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Yiu RSW, Ling TK, Ko CH, Poon SWY, Poon GWK, Wong FCK, Law CY, Iwayama H, Lam CW. Allan-Herndon-Dudley syndrome in Hong Kong: Implication for newborn screening. Clin Chim Acta 2023; 551:117621. [PMID: 37925810 DOI: 10.1016/j.cca.2023.117621] [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] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 08/21/2023] [Accepted: 10/27/2023] [Indexed: 11/07/2023]
Abstract
BACKGROUND Allan-Herndon-Dudley syndrome (MCT 8 deficiency) is an X-linked recessive condition caused by hemizygous pathogenic variants in SLC16A2 encoding the monocarboxylate transporter 8 (MCT8). Patients present with global developmental delay and neurological impairment, and abnormal serum thyroid function tests. The drug, 3,3',5 triiodothyroacetic acid (TRIAC), was recently demonstrated to improve the endocrinological profile. Improvement in diagnostic approach is key to earlier start of treatment. PATIENT FINDINGS We described four Chinese patients with MCT8 deficiency undergoing different diagnostic odysseys. Their initial presentation included global developmental delay and dystonia. Patient 2 also had epilepsy. Patients 1 and 2 presented with two novel variants: (1)hemizygous NM_006517.4(SLC16A2):c.1170 + 2 T > A; p.(?), and (2)hemizygous NM_006517.4(SLC16A2):c.305dupT; p.(Val103GlyfsTer17) respectively. Patients 3 and 4 were biological brothers harboring hemizygous NM_006517.4(SLC16A2):c.305dupT; p.(Val103GlyfsTer17), which was first reported in 2004. We obtained the measurement of triiodothyronine (T3) and reverse T3 (rT3) from dried blood spot samples collected on Day 1 of life from Patient 1 and studied the biomarkers (rT3 and T3/rT3 ratio) proposed by Iwayama et al. for the detection of MCT8 deficiency at birth. Our data verified the significantly reduced rT3 level in Patient 1, compared with healthy newborns, although low T3 level and comparable T3/rT3 ratio with controls were detected. SUMMARY Patients with MCT8 deficiency often undergo diagnostic odysseys. An early diagnosis could be missed by a normal newborn thyroid function screening result based on biochemical measurement of TSH and/or T4/fT4. Early detection of rT3 is key to improving current diagnostic approach. CONCLUSION We recommend that full thyroid function profile (TSH, T4/fT4, T3/fT3, rT3) be considered early for all pediatric patients presenting with unexplained developmental delay and/or dystonia. The potential inclusion of rT3 measurement in newborn screening may prove promising.
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Affiliation(s)
- Rachel Sze-Wan Yiu
- Division of Chemical Pathology, Department of Pathology, Queen Mary Hospital, Hong Kong, China
| | - Tsz-Ki Ling
- Division of Chemical Pathology, Department of Pathology, Queen Mary Hospital, Hong Kong, China
| | - Chun-Hung Ko
- Department of Paediatrics and Adolescent Medicine, Caritas Medical Centre, Hong Kong, China
| | - Sarah Wing-Yiu Poon
- Department of Paediatrics and Adolescent Medicine, Queen Mary Hospital, Hong Kong, China
| | - Grace Wing-Kit Poon
- Department of Paediatrics and Adolescent Medicine, Queen Mary Hospital, Hong Kong, China
| | - Felix Chi-Kin Wong
- Division of Chemical Pathology, Department of Pathology, Queen Mary Hospital, Hong Kong, China
| | - Chun-Yiu Law
- Division of Chemical Pathology, Department of Pathology, Queen Mary Hospital, Hong Kong, China
| | - Hideyuki Iwayama
- Department of Pediatrics, Aichi Medical University, Nagakute, Japan
| | - Ching-Wan Lam
- Division of Chemical Pathology, Department of Pathology, Queen Mary Hospital, Hong Kong, China; Department of Pathology, The University of Hong Kong, Hong Kong, China.
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Ip WCT, Shea YF, Ling TK, Law CY, Lam CW, Chiu PKC. A curious case of early-onset dementia. Hong Kong Med J 2023; 29:359.e1-359.e3. [PMID: 37316159 DOI: 10.12809/hkmj2210106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023] Open
Affiliation(s)
- W C T Ip
- Department of Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong SAR, China
| | - Y F Shea
- Department of Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong SAR, China
| | - T K Ling
- Division of Chemical Pathology, Department of Pathology, Queen Mary Hospital, Hong Kong SAR, China
| | - C Y Law
- Division of Chemical Pathology, Department of Pathology, Queen Mary Hospital, Hong Kong SAR, China
| | - C W Lam
- Division of Chemical Pathology, Department of Pathology, Queen Mary Hospital, Hong Kong SAR, China
- Department of Pathology, The University of Hong Kong, Hong Kong SAR, China
| | - P K C Chiu
- Department of Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong SAR, China
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Ip WCT, Shea YF, Tong HF, Law CY, Lam CW, Chiu PKC. A curious case of small vessel vascular dementia. Hong Kong Med J 2023; 29:174.e1-174.e3. [PMID: 37088704 DOI: 10.12809/hkmj2210093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/25/2023] Open
Affiliation(s)
- W C T Ip
- Department of Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong SAR, China
| | - Y F Shea
- Department of Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong SAR, China
| | - H F Tong
- Division of Chemical Pathology, Department of Pathology, Queen Mary Hospital, Hong Kong SAR, China
- Department of Pathology, Princess Margaret Hospital, Hong Kong SAR, China
| | - C Y Law
- Division of Chemical Pathology, Department of Pathology, Queen Mary Hospital, Hong Kong SAR, China
| | - C W Lam
- Division of Chemical Pathology, Department of Pathology, Queen Mary Hospital, Hong Kong SAR, China
- Department of Pathology, The University of Hong Kong, Hong Kong SAR, China
| | - P K C Chiu
- Department of Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong SAR, China
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Law CY, Lam CW. C-terminal truncated SPOP, a Janus-faced variant, causing a mixed type 1 and type 2 Nabais Sa-de Vries syndrome. Clin Chim Acta 2022; 535:187-194. [PMID: 36063898 DOI: 10.1016/j.cca.2022.08.019] [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] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 08/09/2022] [Accepted: 08/19/2022] [Indexed: 11/26/2022]
Abstract
Nabais Sa-de Vries syndrome (NSDVS) is an autosomal dominant neurodevelopmental disorder first described in 2020 and is classified into type 1 (NSDVS1) and type 2 (NSDVS2) which encompassed of spectrum of distinct clinical features due to gain-of-function (GOF) and loss-of-function (LOF) variants respectively. So far only 6 cases of 5 different missense pathogenic variants had been reported which impact on the SPOP substrate binding affinity for the downstream ubiquitylation. Here, we report a novel and de novo heterozygous nonsense pathogenic variant, p.Tyr353Term at the BACK domain in a patient with neurodevelopmental delay plus mixed phenotypes of NSDVS type 1 and 2 using trio exome analysis. The BACK domain is functionally critical for the SPOP higher-order oligomerization and is shown to increase substrate binding avidity with enhanced ubiquitylation efficiency in vitro. Experimentally, a missense variant p.Tyr353Glu is proven to attenuate the tandem SPOP oligomer formation and we envisage the current truncated variant at the same residue would attenuate the oligomerization process. This is the first report providing in vivo clue about the clinical significance of SPOP oligomerization in human neurodevelopmental disorders with new understanding on the expanding spectrum of NSDVS. We conclude the p.Tyr353Term is a Janus-faced variant which explains the dual NSDVS type 1 and 2 phenotypes in this case.
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Affiliation(s)
- Chun-Yiu Law
- Division of Chemical Pathology, Department of Pathology, Queen Mary Hospital, Hong Kong Special Administrative Region
| | - Ching-Wan Lam
- Division of Chemical Pathology, Department of Pathology, Queen Mary Hospital, Hong Kong Special Administrative Region; Department of Pathology, The University of Hong Kong, Hong Kong Special Administrative Region.
