Congenital insensitivity to pain is a rare human condition in which affected individuals do not experience pain throughout their lives. This study aimed to identify the molecular etiology of congenital insensitivity to pain in two Thai patients. Clinical, radiographic, histopathologic, immunohistochemical, and molecular studies were performed. Patients were found to have congenital insensitivity to pain, self-mutilation, acro-osteolysis, cornea scars, reduced temperature sensation, tooth agenesis, root maldevelopment, and underdeveloped maxilla and mandible. The skin biopsies revealed fewer axons, decreased vimentin expression, and absent neurofilament expression, indicating lack of dermal nerves. Whole exome and Sanger sequencing identified a rare homozygous variant c.4039C>T; p.Arg1347Cys in the plakin domain of Plec, a cytolinker protein. This p.Arg1347Cys variant is in the spectrin repeat 9 region of the plakin domain, a region not previously found to harbor pathogenic missense variants in other plectinopathies. The substitution with a cysteine is expected to decrease the stability of the spectrin repeat 9 unit of the plakin domain. Whole mount in situ hybridization and an immunohistochemical study suggested that Plec is important for the development of maxilla and mandible, cornea, and distal phalanges. Additionally, the presence of dental anomalies in these patients further supports the potential involvement of Plec in tooth development. This is the first report showing the association between the Plec variant and congenital insensitivity to pain in humans.

BACKGROUND:Primary carnitine deficiency (PCD) is screened by expanded newborn screening (NBS) using tandem mass spectrometry (MS/MS) that can detect both affected neonates and mothers. This study aimed to delineate the clinical, biochemical, and molecular findings of Thai PCD patients.METHODS:Expanded NBS using MS/MS was implemented in Bangkok and 146,757 neonates were screened between 2014 and 2018. PCD was screened by low free carnitine (C0) levels in dried blood spots. Plasma C0 levels and C0 clearance values were measured in neonates and their mothers with positive screening results. Clinically diagnosed cases were described. The coding regions and intron-exon boundaries of the SLC22A5 gene were sequenced in all cases with low plasma C0 levels.RESULTS:There were 14 cases with confirmed PCD: two clinically diagnosed cases, and 12 cases identified through NBS including five newborns, six mothers, and one older sibling. Thus, the incidence of PCD in neonates was 1:29,351. All affected neonates and mothers were asymptomatic except one mother with dilated cardiomyopathy. SLC22A5 gene sequencing identified biallelic causative variants in all cases, comprising 10 different variants of which four were novel. c.51C > G (p.Phe17Leu) and c.760C > T (p.Arg254Ter) were the most prevalent variants in this study. Cases with significant clinical features tended to have higher C0 clearance values.CONCLUSIONS:Primary carnitine deficiency is a common inherited metabolic disorder (IMD) in Thailand. Our findings broaden the spectrum of SLC22A5 variants. The future national NBS program will shed more light on PCD and other IMDs in Thailand.

Phenylketonuria (PKU) is an autosomal recessive amino acid metabolism disorder caused by variants in the gene encoding phenylalanine hydroxylase (PAH; EC1.14.16.1). This study aimed to assess the specific heterogeneity of PAH variants found in Thai population as well as evaluate enzyme activity and expression of novel variants. PAH gene from 13 patients was analyzed by PCR amplification and direct Sanger-sequencing of 13 exons of the coding region. The novel variants were transiently transfected in COS-7 cells for functional verification. Eleven different PAH variants were identified: all pathogenic variants were missense variants, of which the most frequent variant was p.R169L, accounting for 24% (6/25) of all identified alleles. Two novel variants p.R169L and p.Y317N and previously reported variants with mutated residues at the same positions (p.R169H and p.Y317H) were expressed in COS-7 cells. These showed mildly impaired residual activity levels (42.3–63.1% of wild type), while the protein levels were well expressed (82.8–110%), except for p.R169L, which showed decreased protein expression of 55.7% compared to the wild type enzyme. All subjects with p.R169L identified in at least one of pathogenic alleles (one case is homozygous) had a metabolic phenotype of mild hyperphenylalaninemia (HPA). Our data has expanded the information on the genetic heterogeneity of Thai patients with PAH deficiency. This finding emphasizes the importance of genotyping in patients with HPA, and in vitro studies can provide additional information for prediction of phenotype.

