Manila, Manila, Philippines
| | - Mary Ann R Abacan
- Division of Clinical Genetics, Department of Pediatrics, Philippine General Hospital, University of the Philippines Manila, Manila, Philippines.,Institute of Human Genetics, National Institutes of Health, University of the Philippines Manila, Manila, Philippines
| | - Mary Anne D Chiong
- Division of Clinical Genetics, Department of Pediatrics, Philippine General Hospital, University of the Philippines Manila, Manila, Philippines.,Institute of Human Genetics, National Institutes of Health, University of the Philippines Manila, Manila, Philippines.,Department of Biochemistry, Molecular Biology and Nutrition, University of Santo Tomas Faculty of Medicine and Surgery, Manila, Philippines
| | - Sylvia C Estrada
- Division of Clinical Genetics, Department of Pediatrics, Philippine General Hospital, University of the Philippines Manila, Manila, Philippines.,Institute of Human Genetics, National Institutes of Health, University of the Philippines Manila, Manila, Philippines
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Racoma MJC, Calibag MKKB, Cordero CP, Abacan MAR, Chiong MAD. A review of the clinical outcomes in idursulfase-treated and untreated Filipino patients with mucopolysaccharidosis type II: data from the local lysosomal storage disease registry. Orphanet J Rare Dis 2021; 16:323. [PMID: 34289859 PMCID: PMC8293534 DOI: 10.1186/s13023-021-01875-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Accepted: 05/20/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Mucopolysaccharidosis type II (MPS II; Hunter syndrome) is an X-linked multisystem disorder characterized by glycosaminoglycan (GAG) accumulation, caused by a deficiency of iduronate-2-sulfatase (I2S). Enzyme replacement therapy (ERT) with recombinant idursulfase (IDS), the standard of care, was started in the Philippines in 2017. This study reviewed the clinical outcomes in idursulfase-treated and untreated Filipino MPS II patients who were included in the local Lysosomal Storage Disease (LSD) registry of the Institute of Human Genetics-National Institutes of Health (IHG-NIH) from January 1999 to December 2019. METHODS A retrospective audit of records of MPS II patients listed in the registry was done. Qualified patients were divided into two cohorts: idursulfase-treated group (patients on enzyme replacement therapy, ERT, for ≥ 6 months) and untreated group. Baseline characteristics, including demographic data, biochemical results, neurocognitive classification, respiratory involvement, mortality, and adverse events, were recorded. Height, weight, cardiac pathology, liver and spleen sizes, six-minute walking test (6MWT), joint mobility, were determined at baseline and at year 1 and 2 of follow up. RESULTS Forty male patients were included in this review, with only 8 receiving ERT since 2017. The mean age at diagnosis was 6.99 years (SD 4.15; 0.75-20) and mean age at start of ERT was 14.03 years (SD 7.1; 4-21.5), more delayed than previous reports. Eighty percent have early progressive phenotype which was higher than reported average. The early growth pattern differed in our Filipino cohort, but was followed by the expected slowed growth in later years. Improvements in the following endpoints were observed in the treated cohort: height and weight, cardiac disease, liver and spleen sizes, and joint mobility. There were also positive effects on respiratory involvement and mortality rate. Adverse events were consistent with previous reports. CONCLUSIONS ERT is generally well tolerated and effective in reducing GAG storage and improving clinical endpoints among our Filipino MPS II patients. In untreated patients, typical disease progression was observed.
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Affiliation(s)
- Marie Julianne C Racoma
- Division of Clinical and Metabolic Genetics, Department of Pediatrics, Philippine General Hospital, University of the Philippines, Manila, Philippines.
| | | | - Cynthia P Cordero
- Department of Clinical Epidemiology, College of Medicine, University of the Philippines, Manila, Philippines
| | - Mary Ann R Abacan
- Division of Clinical and Metabolic Genetics, Department of Pediatrics, Philippine General Hospital, University of the Philippines, Manila, Philippines
| | - Mary Anne D Chiong
- Institute of Human Genetics, National Institutes of Health, University of the Philippines, Manila, Philippines.,Department of Biochemistry, Molecular Biology and Nutrition, University of Sto.Tomas - Faculty of Medicine & Surgery, Manila, Philippines
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Abadingo ME, Abacan MAR, Basas JRU, Padilla CD. Pregnancy in an adolescent with maple syrup urine disease: Case report. Mol Genet Metab Rep 2021; 27:100745. [PMID: 33868929 PMCID: PMC8042167 DOI: 10.1016/j.ymgmr.2021.100745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 03/07/2021] [Accepted: 03/09/2021] [Indexed: 11/27/2022] Open
Abstract
Maple syrup urine disease (MSUD, MIM #248600) is an autosomal recessive metabolic disorder that results in elevation of the branched-chain amino acids (BCAA) leucine, isoleucine, and valine. Elevation of BCAA and certain alpha keto-acids is associated with a catabolic state and may result in neurological and developmental delays, feeding problems, and a urine and cerumen odor of maple syrup. Pregnancy is a period of multiple adaptations necessary to support fetal growth and development. Both the third trimester of pregnancy and the postpartum period present the possibility for catabolic states. We describe our treatment of an adolescent patient with intermittent MSUD and her resulting positive pregnancy outcome.
