Novel prenatally diagnosed compound heterozygous PXDN variants in fetal congenital primary aphakia and blepharophimosis.

OBJECTIVE: To precision survey a fetal congenital primary aphakia molecular etiology. CASE REPORT: A case of 42 years old pregnancy woman prenatal diagnostic examination by amniocentesis conducted at 17 weeks' gestation and demonstrated a normal female karyotype. Trio studies based on chromosome microarray analysis (CMA) and Sanger's genetic analysis did not detect a pathologic variant of the FOXE3 gene. Fetal congenital primary aphakia accompanied with microphthalmia detected by sonography in the second trimester (22 weeks). MRI indicated bilateral absence of the lenses, consistent with primary congenital aphakia. Due to the poor prognosis of congenital aphakia, the parents decided to terminate the fetus and provided consent for an autopsy. Pathological analysis revealed dysplasia of the anterior segment of both eyes. However, post fetal mortem extended trio whole exon sequencing (WES) and Sanger's genetic analysis identified compound heterozygous variants in the chromosomal location 2p25.3 in the PXDN gene. CONCLUSION: Extended whole exon sequencing is an important tool to study primary congenital aphakia.

Prediction of functional consequences of the five newly discovered G6PD variations in Taiwan.

Glucose-6-phosphate dehydrogenase deficiency (G6PD deficiency; OMIM #300908) is the most common inborn error disorders worldwide. While the G6PD is the key enzyme of removing oxidative stress in erythrocytes, the early diagnosis is utmost vital to prevent chronic and drug-, food- or infection-induced hemolytic anemia. The characterization of the mutations is also important for the subsequent genetic counseling, especially for female carrier with ambiguous enzyme activities and males with mild mutations. While multiplex SNaPshot assay and Sanger sequencing were performed on 500 G6PD deficient males, five newly discovered variations, namely c.187G > A (p.E63K), c.585G > C (p.Q195H), c.586A > T (p.I196F), c.743G > A (p.G248D), and c.1330G > A (p.V444I) were detected in the other six patients. These variants were previously named as the Pingtung, Tainan, Changhua, Chiayi, and Tainan-2 variants, respectively. The in silico analysis, as well as the prediction of the structure of the resultant mutant G6PD protein indicated that these five newly discovered variants might be disease causing mutations.

Applying a multiplexed primer extension method on dried blood spots increased the detection of carriers at risk of glucose-6-phosphate dehydrogenase deficiency in newborn screening program.

BACKGROUND: Patients with glucose-6-phosphate dehydrogenase deficiency might develop acute hemolytic anemia, chronic hemolytic anemia, and neonatal hyperbilirubinemia when exposed to high levels of oxidative stress. Severe hemolysis may occur in not only patients but also female carriers under certain conditions. However, 80%-85% of female carriers were undetected in an existing newborn screening program because of their wide-ranging levels of enzyme activity. METHODS: We developed a cost- and time-efficient multiplex SNaPshot assay using dried blood spots. RESULTS: By detecting 21 common mutations in Taiwan and Southeast Asia, the assay could determine 98.2% of the mutant alleles in our cohort of Taiwanese newborns. The 9 undetermined mutant alleles were consequently detected by Sanger sequencing, of which 5 unpublished variations-c.187G > A (Pingtung), c.585G > C (Tainan), c.586A > T (Changhua), c.743G > A (Chiayi), and c.1330G > A (Tainan-2)-were detected. Furthermore, 13% of mild mutations were missed in male infants whose enzyme levels at 6.1-7.0 U/gHb in the newborn screening program when set the cutoff value at 6.0 U/gHb. We therefore suggest increasing the cutoff value and applying the multiplex SNaPshot assay as the second tier for neonatal screening. CONCLUSIONS: Our approach could significantly increase the detection rate of male patients and female carriers with a reasonable cost and a reasonable number of clinic referrals.

Association between health behaviors and mood disorders among the elderly: a community-based cohort study.