Putting together the reports in this issue that come from a representation of the different countries in Asia presents an opportunity to share the unique story of the Asia Pacific Society of Human Genetics (APSHG), which has provided the authors of many of these articles. This paper, authored by the Past Presidents of the Society, shares glimpses of how medical genetics activities were first organized in the Asia Pacific region and provides interesting corollaries on how under-developed and developing countries in this part of the world had developed a unique network for exchange and sharing of expertise and resources. Although APSHG was formally registered as a Society in Singapore in 2006, the Society has its origins as far back as in the 1990s with members from different countries meeting informally, exchanging ideas, and collaborating. This treatise documents the story of the experiences of the Society and hopes it will provide inspiration on how members of a genetics community can foster and build a thriving environment to promote this field.

Background: Lysosomal storage disorders (LSDs) are a large group of inherited metabolic diseases which mostly involve the defects of acid hydrolases, resulting in impaired substrate degradation in lysosome. The progressive accumulation of undegraded metabolites causes cell and tissue dysfunction, leading to multi-systemic pathology. The LSDs have yet to be well-studied in Thailand, but more work on mutation analysis has been carried out in the last 10 years, including work from our laboratory. In collaboration with pediatricians from Siriraj Hospital, Ramathibodi Hospital and Queen Sirikit National Institute of Child Health we are focusing on biochemical research and molecular aspects of LSDs. Methods: Blood sample from more than 50 patients who clinically diagnosed to be LDSs, including Mucopolysaccharidosis (MPS), Gaucher disease, Pompe disease, and Fabry disease were characterized in term of the defective enzymes and mutational analysis. Results: All samples were enzymatic assay and mutations resulting in defective enzymes were detected, 40 cases were confirmed having an MPS, 10 cases were Gaucher disease, 3 cases were Pompe disease and 4 cases were Fabry disease. Mutations were found including splicing variants, crossing-over, nonsense and missense mutations, several of them were first described. Conclusions: The reported data provide information for the molecular aspects of mutations causing LSDs in Thai population that could help to plan for genetic counseling as well as useful for therapies available for most of the cases diagnosis or target treatment for specific mutations.

Background: Multiple acyl-CoA dehydrogenase deficiency (MADD) is caused by mutations in the alpha (ETFA) and beta (ETFB) subunits of electron transfer flavoprotein, and electron transfer flavoprotein dehydrogenase (ETFDH) which involves in the mitochondrial electron transport from acyl CoAs to ubiquinone. Thus the mitochondrial oxidations of glutaryl CoA and branched-chain organic acids, and beta-oxidation of fatty acids are impaired. The phenotype is classified into neonatal-onset (severe), infantile-onset (intermediate), and late-onset (myopathic) forms. Methods: We retrospectively reviewed the clinical features of patients with MADD who were diagnosed by urine organic acids or blood acylcarnitine analysis at Department of Pediatrics, Faculty of Medicine Siriraj Hospital. Molecular analysis was performed in biochemically confirmed cases. Results: Among 11 Thai patients with MADD, the most common form is the late-onset (8 cases), 2 cases with the neonatal-onset form, and 1 case with the infantileonset form. All cases with the late-onset form presented with muscle symptoms characterized by neck weakness. Muscle biopsy showed lipid myopathy. Some of them had hypoglycemia and cardiomyopathy. Interestingly, three cases had excessive weight loss. All late-onset cases were responsive to riboflavin treatment. Two patients with neonatal onset presented with hypoglycemia, acidosis, hyperammonemia, and sweaty feet odor since 1 day of age. Hypospadias was noted in one case, and mild dysmorphic face in another. The 2 cases were fatal, and died in infancy. One case with probably intermediate form was identified by newborn screening, and only mild acidosis was noted at 7 days of age. Not all patients with the late-onset form showed the characteristic profiles in blood acylcarnitines and urine organic acids. The c.250G>A (p.A84T) mutation in the ETFDH gene is commonly found in our late-onset, riboflavin-responsive patients. Conclusions: We report a phenotypic spectrum of MADD in Thai population. The ETFDH mutations could predict the clinical phenotype and riboflavin responsiveness.