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Chua GT, Wong JSC, Chung J, Lam I, Kwong J, Leung K, Law CY, Lam CW, Kwok J, Chu PWK, Au EYL, Lam CK, Mak D, Fong NC, Leung D, Wong WHS, Ho MHK, Tsao SSL, Wong CS, Yam JC, Tso WWY, To KKW, Tam PKH, Chan GCF, Leung WH, Yuen KY, Novelli V, Klein N, Levin M, Whitaker E, Lau YL, Ip P, Kwan MYW. Paediatric multisystem inflammatory syndrome temporally associated with SARS-CoV-2: a case report. Hong Kong Med J 2022; 28:76-78. [DOI: 10.12809/hkmj219689] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Affiliation(s)
- Gilbert T Chua
- Department of Paediatrics and Adolescent Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
| | - Joshua SC Wong
- Department of Paediatrics and Adolescent Medicine, Princess Margaret Hospital, Hong Kong
| | - Jaime Chung
- Department of Paediatrics and Adolescent Medicine, Princess Margaret Hospital, Hong Kong
| | - Ivan Lam
- Department of Paediatrics and Adolescent Medicine, Princess Margaret Hospital, Hong Kong
| | - Joyce Kwong
- Haematology Laboratory, Department of Pathology, Princess Margaret Hospital, Hong Kong
| | - Kate Leung
- Haematology Laboratory, Department of Pathology, Princess Margaret Hospital, Hong Kong
| | - CY Law
- Division of Chemical Pathology, Department of Pathology, Queen Mary Hospital, Hong Kong
| | - CW Lam
- Department of Pathology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
| | - Janette Kwok
- Division of Transplantation and Immunogenetics, Department of Pathology, Queen Mary Hospital, Hong Kong
| | - Patrick WK Chu
- Division of Transplantation and Immunogenetics, Department of Pathology, Queen Mary Hospital, Hong Kong
| | - Elaine YL Au
- Division of Clinical Immunology, Department of Pathology, Queen Mary Hospital, Hong Kong
| | - Crystal K Lam
- Division of Clinical Immunology, Department of Pathology, Queen Mary Hospital, Hong Kong
| | - Daniel Mak
- Department of Paediatrics and Adolescent Medicine, Princess Margaret Hospital, Hong Kong
| | - NC Fong
- Department of Paediatrics and Adolescent Medicine, Princess Margaret Hospital, Hong Kong
| | - Daniel Leung
- Department of Paediatrics and Adolescent Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
| | - Wilfred HS Wong
- Department of Paediatrics and Adolescent Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
| | - Marco HK Ho
- Department of Paediatrics and Adolescent Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
| | - Sabrina SL Tsao
- Department of Paediatrics and Adolescent Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
| | - Christina S Wong
- Division of Dermatology, Department of Medicine, Queen Mary Hospital, Hong Kong
| | - Jason C Yam
- Department of Ophthalmology and Visual Sciences, Chinese University of Hong Kong, Hong Kong
| | - Winnie WY Tso
- Department of Paediatrics and Adolescent Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
| | - Kelvin KW To
- Department of Microbiology, Carol Yu Centre for Infection, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
| | - Paul KH Tam
- Division of Paediatric Surgery, Department of Surgery, The University of Hong Kong, Hong Kong; Dr Li Dak-Sum Research Centre, The University of Hong Kong–Karolinska Institutet Collaboration in Regenerative Medicine, The University of Hong Kong, Hong Kong
| | - Godfrey CF Chan
- Department of Paediatrics and Adolescent Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
| | - WH Leung
- Department of Paediatrics and Adolescent Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
| | - KY Yuen
- Department of Microbiology, Carol Yu Centre for Infection, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
| | - Vas Novelli
- Department of Paediatric Infectious Diseases, Great Ormond Street Hospital for Children, London, United Kingdom; Institute of Child Health, University College London, London, United Kingdom
| | - Nigel Klein
- Department of Paediatric Infectious Diseases, Great Ormond Street Hospital for Children, London, United Kingdom; Institute of Child Health, University College London, London, United Kingdom
| | - Michael Levin
- Section of Paediatrics, Imperial College London, London, United Kingdom
| | - Elizabeth Whitaker
- Paediatric Infectious Diseases Department, Imperial College Healthcare NHS Trust, London, United Kingdom
| | - YL Lau
- Department of Paediatrics and Adolescent Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
| | - Patrick Ip
- Department of Paediatrics and Adolescent Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
| | - Mike YW Kwan
- Department of Paediatrics and Adolescent Medicine, Princess Margaret Hospital, Hong Kong
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Law CY, Kwok AMK, Ling TK, Wong KC, Lau NKC, Poon GWK, Lam CW. Nuclear magnetic resonance spectroscopy-based urinalysis for a young girl with extreme hypoglycaemia. Pathology 2021; 54:505-508. [PMID: 34702582 DOI: 10.1016/j.pathol.2021.07.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 07/13/2021] [Accepted: 07/21/2021] [Indexed: 10/20/2022]
Affiliation(s)
- Chun-Yiu Law
- Division of Chemical Pathology, Department of Pathology, Queen Mary Hospital, Hong Kong, China
| | | | - Tsz-Ki Ling
- Division of Chemical Pathology, Department of Pathology, Queen Mary Hospital, Hong Kong, China
| | - Ka-Chung Wong
- Division of Chemical Pathology, Department of Pathology, Queen Mary Hospital, Hong Kong, China
| | - Nike Kwai-Cheung Lau
- Division of Chemical Pathology, Department of Pathology, Queen Mary Hospital, Hong Kong, China
| | - Grace Wing-Kit Poon
- Department of Paediatrics and Adolescent Medicine, Queen Mary Hospital, Hong Kong, China
| | - Ching-Wan Lam
- Division of Chemical Pathology, Department of Pathology, Queen Mary Hospital, Hong Kong, China; Department of Pathology, The University of Hong Kong, Hong Kong, China.
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Ling TK, Wong KC, Chan CY, Lau NKC, Law CY, Lee HCH, Lai CK, Chong YK, Yau KCE, Cheung KM, Ko CH, Fung CW, Lee LK, Wong SSN, Mak CM, Chan AYW, Tam S, Lam CW. Urine organic acid as the first clue towards aromatic L-amino acid decarboxylase (AADC) deficiency in a high prevalence area. Clin Chim Acta 2021; 521:40-44. [PMID: 34161777 DOI: 10.1016/j.cca.2021.06.025] [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] [Received: 06/08/2021] [Revised: 06/17/2021] [Accepted: 06/18/2021] [Indexed: 10/21/2022]
Abstract
BACKGROUND Aromatic L-amino acid decarboxylase deficiency is a rare neurometabolic disease due to impaired decarboxylation of neurotransmitter precursors to its active form. CASE We retrospectively reviewed 8 cases from 2008 to 2019 with cerebrospinal fluid neurotransmitter analysis performed at our centre. All cases had an elevated urine vanillactic acid and, in most cases, with N-acetylvanilalanine detected. Cerebrospinal fluid analysis showed low downstream metabolites vanillylmandelic acid, homovanillic acid but high 3-O-methyl-L-DOPA, 5-hydroxytryptophan. Cerebrospinal fluid pterins were normal. Genotyping in DDC confirms the diagnosis. Urine organic acid analysis provided the first clue to diagnosis in four of the cases, which then triggered cerebrospinal fluid neurotransmitter and genetic analysis. We also developed a diagnostic decision support system to assist the interpretation of the mass spectrometry data from urine organic acids. CONCLUSIONS Urine organic acid could be essential in guiding subsequent investigations for the diagnosis of aromatic L-amino acid decarboxylase deficiency. We propose to screen suspected cases first with urine organic acids, specifically looking for vanillactic acid and N-acetylvanilalanine. Suggestive findings should be followed with target analysis for c.714 + 4A > T in ethnically Chinese patients. The assistive tool allowed expedite interpretation of profile data generated from urine organic acids analysis. It may also reduce interpreter's bias when peaks of interest are minor peaks in the spectrum.