BACKGROUND: According to a WHO report, nearly 15% of adults aged 60 and over suffer from a mental disorder, constituting 6.6% of the total disability for this age group. Taipei City faces rapid transformation towards an aging society, with the proportion of elderly in the total population rising from 12% in 2008 to 16% in 2016. The aim of this study is to identify the prevalence of mental disorders among the elderly in Taipei City and to elucidate risk factors contributing to mental disorders. METHODS: The elderly health examination database was obtained from the Department of Health, Taipei City government, from 2005 to 2012. A total of 86,061 people underwent publicly funded health examinations, with 348,067 visits. Each year, there are around 43,000 elderly persons in Taipei City using this service. We used a mental health questionnaire including five questions to estimated relative risks among potential risk factors with the generalized estimating equations (GEE) model to measure the mental health status of the elderly. Mood disorders were measured with the Brief Symptom Rating Scale (BSRS-5) questionnaire. Age, education level, gender, marital status, living alone, drinking milk, eating vegetables and fruits, long-term medication, smoking status, frequency of alcohol consumption, frequency of physical activity, BMI, and number of chronic diseases were included as covariates. RESULTS: The results show that being male (odds ratio (OR) 0.57; 95% CI = 0.56, 0.59), higher education (OR 0.88; 95% CI = 0.82, 0.95), no long-term medication (OR 0.57; 95% CI = 0.56, 0.58), and exercising three or more times per week (OR 0.94; 95% CI = 0.91, 0.98) were all positively correlated with better emotional status. However, being divorced (OR = 1.22, 95% CI = 1.09, 1.36), not drinking milk (OR = 1.12, 95% CI = 1.09, 1.14), not eating enough vegetables and fruits every day (OR = 1.78, 95% CI = 1.73, 1.83), daily smoking (OR = 1.15, 95% CI = 1.01, 1.32), and having more chronic diseases (OR = 1.02, 95% CI = 1.01, 1.03) were all correlated with poor mental status among the elderly. CONCLUSIONS: The findings of this research can both estimate the prevalence of mood disorders at the community level, and identify risk factors of mood disorders at the personal level.

A flow-based statistical model integrating spatial and nonspatial dimensions to measure healthcare access.

Assessing access to healthcare for an entire healthcare system involves accounting for demand, supply, and geographic variation. In order to capture the interaction between healthcare services and populations, various measures of healthcare access have been utilized, including the popular two-step floating catchment area (2SFCA) method. However, despite the many advantages of 2SFCA, the problems, such as inappropriate assumption of healthcare demand and failure to capture cascading effects across the system have not been satisfactorily addressed. In this paper, a statistical model for evaluating flows of individuals was added to the 2SFCA method (hereafter we refer to it as F2SFCA) in order to overcome limitations associated with its current restriction. The proposed F2SFCA model can incorporate both spatial and nonspatial dimensions and thus synthesizes them into one framework. Moreover, the proposed F2SFCA model can be easily adapted to measure access for different types of individuals, over different service provider types, or with capacity constraints in a healthcare system. We implemented the proposed model in a case study assessing access to healthcare for the elderly in Taipei City, Taiwan, and compared the weaknesses and strengths to the 2SFCA method and its variations.

Efficient programming of human mesenchymal stem cell-derived hepatocytes by epigenetic regulations.

BACKGROUND AND AIM: In view of its unique properties of detoxification and involvement of metabolic and biochemical functions, in vitro hepatocyte culture serves as a valuable material for drug screening and mechanistic analysis for pathology of liver diseases. The restriction of rapid de-differentiation and inaccessibility of human hepatocytes from routine clinical procedure, however, limits its use. METHODS: To address this issue, the effort to direct human mesenchymal stem cells (hMSCs) into hepatocytes using a modified protocol was proposed. With the additional treatment of histone deacetylase inhibitor (HDACi) and DNA methyltransferase inhibitor (DNMTi), in vitro hMSC-derived hepatocytes were cultivated and their hepatic characteristics were examined. RESULTS: By using a modified protocol, it was shown that Trichostatin A and 5-aza-2-deoxycitidine protected differentiating cells from death and could sufficiently trigger a wide range of liver-specific markers as well as liver functions including albumin production, glycogen storage, and urea cycle in hMSC-derived hepatocytes. The increased mRNA expression for hepatitis C virus (HCV) entry including CD81, Occludin, LDL receptor, and scavenger receptor class B type I in hMSC-derived hepatocytes was also detected, implying its potential to be utilized as an in vitro model to analyze dynamic HCV infection. CONCLUSIONS: The present study successfully established a protocol to direct hMSCs into hepatocyte-like cells suggesting the beneficial impact to apply HDACi and DNMTi as potent modulators for hMSCs to liver differentiation.