Background A pilot expanded newborn screening (NBS) program to detect inborn errors of metabolism (IEM) using tandem mass spectrometry (TMS) began at Siriraj Hospital, Bangkok, Thailand in May, 2014, with funding support from National Health Security Office (NSHO).

Background: Craniofacial anomalies (CFA) result from interruption of normal embryologic growth and differentiation of the face and skull, and can be classified in several groups, such as branchial arch syndromes, craniosynostosis, orofacial clefts, and encephalocele. Management of CFA requires multidisciplinary team. Cranio-maxillo-facial clinic at Siriraj hospital was founded more than 15 years, and consists of experts from multiple medical and surgical specialties, such as plastic surgeon, neurosurgeon, ophthalmologist, otolaryngologist, orthodontist, and clinical geneticist.

Background: Genetic skeletal dysplasias are a heterogeneous group of disorders associated with abnormalities in the size and shape of the limbs, trunk, and/or skull that frequently result in disproportionate short stature. There are well over 100 distinct skeletal dysplasias that have been classified primarily on the basis of their clinical or radiographic characteristics.

Isolated methylmalonic acidemia (MMA) is an autosomal recessive, inherited disorder that results from either a mut defect of the methylmalonyl-CoA mutase apoenzyme (MCM, the product of the MUT gene) or a cbl defect in the synthesis of its cofactor, adenosylcobalamin (AdoCbl). In this study, biochemical and mutational analyses of three patients clinically diagnosed with MMA were performed. No MCM activity was detected in leukocyte extracts of two patients, while high MCM activity was found in the other, suggesting mut 0 and cbl defects, respectively. A novel (c.IVS6 -3 to -8delCTTTTT, p.K444_L445insFC*) and two known mutations in the MUT gene and one novel (c.227_36delGACCCAAAGA, p.R76Mfs*14) mutation in the MMAB gene were identified. In addition, MCM immunoblot analysis of leukocyte extract samples of these three patients and eight patients previously reported by our group, as well as their parents, showed a good correlation between the MCM protein and activity levels. Patients with mut 0 defective subtypes lacked MCM activity and had no MCM band, while patients carrying the cbl defects had high MCM activity levels and an intense MCM band at about 83 kDa, in comparison to those in their parents. These data expand the mutation spectrum of MMA deficiency. In addition, the examination of MCM protein level may be used as an alternative technique to determine the mut 0 and cbl defective subgroups.