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Affiliation(s)
- Tsz-Ki Ling
- Department of Pathology, Queen Mary Hospital, Hong Kong, China
| | - Ka-Chung Wong
- Department of Pathology, Queen Mary Hospital, Hong Kong, China
| | - Candace Yim Chan
- Department of Pathology, Princess Margaret Hospital, Hong Kong, China
| | | | - Chun-Yiu Law
- Department of Pathology, Queen Mary Hospital, Hong Kong, China
| | | | - Chi-Kong Lai
- Department of Pathology, Princess Margaret Hospital, Hong Kong, China
| | - Yeow-Kuan Chong
- Department of Pathology, Princess Margaret Hospital, Hong Kong, China
| | - Kin-Cheong Eric Yau
- Department of Paediatrics and Adolescent Medicine, Princess Margaret Hospital, Hong Kong, China
| | - Ka-Ming Cheung
- Department of Paediatrics and Adolescent Medicine, Caritas Medical Centre, Hong Kong, China
| | - Chun-Hung Ko
- Department of Paediatrics and Adolescent Medicine, Caritas Medical Centre, Hong Kong, China
| | - Cheuk-Wing Fung
- Department of Paediatrics and Adolescent Medicine, Hong Kong Children's Hospital, Hong Kong, China
| | - Lai-Ka Lee
- Department of Paediatrics and Adolescent Medicine, Hong Kong Children's Hospital, Hong Kong, China
| | - Sheila Suet-Na Wong
- Department of Paediatrics and Adolescent Medicine, Hong Kong Children's Hospital, Hong Kong, China
| | - Chloe M Mak
- Department of Pathology, Hong Kong Children's Hospital, Hong Kong, China
| | - Albert Yan-Wo Chan
- Department of Pathology, Hong Kong Children's Hospital, Hong Kong, China
| | - Sidney Tam
- Department of Pathology, Queen Mary Hospital, Hong Kong, China
| | - Ching-Wan Lam
- Department of Pathology, Queen Mary Hospital, Hong Kong, China; Department of Pathology, The University of Hong Kong, Hong Kong, China.
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Law CY, Leung SC, Loong F, Ling TK, Wong KC, Lau NKC, Tsui SH, Lai CL, Lam CW. Serum ceruloplasmin monitoring in a case of silver intoxication due to intravenous silver infusion. Clin Toxicol (Phila) 2021; 60:255-258. [PMID: 34047646 DOI: 10.1080/15563650.2021.1919692] [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: 10/21/2022]
Abstract
INTRODUCTION Colloidal silver packaged as a dietary supplement is readily available online and is thought to be safe. Literature describing its toxicity in humans is scarce. CASE REPORT A 47-year-old man presented to us for sensory and gait problems. He had unremarkable past health except dystrophic nails. He further volunteered a history of receiving chronic oral and intravenous administration of colloidal silver. We confirmed his plasma silver was 1200-fold elevated, measuring 11990 nmol/L (normal < 10 nmol/L). He had deranged liver function tests, and liver biopsy showed distorted acinar architecture, bridging fibrosis and lymphocytic infiltrate with silver particles clustering along the vascular endothelium and portal venules. Brain magnetic resonance imagining showed features of mineralization over bilateral globus pallidi. There was biochemical evidence of central adrenal insufficiency, intracellular iron overload and hypoceruloplasminemia (<0.05 g/L). Gradual clinical and biochemical improvement was noted after silver cessation: his plasma silver dropped to 4800 nmol/L (3 months) and 1650 nmol/L (12 months), and serum ceruloplasmin reverted to 0.13 g/L (10 months) and 0.29 g/L (20 months). CONCLUSIONS The potential effects of silver to liver and copper metabolism were shown in this case. Serum ceruloplasmin also serves as a surrogate marker in monitoring silver intoxication.
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Affiliation(s)
- Chun-Yiu Law
- Division of Chemical Pathology, Department of Pathology, Queen Mary Hospital, Hong Kong, China
| | - Siu-Chung Leung
- Accident and Emergency Department, Queen Mary Hospital, Hong Kong, China.,Emergency Medicine Unit, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Florence Loong
- Division of Anatomical Pathology, Department of Pathology, Queen Mary Hospital, Hong Kong, China
| | - Tsz-Ki Ling
- Division of Chemical Pathology, Department of Pathology, Queen Mary Hospital, Hong Kong, China
| | - Ka-Chung Wong
- Division of Chemical Pathology, Department of Pathology, Queen Mary Hospital, Hong Kong, China
| | - Nike Kwai-Cheung Lau
- Division of Chemical Pathology, Department of Pathology, Queen Mary Hospital, Hong Kong, China
| | - Sik-Hon Tsui
- Accident and Emergency Department, Queen Mary Hospital, Hong Kong, China
| | - Ching-Lung Lai
- Division of Gastroenterology & Hepatology, Department of Medicine, The University of Hong Kong, Hong Kong, China
| | - Ching-Wan Lam
- Division of Chemical Pathology, Department of Pathology, Queen Mary Hospital, Hong Kong, China.,Department of Pathology, The University of Hong Kong, Hong Kong, China
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Lam CW, Fong NC, Chan TYC, Lau KC, Ling TK, Mak DWY, Cheng X, Law CY. Centrosome-associated CDC25B is a novel disease-causing gene for a syndrome with cataracts, dilated cardiomyopathy, and multiple endocrinopathies. Clin Chim Acta 2020; 504:81-87. [PMID: 32027886 DOI: 10.1016/j.cca.2020.01.017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 01/07/2020] [Accepted: 01/17/2020] [Indexed: 11/16/2022]
Abstract
We describe a unique Chinese girl who presented with intrauterine growth retardation, delayed development, bilateral cataracts, hypothyroidism, growth hormone deficiency, and juvenile dilated cardiomyopathy. She was born to consanguineous parents with a history of one fetal and one infantile death in the family. She died from cardiac failure at the age of 12. In the pursuit of a diagnosis, the family was referred to the Clinics for Rare Diseases Referral and the University of Hong Kong Undiagnosed Disease Program. Whole-exome sequencing analysis revealed a homozygous non-sense variant, NM_021873:c.313G > T (p.Glu105*), in the CDC25B gene, a key regulator of the cell cycle. This variant was located in a region of homozygosity of 25 Mb on chromosome 20. Her parents and two asymptomatic sisters were confirmed to be carriers and one brother did not carry the variant. This is the first report of a natural human knockout of the CDC25B gene. Multiple endocrinopathies and fatal juvenile dilated cardiomyopathy suggests the potential for unfavorable complications in oncology patients receiving CDC25B inhibitors as an emerging targeted therapy.
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Affiliation(s)
- Ching-Wan Lam
- Department of Pathology, The University of Hong Kong, Queen Mary Hospital, Hong Kong, China.
| | - Nai-Chung Fong
- Department of Paediatrics & Adolescent Medicine, Princess Margaret Hospital, Hong Kong, China
| | | | - Kwai-Cheung Lau
- Department of Pathology, Princess Margaret Hospital, Hong Kong, China
| | - Tsz-Ki Ling
- Division of Chemical Pathology, Department of Pathology, Queen Mary Hospital, Hong Kong, China
| | - Daniel Wai-Yau Mak
- Department of Paediatrics & Adolescent Medicine, Princess Margaret Hospital, Hong Kong, China
| | - Xinqi Cheng
- Department of Clinical Laboratory, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing 100730, China
| | - Chun-Yiu Law
- Division of Chemical Pathology, Department of Pathology, Queen Mary Hospital, Hong Kong, China
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Pandian BG, Sireesha P, Ng YP, Raj SD, Law CY, Patrick CEM. Assessing the knowledge of private university students on self-medication practices, Malaysia. ACTA ACUST UNITED AC 2019. [DOI: 10.4103/mtsp.mtsp_13_19] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Mak CM, Chen SP, Mok NS, Siu WK, Lee HH, Ching CK, Tsui PT, Fong NC, Yuen YP, Poon WT, Law CY, Chong YK, Chan YW, Yung TC, Fan KY, Lam CW. Genetic basis of channelopathies and cardiomyopathies in Hong Kong Chinese patients: a 10-year regional laboratory experience. Hong Kong Med J 2018; 24:340-349. [PMID: 29497013 DOI: 10.12809/hkmj176870] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
INTRODUCTION Hereditary channelopathies and cardiomyopathies are potentially lethal and are clinically and genetically heterogeneous, involving at least 90 genes. Genetic testing can provide an accurate diagnosis, guide treatment, and enable cascade screening. The genetic basis among the Hong Kong Chinese population is largely unknown. We aimed to report on 28 unrelated patients with positive genetic findings detected from January 2006 to December 2015. METHODS Sanger sequencing was performed for 28 unrelated patients with a clinical diagnosis of channelopathies or cardiomyopathies, testing for the following genes: KCNQ1,KCNH2,KCNE1,KCNE2, and SCN5A, for long QT syndrome; SCN5A for Brugada syndrome; RYR2 for catecholaminergic polymorphic ventricular tachycardia; MYH7 and MYBPC3 for hypertrophic cardiomyopathy; LMNA for dilated cardiomyopathy; and PKP2 and DSP for arrhythmogenic right ventricular dysplasia/cardiomyopathy. RESULTS There were 17 males and 11 females; their mean age at diagnosis was 39 years (range, 1-80 years). The major clinical presentations included syncope, palpitations, and abnormal electrocardiography findings. A family history was present in 13 (46%) patients. There were 26 different heterozygous mutations detected, of which six were novel-two in SCN5A (NM_198056.2:c.429del and c.2024-11T>A), two in MYBPC3 (NM_000256.3:c.906-22G>A and c.2105_2106del), and two in LMNA (NM_170707.3:c.73C>A and c.1209_1213dup). CONCLUSIONS We have characterised the genetic heterogeneity in channelopathies and cardiomyopathies among Hong Kong Chinese patients in a 10-year case series. Correct interpretation of genetic findings is difficult and requires expertise and experience. Caution regarding issues of non-penetrance, variable expressivity, phenotype-genotype correlation, susceptibility risk, and digenic inheritance is necessary for genetic counselling and cascade screening.