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Affiliation(s)
- Michelle E Abadingo
- Division of Clinical and Metabolic Genetics, Department of Pediatrics, University of the Philippines - Philippine General Hospital, Manila, Philippines.,Institute of Human Genetics, National Institutes of Health, University of the Philippines, Manila, Philippines.,Newborn Screening Reference Center, National Institutes of Health, University of the Philippines, Manila, Philippines
| | - Mary Ann R Abacan
- Division of Clinical and Metabolic Genetics, Department of Pediatrics, University of the Philippines - Philippine General Hospital, Manila, Philippines.,Institute of Human Genetics, National Institutes of Health, University of the Philippines, Manila, Philippines
| | - Jeanne Ruth U Basas
- Institute of Human Genetics, National Institutes of Health, University of the Philippines, Manila, Philippines
| | - Carmencita D Padilla
- Division of Clinical and Metabolic Genetics, Department of Pediatrics, University of the Philippines - Philippine General Hospital, Manila, Philippines.,Institute of Human Genetics, National Institutes of Health, University of the Philippines, Manila, Philippines.,Newborn Screening Reference Center, National Institutes of Health, University of the Philippines, Manila, Philippines
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6
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Maceda EBG, Kratz LE, Ramos VME, Abacan MAR. Novel NSDHL gene variant for congenital hemidysplasia with ichthyosiform erythroderma and limb defects (CHILD) syndrome. BMJ Case Rep 2020; 13:13/11/e236859. [DOI: 10.1136/bcr-2020-236859] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
We report a case of a 1-year and 2-month-old girl with clinical features consistent with congenital hemidysplasia with ichthyosis and limb defects syndrome. Sterol analysis from skin flakes revealed increased levels of a mono 4-alpha methyl sterol also seen in plasma as well as the presence of 4-alpha-carboxy-4-methyl-cholest-8(9)-en-3beta-ol and several keto-sterols, which are usually below the limit of detection. This sterol pattern is consistent with abnormal function of the 4-alpha-methylsterol-4-demethylase complex. NSDHL gene testing revealed the presence of a variant of uncertain significance, c.130G>A (p.Gly44Ser). This missense mutation currently is not included in population databases (ExAC no frequency) and has not been reported in individuals with an NSDHL-related condition. Parental studies showed that neither parent carries the NSDHL variant. On this basis, this variant has been reclassified as likely pathogenic. Symptomatic treatment with keratolytic agents, emollients and ketoconazole was initiated.
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Chiong MAD, Racoma MJC, Abacan MAR. Genetic and clinical characteristics of Filipino patients with Gaucher disease. Mol Genet Metab Rep 2018; 15:110-115. [PMID: 30023299 PMCID: PMC6047105 DOI: 10.1016/j.ymgmr.2018.03.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Revised: 03/23/2018] [Accepted: 03/23/2018] [Indexed: 12/20/2022] Open
Abstract
Gaucher disease (GD) is a lysosomal storage disorder caused by the deficiency of the β-glucocerebrosidase enzyme due to disease causing mutations in the GBA1 (glucosidase beta acid) gene, leading to the abnormal accumulation of the lipid glucocerebroside in lysosomal macrophages. This is a review of the clinical features and molecular profiles of 14 Filipino patients with GD. Five patients presented with type 1 disease, two had type 2 GD and seven had type 3 GD. The age of onset for all types was between 1 and 2 years of age but there was a delay of 2.2 years from the time of symptom onset to confirmation of diagnosis. Hepatosplenomegaly, anemia and thrombocytopenia were present in most of the patients. Stunting was seen in 64.3% and bone abnormalities were present in 63.6%. The most common mutant allele detected in this cohort was L483P (previously L444P), followed by F252I, P358A and G241R. IVS2+1 G>A, N409S and G416S mutations were reported singularly. There were 3 patients who were found to have N131S mutations and one patient with D257V mutation, mutant alleles that have only been reported among the Filipinos to date. Except for N409S, the mutations found in this cohort were generally severe and were congruent with the severe phenotypes found in most patients. Of the 14 patients, only 6 were able to undergo enzyme replacement therapy which significantly improved the hematologic parameters and decreased the sizes of the liver and spleen but did not consistently improve the growth and skeletal abnormalities nor alleviate the neurological manifestations of our patients with GD. Improved monitoring through recommended modalities for assessments and tools for evaluation should be implemented in order to fully appreciate the severity of the disease and accuracy of the response to treatment.