Differential microRNA Profiles Predict Diabetic Nephropathy Progression in Taiwan.

OBJECTIVES: Diabetic nephropathy (DN) is a major leading cause of kidney failure. Recent studies showed that serological microRNAs (miRs) could be utilized as biomarkers to identify disease pathogenesis; the DN-related miRs, however, remained to be explored. METHODS: A prospective case-control study was conducted. The clinical significance of five potential miRs (miR-21, miR-29a, miR-29b, miR-29c and miR192) in type 2 Diabetes Mellitus (T2DM) patients who have existing diabetic retinopathy with differential Albumin:Creatinine Ratio (ACR) and estimated Glomerular Filtration Rate (eGFR) was performed using quantitative RT-PCR analysis. The subjects with diabetic retinopathy enrolled in Taipei City Hospital, Taiwan, were classified into groups of normal albuminuria (ACR<30mg/g; N=12); microalbuminuria (30mg/g300mg/g; N=21) as well as 18 low-eGFR (eGFR<60ml/min) and 32 high-eGFR (eGFR>60ml/min). The level of serum miRs was statistically correlated with age, Glucose AC, ACR, eGFR and DN progression. RESULTS: The levels of miR-21, miR-29a and miR-192 were significantly enriched in the overt proteinuria group compared with microalbuminuria and/or overt proteinuria groups. It was shown that only miR-21 level was significantly up-regulated in low-eGFR group compared with high-eGFR patients. Interestingly, Pearson's correlation coefficient analysis demonstrated that DN progressors showed significantly greater levels of miR-21, miR-29a, miR-29b and miR-29c in comparison with non-progressors implying the clinical potential of DN associated miRs in monitoring and preventing disease advancement. CONCLUSION: Our findings showed that miR-21, miR-29a/b/c and miR-192 could reflect DN pathogenesis and serve as biomarkers during DN progression.

Measuring propionyl-CoA carboxylase activity in phytohemagglutinin stimulated lymphocytes using high performance liquid chromatography.

BACKGROUND: Propionyl-CoA carboxylase (PCC) is a mitochondrial enzyme involved in the catabolism of several essential amino acids and odd chain fatty acids. Previous PCC assays have involved either a radiometric assay or have required mitochondria isolation and/or enzyme purification. METHODS: We developed an enzymatic method to analyze PCC activity in phytohemagglutinin (PHA) stimulated lymphocytes that involves high performance liquid chromatography. RESULTS: The method shows good linearity and sensitivity. PCC activity was unaffected even when lymphocytes were isolated and PHA stimulated after a whole blood sample had been stored at 4°C for 5days. This indicates that this method is suitable for analyzing samples from distant medical centers. The PCC activity of patients with propionic acidemia was found to be much lower than that of normal individuals and carriers. However, this PCC assay is significantly affected by the red blood cell contamination. In conclusion, this is a reliable method for performing PCC assays and only requires 0.5 to 1.0ml of whole blood from newborns. CONCLUSIONS: The PCC assay established in this study is useful for the confirmation of PA in individuals, and prenatal diagnosis and genetic counseling for the affected families.

Association of thyroid-stimulating hormone and cardiovascular risk factors.

Thyroid hormone plays an important role in regulating the lipid and glucose metabolism. Previously, much attention has been drawn to define the pathophysiological relationship between thyroid dysfunction and the incidence of cardiovascular diseases (CVDs). While the conditions of overt hypothyroidism and subclinical hypothyroidism were both emphasized, the association between CVD risks and the deregulated circulating thyroid-stimulating hormone (TSH) level remains to be elucidated. Nevertheless, multiple TSH-mediated physiological adaptations, including alteration of the serum lipids, body mass index, blood pressure and insulin sensitivity, have led to the difficulty of clearly examining the association between the TSH level and CVD prevalence. The current review aims to 1) summarize the evidence for the role of thyroid dysfunction and TSH abnormality in CVD pathogenesis and 2) explore the possible underlying molecular mechanisms of TSH-mediated cardiovascular pathology in hopes of providing better therapeutic strategies for the patients with deregulated TSH.