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Affiliation(s)
- C M Mak
- Chemical Pathology Laboratory, Kowloon West Cluster Laboratory Genetic Service, Department of Pathology, Princess Margaret Hospital, Laichikok, Hong Kong
| | - S Pl Chen
- Department of Pathology, Princess Margaret Hospital, Laichikok, Hong Kong
| | - N S Mok
- Department of Medicine, Princess Margaret Hospital, Laichikok, Hong Kong
| | - W K Siu
- Department of Pathology, Princess Margaret Hospital, Laichikok, Hong Kong
| | - H Hc Lee
- Department of Pathology, Princess Margaret Hospital, Laichikok, Hong Kong
| | - C K Ching
- Department of Pathology, Princess Margaret Hospital, Laichikok, Hong Kong
| | - P T Tsui
- Department of Medicine, Princess Margaret Hospital, Laichikok, Hong Kong
| | - N C Fong
- Department of Paediatrics and Adolescent Medicine, Princess Margaret Hospital, Laichikok, Hong Kong
| | - Y P Yuen
- Department of Pathology, Princess Margaret Hospital, Laichikok, Hong Kong
| | - W T Poon
- Department of Pathology, Princess Margaret Hospital, Laichikok, Hong Kong
| | - C Y Law
- Department of Pathology, Princess Margaret Hospital, Laichikok, Hong Kong
| | - Y K Chong
- Department of Pathology, Princess Margaret Hospital, Laichikok, Hong Kong
| | - Y W Chan
- Department of Pathology, Princess Margaret Hospital, Laichikok, Hong Kong
| | - T C Yung
- Department of Paediatric Cardiology, Queen Mary Hospital, Pokfulam, Hong Kong
| | - K Yy Fan
- Department of Cardiac Medicine, Grantham Hospital, Wong Chuk Hang, Hong Kong
| | - C W Lam
- Department of Pathology, The University of Hong Kong, Pokfulam, Hong Kong
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Abstract
Aim To study the adequacy of trauma documentation in accident and emergency (A&E) attendance records. Method We reviewed the A&E attendance records of major trauma requiring trauma-team care in the resuscitation room from January to June 1999 and July to December 2001. Thirty-eight items including the history, symptoms and signs of injury were scored with reference to the teaching of the Advanced Trauma Life Support course. The mean score and rate of documentation of each item were calculated. Additional items on biomechanics and environmental factors of injury were also examined. The performance of emergency medicine trainees and non-emergency medicine trainees was analysed. Results A total of 128 records were included, 46 and 82 records being from 1999 and 2001 respectively. The maximum documentation score was 38. The mean documentation score in 2001 was 23.27; and this was significantly better than 20.37 in 1999 (p < 0.05). The documentation rates of pre-hospital, biomechanics and environmental items were poor. Notably, 15 out of the 38 items were preformatted in the A&E records and 11 of these preformatted items had documentation rates of > 80%. Emergency medicine trainees had better scores in 2001 than in 1999. However, non-emergency medicine trainees did not show improvement in their documentation. Conclusion Trauma documentation has improved since 1999 for emergency medicine trainees. Preformatted charts may increase the rate of documentation. Information on pre-hospital care and injury mechanism was not well documented.
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Lam CW, Wong KS, Leung HW, Law CY. Limb girdle myasthenia with digenic RAPSN and a novel disease gene AK9 mutations. Eur J Hum Genet 2016; 25:192-199. [PMID: 27966543 DOI: 10.1038/ejhg.2016.162] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Revised: 10/04/2016] [Accepted: 10/18/2016] [Indexed: 12/19/2022] Open
Abstract
Though dysfunction of neuromuscular junction (NMJ) is associated with congenital myasthenic syndrome (CMS), the proteins involved in neuromuscular transmission have not been completely identified. In this study, we aimed to identify a novel CMS gene in a consanguineous family with limb-girdle type CMS. Homozygosity mapping of the novel CMS gene was performed using high-density single-nucleotide polymorphism microarrays. The variants in CMS gene were identified by whole-exome sequencing (WES) and Sanger sequencing. A 20 MB-region of homozygosity (ROH) was mapped on chromosome 6q15-21. This was the only ROH that present in all clinically affected siblings and absent in all clinically unaffected siblings. WES showed a novel variant of AK9 gene located in this ROH. This variant was a start-gain mutation and introduced a cryptic 5'-UTR signal in intron 5 of the AK9 gene. The normal splicing signal would be interfered by the cryptic translation signal leading to defective splicing. Another 25 MB-ROH was found on chromosome 11p13-q12 in all siblings. WES showed a homozygous RAPSN pathogenic variant in this ROH. Since RAPSN-associated limb-girdle type CMS was only manifested in AK9 homozygous variant carriers, the disease phenotype was of digenic inheritance, and was determined by the novel disease modifier AK9 which provides NTPs for N-glycosylation. This is the first time that this specific genotype-phenotype correlation is reported. Importantly, the AK9-associated nucleotide deficiency may replete by dietary supplements. Since AK9 is a disease modifier, enhancing N-glycosylation by increasing dietary nucleotides may be a new therapeutic option for CMS patients.