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Affiliation(s)
- Mary Anne D. Chiong
- Institute of Human Genetics, National Institutes of Health University of the Philippines Manila, Philippines
- Department of Pediatrics, Philippine General Hospital, Manila, Philippines
- University of Santo Tomas, Manila, Philippines
| | - Marie Julianne C. Racoma
- Newborn Screening Reference Center, National Institutes of Health, University of the Philippines, Manila, Philippines
| | - Mary Ann R. Abacan
- Institute of Human Genetics, National Institutes of Health University of the Philippines Manila, Philippines
- Department of Pediatrics, Philippine General Hospital, Manila, Philippines
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Chiong MAD, Canson DM, Abacan MAR, Baluyot MMP, Cordero CP, Silao CLT. Clinical, biochemical and molecular characteristics of Filipino patients with mucopolysaccharidosis type II - Hunter syndrome. Orphanet J Rare Dis 2017; 12:7. [PMID: 28077157 PMCID: PMC5225557 DOI: 10.1186/s13023-016-0558-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2016] [Accepted: 12/21/2016] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND Mucopolysaccharidosis type II, an X-linked recessive disorder is the most common lysosomal storage disease detected among Filipinos. This is a case series involving 23 male Filipino patients confirmed to have Hunter syndrome. The clinical and biochemical characteristics were obtained and mutation testing of the IDS gene was done on the probands and their female relatives. RESULTS The mean age of the patients was 11.28 (SD 4.10) years with an average symptom onset at 1.2 (SD 1.4) years. The mean age at biochemical diagnosis was 8 (SD 3.2) years. The early clinical characteristics were developmental delay, joint stiffness, coarse facies, recurrent respiratory tract infections, abdominal distention and hernia. Majority of the patients had joint contractures, severe intellectual disability, error of refraction, hearing loss and valvular regurgitation on subspecialists' evaluation. The mean GAG concentration was 506.5 mg (SD 191.3)/grams creatinine while the mean plasma iduronate-2-sulfatase activity was 0.86 (SD 0.79) nmol/mg plasma/4 h. Fourteen (14) mutations were found: 6 missense (42.9%), 4 nonsense (28.6%), 2 frameshift (14.3%), 1 exon skipping at the cDNA level (7.1%), and 1 gross insertion (7.1%). Six (6) novel mutations were observed (43%): p.C422F, p.P86Rfs*44, p.Q121*, p.L209Wfs*4, p.T409R, and c.1461_1462insN[710]. CONCLUSION The age at diagnosis in this series was much delayed and majority of the patients presented with severe neurologic impairment. The results of the biochemical tests did not contribute to the phenotypic classification of patients. The effects of the mutations were consistent with the severe phenotype seen in the majority of the patients.
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Affiliation(s)
- Mary Anne D Chiong
- Institute of Human Genetics, National Institutes of Health, University of the Philippines Manila, 625 Pedro Gil St., Ermita, Manila, 1000, Philippines. .,Department of Pediatrics, University of the Philippines-Philippine General Hospital, Manila, Philippines. .,Department of Pediatrics, College of Medicine, University of Santo Tomas, Manila, Philippines.
| | - Daffodil M Canson
- Institute of Human Genetics, National Institutes of Health, University of the Philippines Manila, 625 Pedro Gil St., Ermita, Manila, 1000, Philippines
| | - Mary Ann R Abacan
- Institute of Human Genetics, National Institutes of Health, University of the Philippines Manila, 625 Pedro Gil St., Ermita, Manila, 1000, Philippines.,Department of Pediatrics, University of the Philippines-Philippine General Hospital, Manila, Philippines
| | - Melissa Mae P Baluyot
- Institute of Human Genetics, National Institutes of Health, University of the Philippines Manila, 625 Pedro Gil St., Ermita, Manila, 1000, Philippines.,Department of Pediatrics, University of the Philippines-Philippine General Hospital, Manila, Philippines
| | - Cynthia P Cordero
- Department of Clinical Epidemiology, College of Medicine, University of the Philippines, Manila, Philippines
| | - Catherine Lynn T Silao
- Institute of Human Genetics, National Institutes of Health, University of the Philippines Manila, 625 Pedro Gil St., Ermita, Manila, 1000, Philippines.,Department of Pediatrics, University of the Philippines-Philippine General Hospital, Manila, Philippines
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