Circulating microRNA as a diagnostic marker in populations with type 2 diabetes mellitus and diabetic complications.

Diabetes mellitus (DM) is a global health care issue resulting from hyperglycemia-mediated life-threatening complications. Although the use of glucose-lowering agents is routinely practiced, high dependence on medication leads to poor quality of life for DM patients. While it is still not feasible to precisely determine the critical timing when DM is truly established, perhaps the best way to reduce DM-associated mortality is to prevent it. To this end, an exploration of prognostic molecules sensitive enough to detect early physiological alteration at the initiating stage would be required. Recently discovered small noncoding molecules, microRNAs (miRs), in body fluid seem promising to be utilized as a biomarker to monitor DM initiation and progression, as it is believed that expression of circulating miRs reflects disease pathology. Current DM-related miRs were often referred to miRs differentially expressed in insulin target organs (liver, muscle, and adipose tissues) or circulating blood (peripheral blood) in diabetic patients compared to their control counterparts, although these miRs could merely be resultant nucleotides from DM-induced organ impairment instead of the indicators of onset/progression of DM. In the current review, studies showing circulating miRs associated with type 2 DM and its complications are summarized, and future scope of using miRs as biomarkers for disease prognosis/diagnosis is also emphasized.

Two frequent mutations associated with the classic form of propionic acidemia in Taiwan.

Propionyl-CoA carboxylase (PCC) is involved in the catabolism of branched chain amino acids, odd-numbered fatty acids, cholesterol, and other metabolites. PCC consists of two subunits, α and ß, encoded by the PCCA and PCCB genes, respectively. Mutations in the PCCA or PCCB subunit gene may lead to propionic acidemia. In this study, we performed mutation analysis on ten propionic acidemia patients from eight unrelated and nonconsanguineous families in Taiwan. Two PCCA mutations, c.229C→T (p.R77W) and c.1262A→C (p.Q421P), were identified in a PCCA-deficient patient. Six mutations in the PCCB gene, including c.-4156_183+3713del, c.580T→C (p.S194P), c.838dup (p.L280Pfs 11), c.1301C→T (p.A434V), c.1316A→G (P.Y439C), and c.1534C→T (p.R512C), were identified in seven PCCB-deficient families. The c.-4156_183+3713del mutation is the first known large deletion that affects the PCCB gene functions. Furthermore, the c.1301C→T and c.-4156_183+3713del mutations in the PCCB gene have not been reported previously. Clinical features demonstrated that these two frequent mutations are associated with low enzyme activity and a classic propionic acidemia phenotype.

A novel XK gene mutation in a Taiwanese family with McLeod syndrome.

McLeod syndrome is one subtype of rare neuroacanthocytosis syndromes characterized by misshapen red blood cells and progressive degeneration of the basal ganglia. It is an X-linked recessive disorder with mutation in the XK gene of the Kell blood group system with multisystem involvements. Concerning the movement disorders, its dyskinesias are various and difficult to differentiate from those in Huntington's disease or other hyperkinetic movement disorders. In this report, we described a 62-year-old male patient presenting with insidious myalgia and muscle fatigue. Progressive motor restlessness and toes choreoathetosis were noted. Previously, he had chronic psychotic disorder with irregular treatment for 14 years. The laboratory tests revealed elevated creatine phosphokinase and acanthocytes (36.3%). The electrophysiological test demonstrated an axonal type polyneuropathy. The neuroimaging of brain showed striatal degeneration. Genetic analysis revealed a nonsense hemizygous mutation c.154C>T (p.Gln52X) at exon 1 of XK gene. The genetic counseling of his family revealed one elder brother carrying the same mutation and showing a similar but very mild syndrome. Several offspring were the asymptomatic carriers. We suggest that for a patient with multiple system disorders including dyskinetic movement disorders, psychiatric symptoms, polyneuropathy, and elevated CPK, a genetic test for XK gene mutation is highly indicated to confirm the McLeod syndrome and to guide the possible therapy.