BackgroundInborn errors of metabolism (IEM) are a rare group of genetic diseases which can lead to several serious long-term complications in newborns. In order to address these issues as early as possible, a process called tandem mass spectrometry (MS/MS) can be used as it allows for rapid and simultaneous detection of the diseases. This analysis was performed to determine whether newborn screening by MS/MS is cost-effective in Thailand.MethodA cost-utility analysis comprising a decision-tree and Markov model was used to estimate the cost in Thai baht (THB) and health outcomes in life-years (LYs) and quality-adjusted life year (QALYs) presented as an incremental cost-effectiveness ratio (ICER). The results were also adjusted to international dollars (I$) using purchasing power parities (PPP) (1 I$ = 17.79 THB for the year 2013). The comparisons were between 1) an expanded neonatal screening programme using MS/MS screening for six prioritised diseases: phenylketonuria (PKU); isovaleric acidemia (IVA); methylmalonic acidemia (MMA); propionic acidemia (PA); maple syrup urine disease (MSUD); and multiple carboxylase deficiency (MCD); and 2) the current practice that is existing PKU screening. A comparison of the outcome and cost of treatment before and after clinical presentations were also analysed to illustrate the potential benefit of early treatment for affected children. A budget impact analysis was conducted to illustrate the cost of implementing the programme for 10 years.ResultsThe ICER of neonatal screening using MS/MS amounted to 1,043,331 THB per QALY gained ( 58,647 I$ per QALY gained). The potential benefits of early detection compared with late detection yielded significant results for PKU, IVA, MSUD, and MCD patients. The budget impact analysis indicated that the implementation cost of the programme was expected at approximately 2,700 million THB ( 152 million I$) over 10 years.ConclusionAt the current ceiling threshold, neonatal screening using MS/MS in the Thai context is not cost-effective. However, the treatment of patients who were detected early for PKU, IVA, MSUD, and MCD, are considered favourable. The budget impact analysis suggests that the implementation of the programme will incur considerable expenses under limited resources. A long-term epidemiological study on the incidence of IEM in Thailand is strongly recommended to ascertain the magnitude of problem.

Thailand Task Force on Birth Defects and Disabilities was first organized in 2008. From 2011-2014, Birth Defects Association (Thailand) received funding from ThaiHealth Promotion Foundation and the outcomes are: (I) pilot program on Birth Defects Registry (BDR), both on case record form (CRF) and later developed into BDR Online; in 22 out of 77 provinces; (II) eleven health districts model in 11 provinces focus on holistic approach on prevention and care of 5 chosen disorders-down syndrome (DS), neural tube defects (NTD), cleft lip/palate (CL/P), limb anomalies (LA) and duchenne muscular dystrophy (DMD); (III) manuals and care map for five chosen birth defects for provincial and community hospitals completed; (IV) memorandum of understanding (MOU) was signed in 2012 between four ministries (Health, Education, Social Welfare and Human Security) and interior two organizations (National Health Security Office and ThaiHealth Promotion Foundation) including Birth Defects Association (Thailand); (V) national network was developed consisting of expert paediatricians and obstetricians from eight medical institutions including Queen Sirikit National Children Center in Bangkok; (VI) Country Action Plan’ initiated by Department of Medical Services, Ministry of Public Health; (VII) strategic map, master plan and care map developed; (VIII) systematic approach including working with policymakers and stakeholders at country, provincial and community level. From 2015-2017, Birth Defects Association (Thailand) continues to receive fundings from ThaiHealth Promotion Foundation focusing on three objectives: (I) moving forward towards national policy; (II) strengthening the holistic approach in 26 health districts model including one in Bangkok metropolitan area; (III) raising awareness in prevention of birth defects using folate supplementation in women of child bearing age with emphasis on girls in secondary schools.

BACKGROUND:Mitochondrial fatty acid oxidation (FAO) disorders are among the causes of acute encephalopathy- or myopathy-like illness. Carnitine-acylcarnitine translocase (CACT) deficiency is a rare FAO disorder, which represent an energy production insufficiency during prolonged fasting, febrile illness, or increased muscular activity. CACT deficiency is caused by mutations of the SLC25A20 gene. Most patients developed severe metabolic decompensation in the neonatal period and died in infancy despite aggressive treatment. PATIENTS AND METHODS:We herein report the clinical findings of two unrelated cases of CACT deficiency with mutation confirmation, and in vitro bezafibrate responses using in vitro probe acylcarnitine (IVP) assay. Patients 1 and 2 are products of nonconsanguineous parents. Both patients developed cardiac arrest at day 3 of life but survived the initial events. Their blood chemistry revealed hypoglycemia and metabolic acidosis. The acylcarnitine profiles in both patients demonstrated increased long-chain acylcarnitines, suggesting CACT or carnitine palmitoyltransferase-2 (CPT2) deficiency. RESULTS:The mutation analysis identified homozygous IVS2-10T>G in the SLC25A20 gene in both patients, confirming the diagnosis of CACT deficiency. The IVP assay revealed increased C16, C16:1, but decreased C2 with improvement by bezafibrate in the cultured fibroblasts. The short-term clinical trial of bezafibrate in Patient 1 did not show clinical improvement, and died after starting the trial for 6 months. CONCLUSION:This splicing mutation has been identified in other Asian populations indicating a possible founder effect. IVP assay of cultured fibroblasts could determine a response to bezafibrate treatment. A long-term clinical trial of more enrolled patients is required for evaluation of this therapy.