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Affiliation(s)
- Ching-Wan Lam
- Department of Pathology, The University of Hong Kong, Hong Kong, China
| | - Ka-Sing Wong
- Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Hong Kong, China
| | - Ho-Wan Leung
- Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Hong Kong, China
| | - Chun-Yiu Law
- Department of Pathology, The University of Hong Kong, Hong Kong, China
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Law CY, Yeung WL, Cheung YF, Chan HF, Fung E, Hui J, Yung IO, Yuen YP, Chan AO, Lam CW. A common PRRT2 mutation in familial paroxysmal kinesigenic dyskinesia in Hong Kong: a case series of 16 patients. Hong Kong Med J 2016; 22:619-22. [PMID: 27920401 DOI: 10.12809/hkmj154579] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Affiliation(s)
- C Y Law
- Department of Pathology, The University of Hong Kong, Pokfulam, Hong Kong
| | - W L Yeung
- Department of Paediatrics and Adolescent Medicine, Alice Ho Miu Ling Nethersole Hospital, Tai Po, Hong Kong
| | - Y F Cheung
- Division of Neurology, Department of Medicine, Queen Elizabeth Hospital, Jordan, Hong Kong
| | - H F Chan
- Division of Neurology, Department of Medicine, Queen Elizabeth Hospital, Jordan, Hong Kong
| | - E Fung
- Department of Paediatrics, Prince of Wales Hospital, Shatin, Hong Kong
| | - J Hui
- Department of Paediatrics, Prince of Wales Hospital, Shatin, Hong Kong
| | - I Ok Yung
- Division of Neurology, Department of Medicine and Therapeutics, Prince of Wales Hospital, Shatin, Hong Kong
| | - Y P Yuen
- Department of Chemical Pathology, Prince of Wales Hospital, Shatin, Hong Kong
| | - A Ok Chan
- Division of Clinical Biochemistry, Queen Mary Hospital, Pokfulam, Hong Kong
| | - C W Lam
- Department of Pathology, The University of Hong Kong, Pokfulam, Hong Kong
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To KKW, Lee KC, Wong SSY, Sze KH, Ke YH, Lui YM, Tang BSF, Li IWS, Lau SKP, Hung IFN, Law CY, Lam CW, Yuen KY. Lipid metabolites as potential diagnostic and prognostic biomarkers for acute community acquired pneumonia. Diagn Microbiol Infect Dis 2016; 85:249-54. [PMID: 27105773 PMCID: PMC7173326 DOI: 10.1016/j.diagmicrobio.2016.03.012] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [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: 08/04/2015] [Revised: 03/02/2016] [Accepted: 03/11/2016] [Indexed: 02/03/2023]
Abstract
Early diagnosis of acute community-acquired pneumonia (CAP) is important in patient triage and treatment decisions. To identify biomarkers that distinguish patients with CAP from non-CAP controls, we conducted an untargeted global metabolome analysis for plasma samples from 142 patients with CAP (CAP cases) and 97 without CAP (non-CAP controls). Thirteen lipid metabolites could discriminate between CAP cases and non-CAP controls with area-under-the-receiver-operating-characteristic curve of >0.8 (P ≤ 10−9). The levels of glycosphingolipids, sphingomyelins, lysophosphatidylcholines and L-palmitoylcarnitine were higher, while the levels of lysophosphatidylethanolamines were lower in the CAP cases than those in non-CAP controls. All 13 metabolites could distinguish CAP cases from the non-infection, extrapulmonary infection and non-CAP respiratory tract infection subgroups. The levels of trihexosylceramide (d18:1/16:0) were higher, while the levels of lysophosphatidylethanolamines were lower, in the fatal than those of non-fatal CAP cases. Our findings suggest that lipid metabolites are potential diagnostic and prognostic biomarkers for CAP. Thirteen lipid metabolites could discriminate CAP cases from non-CAP controls. The levels of 2 lipid metabolites differ between fatal and non-fatal CAP cases. Lipid metabolites are potential diagnostic and prognostic biomarkers for CAP.
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Affiliation(s)
- Kelvin K W To
- State Key Laboratory for Emerging Infectious Diseases, The University of Hong Kong, Hong Kong SAR, China; Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong SAR, China; Research Centre of Infection and Immunology, The University of Hong Kong, Hong Kong SAR, China; Department of Microbiology, The University of Hong Kong, Hong Kong SAR, China
| | - Kim-Chung Lee
- Department of Microbiology, The University of Hong Kong, Hong Kong SAR, China
| | - Samson S Y Wong
- State Key Laboratory for Emerging Infectious Diseases, The University of Hong Kong, Hong Kong SAR, China; Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong SAR, China; Research Centre of Infection and Immunology, The University of Hong Kong, Hong Kong SAR, China; Department of Microbiology, The University of Hong Kong, Hong Kong SAR, China
| | - Kong-Hung Sze
- Department of Microbiology, The University of Hong Kong, Hong Kong SAR, China
| | - Yi-Hong Ke
- Department of Microbiology, The University of Hong Kong, Hong Kong SAR, China
| | - Yin-Ming Lui
- Department of Microbiology, The University of Hong Kong, Hong Kong SAR, China
| | - Bone S F Tang
- Department of Pathology, Hong Kong Sanatorium Hospital, Hong Kong SAR, China
| | - Iris W S Li
- Department of Microbiology, The University of Hong Kong, Hong Kong SAR, China
| | - Susanna K P Lau
- State Key Laboratory for Emerging Infectious Diseases, The University of Hong Kong, Hong Kong SAR, China; Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong SAR, China; Research Centre of Infection and Immunology, The University of Hong Kong, Hong Kong SAR, China; Department of Microbiology, The University of Hong Kong, Hong Kong SAR, China
| | - Ivan F N Hung
- State Key Laboratory for Emerging Infectious Diseases, The University of Hong Kong, Hong Kong SAR, China; Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong SAR, China; Research Centre of Infection and Immunology, The University of Hong Kong, Hong Kong SAR, China; Department of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Chun-Yiu Law
- Department of Pathology, The University of Hong Kong Hong Kong SAR, China
| | - Ching-Wan Lam
- Department of Pathology, The University of Hong Kong Hong Kong SAR, China
| | - Kwok-Yung Yuen
- State Key Laboratory for Emerging Infectious Diseases, The University of Hong Kong, Hong Kong SAR, China; Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong SAR, China; Research Centre of Infection and Immunology, The University of Hong Kong, Hong Kong SAR, China; Department of Microbiology, The University of Hong Kong, Hong Kong SAR, China.
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Law CY, Chang STL, Cho SY, Yau EKC, Ng GSF, Fong NC, Lam CW. Clinical whole-exome sequencing reveals a novel missense pathogenic variant of GNAO1 in a patient with infantile-onset epilepsy. Clin Chim Acta 2015; 451:292-6. [PMID: 26485252 DOI: 10.1016/j.cca.2015.10.011] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Revised: 10/13/2015] [Accepted: 10/13/2015] [Indexed: 02/08/2023]
Abstract
BACKGROUND The cause of infantile-onset epilepsy is complex and is not easily recognized clinically, particularly in paediatric patients who present with non-specific neurological signs, no radiological abnormalities and no metabolic changes. CASE We report a case of infantile-onset epilepsy in a 10-month-old Chinese girl who presented with non-specific neurological signs, no radiological abnormalities and no biochemical disturbances. She first presented at birth with twitching movements and convulsions of an unknown aetiology. Ambulatory EEG showed epileptic rhythmic activities, the presence of asynchrony and runs of sharp waves over the right parietal and central areas. Given the non-specific neurological features and negative structural and biochemical findings, we applied clinical whole-exome sequencing (WES) to determine the underlying aetiology. WES revealed a novel heterozygous missense pathogenic variant, GNAO1:NM_020988.2:c.118G>A; NP_066268.1:p.Gly40Arg. A genetic analysis of the family confirmed the variant identified is a de novo mutation. CONCLUSIONS Clinical WES can streamline genetic analysis and sort out pathogenic genes in an unbiased approach. GNAO1 is a disease-causing gene for the autosomal dominant form of early infantile epileptic encephalopathy. The novel pathogenic variant identified in this case should contribute to our understanding of the expanding spectrum of infantile-onset epilepsy.
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Affiliation(s)
- Chun-Yiu Law
- Department of Pathology, The University of Hong Kong, Hong Kong, China
| | | | - Sun Young Cho
- Department of Laboratory Medicine, School of Medicine, Kyung Hee University, Seoul, Korea
| | - Eric Kin-Cheong Yau
- Department of Paediatrics and Adolescent Medicine, Princess Margaret Hospital, Hong Kong, China
| | - Grace Sui-Fun Ng
- Department of Paediatrics and Adolescent Medicine, Princess Margaret Hospital, Hong Kong, China
| | - Nai-Chung Fong
- Department of Paediatrics and Adolescent Medicine, Princess Margaret Hospital, Hong Kong, China
| | - Ching-Wan Lam
- Department of Pathology, The University of Hong Kong, Hong Kong, China.