Mutation spectrum of and founder effects affecting the PTS gene in East Asian populations.

The enzyme 6-pyruvoyl-tetrahydropterin synthase (PTPS, gene symbol: PTS) is involved in the second step of the de novo biosynthesis of tetrahydrobiopterin (BH4), which is a vital cofactor of nitric oxide synthases and three types of aromatic amino acid hydroxylases; the latter are important enzymes in the production of neurotransmitters. We conducted a study of PTS mutations in East Asia, including Taiwan, Mainland China, Japan, South Korea, the Philippines, Thailand and Malaysia. A total of 43 mutations were identified, comprising 22 previously reported mutations and 21 new discovered mutations. Among these, the c.155A>G, c.259C>T, c. 272A>G, c.286G>A and c.84-291A>G mutations were the most common PTS mutations in East Asia, while the c.58T>C and c.243G>A mutations were, respectively, specific to Filipinos and Japanese originating from Okinawa. Further studies demonstrated that each of the mutations listed above was in linkage disequilibrium to a specific allele of polymorphic microsatellite marker, D11S1347. These results suggest the presence of founder effects that have affected these frequent mutations in East Asia populations. In this context, D11S1347 should become one of the most reliable polymorphic markers for use in prenatal diagnosis among PTPS deficient families, especially where mutations are yet to be identified.

Dysferlin associates with the developing T-tubule system in rodent and human skeletal muscle.

Mutations in the dysferlin gene cause limb-girdle muscular dystrophy type 2B, Miyoshi myopathy, and distal anterior compartment myopathy. Dysferlin mainly localizes to the sarcolemma in mature skeletal muscle where it is implicated in membrane fusion and repair. In different forms of muscular dystrophy, a predominantly cytoplasmic localization of dysferlin can be observed in regenerating myofibers, but the subcellular compartment responsible for this labeling pattern is not yet known. We have previously demonstrated an association of dysferlin with the developing T-tubule system in vitro. To investigate the role of dysferlin in adult skeletal muscle regeneration, we studied dysferlin localization at high resolution in a rat model of regeneration and found that the subcellular labeling of dysferlin colocalizes with the developing T-tubule system. Furthermore, ultrastructural analysis of dysferlin-deficient muscle revealed primary T-tubule anomalies similar to those seen in caveolin-3-deficient muscle. These findings indicate that dysferlin is necessary for correct T-tubule formation, and dysferlin-deficient skeletal muscle is characterized by abnormally configured T-tubules.

Attenuated muscle regeneration is a key factor in dysferlin-deficient muscular dystrophy.

Skeletal muscle requires an efficient and active membrane repair system to overcome the rigours of frequent contraction. Dysferlin is a component of that system and absence of dysferlin causes muscular dystrophy (dysferlinopathy) characterized by adult onset muscle weakness, high serum creatine kinase levels and a prominent inflammatory infiltrate. We have observed that dysferlinopathy patient biopsies show an excess of immature fibres and therefore investigated the role of dysferlin in muscle regeneration. Using notexin-induced muscle damage, we have shown that regeneration is attenuated in a mouse model of dysferlinopathy, with delayed removal of necrotic fibres, an extended inflammatory phase and delayed functional recovery. Satellite cell activation and myoblast fusion appear normal, but there is a reduction in early neutrophil recruitment in regenerating and also needle wounded muscle in dysferlin-deficient mice. Primary mouse dysferlinopathy myoblast cultures show reduced cytokine release upon stimulation, indicating that the secretion of chemotactic molecules is impaired. We suggest an extension to the muscle membrane repair model, where in addition to fusing patch repair vesicles with the sarcolemma dysferlin is also involved in the release of chemotactic agents. Reduced neutrophil recruitment results in incomplete cycles of regeneration in dysferlinopathy which combines with the membrane repair deficit to ultimately trigger dystrophic pathology. This study reveals a novel pathomechanism affecting muscle regeneration and maintenance in dysferlinopathy and highlights enhancement of the neutrophil response as a potential therapeutic avenue in these disorders.