Background: Propionic acidemia (PA) is caused by a deficiency of propionyl CoA carboxylase. A characteristic urine organic acid profile includes 3-hydroxypropionate, methylcitrate, tiglylglycine, and propionylglycine. The diagnosis of PA is confirmed by detection of mutations in the PCCA or PCCB genes. We herein report the clinical and molecular findings of four Thai patients with PA.Methods: Clinical findings of four Thai patients with PA were retrospectively reviewed. Urine organic acids were analyzed by gas chromatography-mass spectrometry. PCR-sequencing analyses of encoding exons and intron/exon boundaries of the PCCA and PCCB genes were performed.Results: All patients had neonatal onset of PA. One patient died of cardiomyopathy, and another one of pneumonia and metabolic decompensation. The remainder experienced significant neurocognitive impairment. Mutation analysis of the PCCA gene identified homozygous c.1284+1G>A in patient 1, c.230G>A (p.R77Q) and c.1855C>T (p.R619X) in patient 2, homozygous c.2125T>C (p.S709P) in patient 3, and only one mutant allele, c.231+1G>T in patient 4. No PCCB mutation was identified. Four mutations including c.230G>A, c.231+1G>T, c.1855C>T, and c.2125T>C have not been reported previously.Conclusions: The clinical and molecular study of these Thai patients provided additional knowledge of the genotype and phenotype characteristics of PA. The results of the study suggested that PCCA mutations in Asian populations were distinct from those of other populations.

This paper reports on the workshop ‘Genetic Counseling/Consultations in South-East Asia’ at the 10th Asia Pacific Conference on Human Genetics in Kuala Lumpur, Malaysia, in December 2012. The workshop brought together professionals and language/communication scholars from South-East Asia, and the UK. The workshop aimed at addressing culture- and context-specific genetic counseling/consultation practices in South-East Asia. As a way of contextualizing genetic counseling/consultation in South-East Asia, we first offer an overview of communication-oriented research generally, drawing attention to consultation and counseling as part of a communicative continuum with distinctive interactional features. We then provide examples of genetic counseling/consultation research in Hong Kong. As other countries in South-East Asia have not yet embarked on communication-oriented empirical research, we report on the current practices of genetic counseling/consultation in these countries in order to identify similarities and differences as well as key obstacles that could be addressed through future research. Three issues emerged as ‘problematic’: language, religion and culture. We suggest that communication-oriented research can provide a starting point for evidence-based reflections on how to incorporate a counseling mentality in genetic consultation. To conclude, we discuss the need for creating a platform for targeted training of genetic counselors based on communication-oriented research findings.