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To KKW, Lee KC, Wong SSY, Lo KC, Lui YM, Jahan AS, Wu AL, Ke YH, Law CY, Sze KH, Lau SKP, Woo PCY, Lam CW, Yuen KY. Lipid mediators of inflammation as novel plasma biomarkers to identify patients with bacteremia. J Infect 2015; 70:433-44. [PMID: 25727996 DOI: 10.1016/j.jinf.2015.02.011] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2014] [Revised: 02/16/2015] [Accepted: 02/20/2015] [Indexed: 12/19/2022]
Abstract
OBJECTIVES Rapid diagnostic tests for bacteremia are important for early treatment to improve clinical outcome. We sought to identify plasma biomarkers that can identify patients with bacteremia using an untargeted global metabolomic analysis. METHODS Plasma metabolomic profiles were analyzed for 145 adult patients with (cases) and without (controls) bacteremia using ultra-high-performance liquid chromatography/quadrupole-time-of-flight mass spectrometry (UHPLC-Q-TOF-MS). All metabolites were compared between cases and controls using a 2-tier filtering approach, and each metabolite underwent receiver operating characteristic (ROC) curve analysis. Individual metabolites that distinguish between cases and controls were characterized. Subgroup analysis was performed to identify metabolites with prognostic significance. RESULTS After 2-tier filtering, 128 molecular features were identified to be potential biomarkers that could distinguish cases from controls. Five metabolites had an area under the ROC curve (AUC) of >0.8 in ROC curve analysis, including a sphingolipid, an acylcarnitine, a fatty acid ester, and 2 glycerophosphocholines. These metabolites could distinguish cases from controls in the unsupervised hierarchical clustering analysis. Subgroup analysis of bacteremic patients showed that the level of trans-2,3,4-trimethoxycinnamate was lower in fatal than non-fatal cases. CONCLUSIONS Plasma lipid mediators of inflammation can distinguish bacteremia cases from non-bacteremia controls. These biomarkers may be used as targets for rapid test in clinical practice.
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Affiliation(s)
- Kelvin K W To
- State Key Laboratory for Emerging Infectious Diseases, The University of Hong Kong, Hong Kong, China; Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong, China; Research Centre of Infection and Immunology, The University of Hong Kong, Hong Kong, China; Department of Microbiology, The University of Hong Kong, Hong Kong, China
| | - Kim-Chung Lee
- Department of Microbiology, The University of Hong Kong, Hong Kong, China
| | - Samson S Y Wong
- State Key Laboratory for Emerging Infectious Diseases, The University of Hong Kong, Hong Kong, China; Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong, China; Research Centre of Infection and Immunology, The University of Hong Kong, Hong Kong, China; Department of Microbiology, The University of Hong Kong, Hong Kong, China
| | - Ka-Ching Lo
- Department of Microbiology, The University of Hong Kong, Hong Kong, China
| | - Yin-Ming Lui
- Department of Microbiology, The University of Hong Kong, Hong Kong, China
| | - Akhee S Jahan
- Department of Microbiology, The University of Hong Kong, Hong Kong, China
| | - Andrea L Wu
- Department of Microbiology, The University of Hong Kong, Hong Kong, China
| | - Yi-Hong Ke
- Department of Microbiology, The University of Hong Kong, Hong Kong, China
| | - Chun-Yiu Law
- Department of Pathology, The University of Hong Kong, Hong Kong, China
| | - Kong-Hung Sze
- Department of Microbiology, The University of Hong Kong, Hong Kong, China
| | - Susanna K P Lau
- State Key Laboratory for Emerging Infectious Diseases, The University of Hong Kong, Hong Kong, China; Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong, China; Research Centre of Infection and Immunology, The University of Hong Kong, Hong Kong, China; Department of Microbiology, The University of Hong Kong, Hong Kong, China
| | - Patrick C Y Woo
- State Key Laboratory for Emerging Infectious Diseases, The University of Hong Kong, Hong Kong, China; Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong, China; Research Centre of Infection and Immunology, The University of Hong Kong, Hong Kong, China; Department of Microbiology, The University of Hong Kong, Hong Kong, China
| | - Ching-Wan Lam
- Department of Pathology, The University of Hong Kong, Hong Kong, China
| | - Kwok-Yung Yuen
- State Key Laboratory for Emerging Infectious Diseases, The University of Hong Kong, Hong Kong, China; Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong, China; Research Centre of Infection and Immunology, The University of Hong Kong, Hong Kong, China; Department of Microbiology, The University of Hong Kong, Hong Kong, China.
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Lam CW, Law CY, Leung KF, Lai CK, Pak-lam Chen S, Chan B, Chan KY, Yuen YP, Mak CM, Yan-wo Chan A. NMR-based urinalysis for rapid diagnosis of β-ureidopropionase deficiency in a patient with Dravet syndrome. Clin Chim Acta 2015; 440:201-4. [PMID: 25445412 DOI: 10.1016/j.cca.2014.10.030] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Revised: 10/17/2014] [Accepted: 10/21/2014] [Indexed: 10/24/2022]
Abstract
BACKGROUND Beta-ureidopropionase deficiency is a rare inborn error of metabolism (IEM) affecting pyrimidine metabolism. To-date, about 30 genetically confirmed cases had been reported. The clinical phenotypes of this condition are variable; some patients were asymptomatic while some may present with developmental delay or autistic features. In severe cases, patients may present with profound neurological deficit including hypotonia, seizures and mental retardation. Using NMR-based urinalysis, this condition can be rapidly diagnosed within 15 min. CASE An 11-month-old Chinese boy had dual molecular diagnoses, β-ureidopropionase deficiency and Dravet syndrome. He presented with intractable and recurrent convulsions, global developmental delay and microcephaly. Urine organic acid analysis using GC-MS and NMR-based urinalysis showed excessive amount of β-ureidopropionic acid and β-ureidoisobutyric acid, the two disease-specific markers for β-ureidopropionase deficiency. Genetic analysis confirmed homozygous known disease-causing mutation UPB1 NM_016327.2: c.977G>A; NP_057411.1:p.R326Q. In addition, genetic analysis for Dravet syndrome showed the presence of heterozygous disease-causing mutation SCN1A NM_001165963.1:c.4494delC; NP_001159435.1:p.F1499Lfs*2. CONCLUSIONS The differentiation between Dravet syndrome and β-ureidopropionase deficiency is clinically challenging since both conditions share overlapping clinical features. The detection of urine β-ureidoisobutyric and β-ureidopropionic acids using NMR or GC-MS is helpful in laboratory diagnosis of β-ureidopropionase deficiency. The disease-causing mutation, c.977G>A of β-ureidopropionase deficiency, is highly prevalent in Chinese population (allele frequency=1.7%); β-ureidopropionase deficiency screening test should be performed for any patients with unexplained neurological deficit, developmental delay or autism.
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Affiliation(s)
- Ching-Wan Lam
- Department of Pathology, The University of Hong Kong, Hong Kong, China.
| | - Chun-Yiu Law
- Department of Pathology, The University of Hong Kong, Hong Kong, China
| | - Ka-Fei Leung
- Department of Pathology, The University of Hong Kong, Hong Kong, China
| | - Chi-Kong Lai
- Department of Pathology, Princess Margaret Hospital, Hong Kong, China
| | | | - Bosco Chan
- Department of Paediatrics and Adolescent Medicine, Princess Margaret Hospital, Hong Kong, China
| | - Kwok-Yin Chan
- Department of Paediatrics and Adolescent Medicine, Princess Margaret Hospital, Hong Kong, China
| | - Yuet-ping Yuen
- Department of Pathology, Princess Margaret Hospital, Hong Kong, China
| | - Chloe Miu Mak
- Department of Pathology, Princess Margaret Hospital, Hong Kong, China
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Law CY, Lam CW, Ching CK, Yau KCE, Ho TW, Lai CK, Mak CM. NMR-based urinalysis for beta-ketothiolase deficiency. Clin Chim Acta 2015; 438:222-5. [DOI: 10.1016/j.cca.2014.08.041] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Revised: 08/28/2014] [Accepted: 08/29/2014] [Indexed: 12/29/2022]
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Lam CW, Law CY, To KKW, Cheung SKK, Lee KC, Sze KH, Leung KF, Yuen KY. NMR-based metabolomic urinalysis: A rapid screening test for urinary tract infection. Clin Chim Acta 2014; 436:217-23. [DOI: 10.1016/j.cca.2014.05.014] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Revised: 05/06/2014] [Accepted: 05/15/2014] [Indexed: 02/01/2023]
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Lam CW, Law CY. Untargeted mass spectrometry-based metabolomic profiling of pleural effusions: fatty acids as novel cancer biomarkers for malignant pleural effusions. J Proteome Res 2014; 13:4040-6. [PMID: 25117182 DOI: 10.1021/pr5003774] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Untargeted mass spectrometry-based metabolomic profiling is a powerful analytical method used for broad-spectrum identification and quantification of metabolites in biofluids in human health and disease states. In this study, we exploit metabolomic profiling for cancer biomarker discovery for diagnosis of malignant pleural effusions. We envisage the result will be clinically useful since currently there are no cancer biomarkers that are accurate enough for the diagnosis of malignant pleural effusions. Metabolomes of 32 malignant pleural effusions from lung cancer patients and 18 benign effusions from patients with pulmonary tuberculosis were analyzed using reversed-phase liquid chromatography tandem mass spectrometry (LC-MS/MS) using AB SCIEX TripleTOF 5600. MS spectra were analyzed using XCMS, PeakView, and LipidView. Metabolome-Wide Association Study (MWAS) was performed by Receiver Operating Characteristic Curve Explorer and Tester (ROCCET). Insignificant markers were filtered out using a metabolome-wide significance level (MWSL) with p-value < 2 × 10(-5) for t test. Only compounds in Human Metabolome Database (HMDB) will be used as cancer biomarkers. ROCCET analysis of ESI positive and negative MS spectra revealed free fatty acid (FFA) 18:1 (oleic acid) had the largest area-under-ROC of 0.96 (95% CI = 0.87-1.00) in malignant pleural effusions. Using a ratio of FFA 18:1-to-ceramide (d18:1/16:0), the area-under-ROC was further increased to 0.99 (95% CI = 0.91-1.00) with sensitivity 93.8% and specificity 100.0%. Using untargeted metabolomic profiling, the diagnostic cancer biomarker with the largest area-under-ROC can be determined objectively. This lipogenic phenotype could be explained by overexpression of fatty acid synthase (FASN) in cancer cells. The diagnostic performance of FFA 18:1-to-ceramide (d18:1/16:0) ratio supports its use for diagnosis of malignant pleural effusions.