Isolated methylmalonic acidemia (MMA) is a genetically heterogeneous organic acid disorder caused by either deficiency of the enzyme methylmalonyl-CoA mutase (MCM), or a defect in the biosynthesis of its cofactor, adenosyl-cobalamin (AdoCbl). Herein, we report and review the genotypes and phenotypes of 14 Thai patients with isolated MMA. Between 1997 and 2011, we identified 6 mut patients, 2 cblA patients, and 6 cblB patients. The mut and cblB patients had relatively severe phenotypes compared to relatively mild phenotypes of the cblA patients. The MUT and MMAB genotypes were also correlated to the severity of the phenotypes. Three mutations in the MUT gene: c.788G>T (p.G263V), c.809_812dupGGGC (p.D272Gfs*2), and c.1426C>T (p.Q476*); one mutation in the MMAA gene: c.292A>G (p.R98G); and three mutations in the MMAB gene: c.682delG (p.A228Pfs*2), c.435delC (p.F145Lfs*69), and c.585-1G>A, have not been previously reported. RT-PCR analysis of a common intron 6 polymorphism (c.520-159C>T) of the MMAB gene revealed that it correlates to deep intronic exonization leading to premature termination of the open reading frame. This could decrease the ATP:cobalamin adenosyltransferase (ATR) activity resulting in abnormal phenotypes if found in a compound heterozygous state with a null mutation. We confirm the genotype–phenotype correlation of isolated MMA in the study population, and identified a new molecular basis of the cblB disorder.

Introduction: Mucopolysaccharidosis (MPS) type VI (Maroteaux-Lamy syndrome) is a clinically heterogeneous lysosomal storage disorder. It presents significant diagnostic and treatment challenges due to the rarity of the disease and complexity of the phenotype. As information about MPS VI in Asia-Pacific countries is limited, a survey was conducted to assess current practices for diagnosis and management of MPS VI in this region. The participants were selected based on their experience in diagnosing and managing MPS patients.Methods: The survey comprised 29 structured quantitative or qualitative questions. Follow-up consultations were undertaken to discuss the data further.Results: Thirteen physicians from eight countries or regions (Australia, China, Hong Kong, Japan, Malaysia, Philippines, Taiwan and Thailand) were surveyed. At the time of the survey twenty-two patients with MPS VI were directly treated by the respondents and most (similar to 80%) had rapidly progressing disease. A wide range of medical specialists are involved in managing patients with MPS VI, the most common being orthopedic surgeons, pediatricians and geneticists. The availability/accessibility of diagnostic tools, therapies and national insurance coverage vary greatly across the countries/regions and, in some cases, between different regions within the same country. Currently, there are national MPS management groups in Australia and Japan. Australia, Taiwan and Hong Kong have local guidelines for managing MPS and local MPS registries are available in Australia, Taiwan, and Japan.Conclusions: This survey highlights differences in the diagnosis and management of MPS VI between Asia-Pacific countries/regions. Important barriers to advancing the identification, understanding and treatment of MPS VI include the paucity of epidemiological information, limited access to laboratory diagnostics and therapies, low disease awareness, and a lack of monitoring and treatment guidelines. There is a clear need to facilitate communications between physicians and establish regional or national disease registries, a multidisciplinary referral network, and a centralized diagnostic and management framework. (C) 2012 Elsevier Inc. All rights reserved.

Background: Amino acid disorders are a major group of inborn errors of metabolism (IEM) with variable clinical presentations. This study was aimed to provide the data of amino acid disorders detected in high-risk Thai patients referred to our metabolic lab from all over the country.Methods: From 2001 to 2009, we analyzed amino acids by HPLC in 1214 plasma and cerebrospinal fluid specimens. These specimens were obtained from patients with clinical suspicion of IEM or with positive newborn screening. The clinical data of the patients with confirmed diagnoses of amino acid disorders were also analyzed.Results: Fifty-eight patients were diagnosed with amino acid disorders, including 20 cases (34.5%) with maple syrup urine disease, 13 (22.4%) with phenylketonuria and hyperphenylalaninemia, 13 (22.4%) with nonketotic hyperglycinemia, 9 (15.5%) with urea cycle defects, 2 (3.4%) with classical homocystinuria, and 1 (1.7%) with ornithine aminotransferase deficiency. There was considerable delay in diagnoses which led to poor outcomes in most patients.Conclusion: The prevalence of amino acid disorders in Thailand is distinct from other countries. This will guide the selection of the prevalent IEM for the future expansion of newborn screening program in this country. (C) 2012 Elsevier B.V. All rights reserved.