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Affiliation(s)
- Ching-Wan Lam
- Department of Pathology, The University of Hong Kong , Hong Kong, China
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Lam CW, Law CY, Sze KH, To KKW. Quantitative metabolomics of urine for rapid etiological diagnosis of urinary tract infection: evaluation of a microbial-mammalian co-metabolite as a diagnostic biomarker. Clin Chim Acta 2014; 438:24-8. [PMID: 25108210 DOI: 10.1016/j.cca.2014.07.038] [Citation(s) in RCA: 21] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Revised: 07/26/2014] [Accepted: 07/28/2014] [Indexed: 11/26/2022]
Abstract
BACKGROUND We have previously reported a NMR-based urinalysis for the screening of urinary tract infection (UTI) with high accuracy and reproducibility. Urinary acetic acid per creatinine was found to be a diagnostic marker of bacterial UTI with an area-under-receiver operating characteristic (ROC) curve of 0.97. In addition, we identified trimethylamine (TMA) as a human-microbial marker of Escherichia coli (EC)-associated UTI. Here, we evaluate the clinical application of NMR-based urinalysis in aiding the etiological diagnosis of bacterial UTI. METHODS Proton NMR spectroscopy was acquired using a Bruker 600MHz spectroscopy for 88 urine samples from patients with bacterial UTI, confirmed by urine culture. The spectra were analyzed using orthogonal partial least squares-discriminant analysis (OPLS-DA). ROC curve analysis was performed after the quantitation of the urine metabolites. RESULTS The TMA/creatinine (mmol/mmol) level was determined to be a specific marker for EC-associated UTI. It has an area-under-ROC=0.85 (95% confidence interval: 0.75-0.91). For the etiological diagnosis, the cutoff for 97.0% specificity was at 0.0117mmol/mmol creatinine for EC-associated UTI with a sensitivity of 66.7%. The mean of TMA/creatinine of EC is 21-fold that of non-EC. CONCLUSIONS The co-metabolism of TMA by EC and human cells makes TMA an ideal urine biomarker for UTI. The presence of TMA in a freshly collected sample eliminates the possibility of contamination of urine by bacteria during the collection process resulting in a positive bacterial culture result. We envisage the NMR-based urinalysis of urinary TMA that can be a useful method for the etiological diagnosis of EC-associated UTI.
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Affiliation(s)
- Ching-Wan Lam
- Department of Pathology, Queen Mary Hospital, The University of Hong Kong, Hong Kong, China.
| | - Chun-Yiu Law
- Department of Pathology, Queen Mary Hospital, The University of Hong Kong, Hong Kong, China
| | - Kong-Hung Sze
- Research Centre of Infection and Immunology, Hong Kong, China; State Key Laboratory for Emerging Infectious Diseases, Hong Kong, China; Department of Microbiology, The University of Hong Kong, Hong Kong, China
| | - Kelvin Kai-Wang To
- Research Centre of Infection and Immunology, Hong Kong, China; State Key Laboratory for Emerging Infectious Diseases, Hong Kong, China; Department of Microbiology, The University of Hong Kong, Hong Kong, China
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Lam CW, Law CY. Pleural Effusion Lipoproteins Measured by NMR Spectroscopy for Diagnosis of Exudative Pleural Effusions: A Novel Tool for Pore-Size Estimation. J Proteome Res 2014; 13:4104-12. [DOI: 10.1021/pr5004856] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ching-Wan Lam
- Department of Pathology, The University of Hong Kong, Pokfulam Road, Hong Kong, China
| | - Chun-Yiu Law
- Department of Pathology, The University of Hong Kong, Pokfulam Road, Hong Kong, China
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Pan NY, Law CY, Tsang WK, Lee KL, Wong KC, Tam KF. Giant Cell Tumour of the Axial Skeleton: Report of Four Cases. Hong Kong J Radiol 2014. [DOI: 10.12809/hkjr1411064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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Mak CM, Siu WK, Law CY, Wong CK, Lee HK, Yeung S, Sham CO, Tse K, Lee HHC, Chen SPL, Ching CK, Au CK, Poon WT, Lam CW, Kwong NS, Chan AYW. Electronic chemical pathology consultation service and dried blood spot metabolic screening in hospital patients. J Clin Pathol 2012; 65:1141-5. [PMID: 22888119 DOI: 10.1136/jclinpath-2012-200837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AIM Inborn errors of metabolism (IEM) are an unpopular and difficult subject and most clinicians are unfamiliar with them. Although chemical pathologists have a long-standing practice in advising test strategy and result interpretation especially from primary care, such consultations are usually informal, unstructured and those related to IEM are infrequently requested. This study aims to provide a formal electronic consultation service and to apply tandem mass spectrometry-based dried blood spot metabolic screening (DBSM) as a rapid first-line test for patients suspected of IEM. METHODS DBSM and a chemical pathology consultation were ordered through the hospital computer terminals. DBSM detected 29 metabolic disorders. The clinical data and metabolic results for the 12-month period were reviewed. RESULTS There were 279 consultations of which 209 were initiated by paediatricians and 70 by adult physicians. The main reasons for consultation were developmental delay, neurological abnormalities, unexplained biochemical abnormalities and monitoring of patients with IEM. There were 158 DBSM requests. One positive case of isovaleric acidaemia was detected. CONCLUSIONS All high-risk paediatric patients should have a DBSM and a timely electronic chemical pathology consultation as a rapid and cost-effective first-line screening. Provision of a visible, accessible and helpful consultation service enables professional reimbursement.
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Affiliation(s)
- Chloe Miu Mak
- Chemical Pathology Laboratory, Department of Pathology, Princess Margaret Hospital, Hong Kong SAR, China.
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Hung CN, Poon WT, Lee CY, Law CY, Chan AYW. A case of early-onset obesity, hypocortisolism, and skin pigmentation problem due to a novel homozygous mutation in the proopiomelanocortin (POMC) gene in an Indian boy. J Pediatr Endocrinol Metab 2012; 25:175-9. [PMID: 22570972 DOI: 10.1515/jpem-2011-0437] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Proopiomelanocortin (POMC) is the polypeptide precursor of several biologically active melanocortin peptides that have important roles in the regulation of food intake and energy homeostasis, adrenal steroidogenesis, melanocyte stimulation, and immune modulation. Mutation of the POMC gene has been associated with adrenal insufficiency, early-onset obesity, and red hair pigmentation. We describe an Indian boy with secondary hypocortisolism, hyperphagia, early-onset obesity, and skin pigmentation problem. Genetics analysis revealed a novel homozygous mutation in the POMC gene (p.Arg86Term). The boy also had central hypothyroidism in addition to the secondary hypocortisolism. Genetics analysis for the POMC gene should be considered in patients with secondary hypocortisolism, early-onset obesity, and pigmentary problems.
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Affiliation(s)
- Ching-Ngar Hung
- Department of Paediatrics and Adolescent Medicine, Princess Margaret Hospital, Hong Kong SAR, China.
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Mak CM, Chan KY, Yau EKC, Chen SPL, Siu WK, Law CY, Lam CW, Chan AYW. Genetic diagnosis of severe myoclonic epilepsy of infancy (Dravet syndrome) with SCN1A mutations in the Hong Kong Chinese patients. Hong Kong Med J 2011; 17:500-502. [PMID: 22147323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023] Open
Abstract
Epilepsy is a clinically and genetically heterogeneous group of disorders. The advent of molecular genetics brings unprecedented advancement in diagnostic molecular pathology and reduces over-reliance on traditional clinical classification. Severe myoclonic epilepsy of infancy or Dravet syndrome is a catastrophic infantile-onset epilepsy. We report two unrelated Hong Kong Chinese patients with this condition presenting with febrile seizures, epilepsy with different semiologies, psychomotor retardation, and recurrent status epilepticus. Two different mutations were characterised, viz NM_001165963.1: c.680T>G; NP_001159435.1: p.I227S and NM_001165963.1: c.3953T>G; NP_001159435.1: p.L1318R (novel). Genetic characterisation conveys a definitive diagnosis and is important from the perspective of selecting anti-epileptic drug therapy and genetic counselling.
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Affiliation(s)
- Chloe M Mak
- Kowloon West Cluster Laboratory Genetic Service, Chemical Pathology Laboratory, Department of Pathology, Princess Margaret Hospital, Laichikok, Hong Kong.
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Mak CM, Ko CH, Lam CW, Lau WL, Siu WK, Chen SPL, Law CY, Lai CK, Yu CM, Chan AYW. Phenylketonuria in Hong Kong Chinese: a call for hyperphenylalaninemia newborn screening in the Special Administrative Region, China. Chin Med J (Engl) 2011; 124:2556-2558. [PMID: 21933604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023] Open
Abstract
Hyperphenylalaninemia is one of the commonest inborn errors of metabolism affecting approximately 1 in 15,000 livebirths. Among Chinese, BH4 deficiency leading to hyperphenylalaninemia is much commoner than in Caucasians. Exact diagnosis is important for the treatment and genetic counseling. In 2000, newborn screening for phenylketonuria is mandatory by law in China throughout the whole country. However, it is not yet included in the newborn screening program of the Hong Kong Special Administrative Region, China. Published data on hyperphenylalaninemia among HongKong Chinese are largely lacking. We report a 1-year-old Hong Kong Chinese girl with severe 6-pyruvoyl-tetrahydropterin synthase (PTPS) deficiency. The patient presented with infantile hypotonia and was misdiagnosed as cerebral palsy. She had very mild hyperphenylalaninemia (95 μmol/L), significantly high phenylalnine-to-tyrosine ratio (3.1), and elevated prolactin of 1109 mIU/L. Genetic analysis confirmed a homozygous known disease-causing mutation PTS NM_000317.1:c.259C>T; NP_000308.1: p.P87S in the proband. In our local experience, while the estimated prevalence of hyperphenylalaninemia due to PTPS deficiency was reported to be 1 in 29,542 live births, not a single case of phenylalanine hydroxylase deficiency has been reported. Furthermore, there is a general lack of awareness of inherited metabolic diseases in the community as well as among the medical professionals. Very often, a low index of clinical suspicion will lead to delay in diagnosis, multiple unnecessary and costly investigations, prolonged morbidity and anxiety to the family affected. We strongly recommend that expanded newborn screening for hyperphenylalaninemia should be implemented for every baby born in the Hong Kong Special Administrative Region, China.
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Affiliation(s)
- Chloe Miu Mak
- Kowloon West Cluster Laboratory Genetic Service, Chemical Pathology Laboratory, Department of Pathology, Princess Margaret Hospital, Hong Kong, China
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Lee HCH, Mak CM, Lam CW, Yuen YP, Chan AOK, Shek CC, Siu TS, Lai CK, Ching CK, Siu WK, Chen SPL, Law CY, Tai HLM, Tam S, Chan AYW. Analysis of inborn errors of metabolism: disease spectrum for expanded newborn screening in Hong Kong. Chin Med J (Engl) 2011; 124:983-989. [PMID: 21542954] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023] Open
Abstract
BACKGROUND Data of classical inborn errors of metabolism (IEM) of amino acids, organic acids and fatty acid oxidation are largely lacking in Hong Kong, where mass spectrometry-based expanded newborn screening for IEM has not been initiated. The current study aimed to evaluate the approximate incidence, spectrum and other characteristics of classical IEM in Hong Kong, which would be important in developing an expanded newborn screening program for the local area. METHODS The laboratory records of plasma amino acids, plasma acylcarnitines and urine organic acids analyses from year 2005 to 2009 inclusive in three regional chemical pathology laboratories providing biochemical and genetic diagnostic services for IEM were retrospectively reviewed. RESULTS Among the cohort, 43 patients were diagnosed of IEM, including 30 cases (69%) of amino acidemias (predominantly citrin deficiency, hyperphenylalaninemia due to 6-pyruvoyl-tetrahydropterin synthase deficiency and tyrosinemia type I), 5 cases (12%) of organic acidemias (predominantly holocarboxylase synthetase deficiency) and 8 cases (19%) of fatty acid oxidation defects (predominantly carnitine-acylcarnitine translocase deficiency). The incidence of classical IEM in Hong Kong was roughly estimated to be at least 1 case per 4122 lives births, or 0.243 cases per 1000 live births. This incidence is similar to those reported worldwide, including the mainland of China. The estimated incidence of hyperphenylalaninemia was 1 in 29 542 live births. CONCLUSIONS Our data indicate that it is indisputable for the introduction of expanded newborn screening program in Hong Kong. Since Hong Kong is a metropolitan city, a comprehensive expanded newborn screening program and referral system should be available to serve the neonates born in the area.
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Affiliation(s)
- Han-Chih Hencher Lee
- Chemical Pathology Laboratory, Department of Pathology, Princess Margaret Hospital, Hong Kong SAR, China
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Lau KC, Lam CW, Law CY, Lai ST, Tsang TY, Siu CWK, To WK, Leung KF, Mak CM, Poon WT, Chan PKS, Chan YW. Non-invasive screening of HLA-DPA1 and HLA-DPB1 alleles for persistent hepatitis B virus infection: susceptibility for vertical transmission and toward a personalized approach for vaccination and treatment. Clin Chim Acta 2011; 412:952-7. [PMID: 21310144 DOI: 10.1016/j.cca.2011.01.030] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2010] [Revised: 01/24/2011] [Accepted: 01/24/2011] [Indexed: 12/17/2022]
Abstract
BACKGROUND Polymorphisms in the major histocompatibility complex (MHC) and non-MHC genes were recently reported to be associated with persistent hepatitis B virus (HBV) infection and host response to hepatitis B vaccine in Asian populations. We aimed to confirm the associations in Chinese population and develop a non-invasive screening method for the risk loci. METHODS We genotyped 2 risk alleles on the MHC loci, HLA-DPA1 (rs3077) and HLA-DPB1 (rs9277535), and 1 risk allele near a non-MHC gene, FOXP1 (rs6789153) using high-resolution melting curve analysis. With minimal processing steps and time, salivary DNA was extracted with a modified protocol of a blood kit. We compared the genotyping fidelity between peripheral blood DNA and salivary DNA. RESULTS Both rs3077 and rs9277535, but not rs6789153, are significantly associated with CHB in Chinese population (p-value<0.001). High genotype concordance between different sources of genomic DNA was obtained. CONCLUSIONS Genotyping salivary DNA using our modified methods provides a non-invasive fast screening for host susceptibility loci. The transmission mechanism of hepatitis B can now be modified by adding genetic susceptibility to the traditional vertical transmission model of hepatitis B.
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Affiliation(s)
- Kin-Chong Lau
- Department of Pathology, The University of Hong Kong, Queen Mary Hospital, Hong Kong, China
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