Systematic Approach for Drug Repositioning of Anti-Epileptic Drugs

Epilepsy is a central neurological disorder affecting individuals of all ages and causing unpredictable seizures. In spite of the improved efficacy of new antiepileptic drugs and novel therapy, there are still approximately 20%~30% of patients, who have either intractable or uncontrolled seizures. The epilepsy drug-target network (EDT) is constructed and successfully demonstrates the characteristics and efficacy of popularly used AEDs through the identification of causative genes for 60 epilepsy patients. We discovered that the causative genes of most intractable patients were not the targets of existing AEDs, as well as being very far from the etiological mechanisms of existing AEDs in the functional networks. We show that the existence of new drugs that target the causative genes of intractable epilepsy patients, which will be potential candidates for refractory epilepsy patients. Our systematic approach demonstrates a new possibility for drug repositioning through the combination of the drug-target and functional networks.ope

The First Case Series of Cryopyrin-Associated Periodic Syndrome in Korea

Cryopyrin-associated periodic syndrome (CAPS) is a hereditary autoinflammatory syndrome caused by mutations in NLRP3 (encoding cryopyrin), which presents with fever, fatigue and arthralgia. Thus far, however there have been no reports of CAPS in Korea. Herein, we report 3 cases of CAPS for the first time in Korea. The first case, a 28-year-old man with recurrent urticaria, arthralgia and fever induced by cold, all of which were observed in his father, showed elevated erythrocyte sedimentation rate and C-reactive protein. He exhibited a p.Gly303Asp variant of the NLPR3 gene. The second case, a 2-year-old girl who had recurrent urticaria, arthritis and oral and genital ulcers, was positive for HLA B51 and a p.Glu569Lys mutation in exon 3 of the NLRP3 gene. Administration of anakinra greatly improved her symptoms. The third case, a 4-year-old boy who presented with recurrent urticaria, arthralgia, and fever, exhibited a p.Val72Met mutation in exon 1 of the NLRP3 gene. Administration of tocilizumab improved all of his symptoms. This small case series suggests that clinicians consider CAPS and conduct genetic studies when arthralgia and fever are accompanied by urticaria in Korea.ope

A novel compound heterozygous mutation of the AIRE gene in a patient with autoimmune polyendocrine syndrome type 1

Autoimmune polyendocrine syndrome type 1 (APS-1), or autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy is a rare, autosomal recessive autoimmune disease caused by a mutation of the autoimmune regulator (AIRE) gene. The main symptom triad in APS-1 comprises chronic mucocutaneous candidiasis, adrenal insufficiency, and hypoparathyroidism. Various autoimmune diseases and ectodermal abnormalities are also commonly associated with the syndrome. The treatment of APS-1 includes hormone replacement and symptom control. It is important to monitor such patients for clinical manifestations of their disease through regular follow-up. We report the case of a 10-year-old Korean girl with APS-1 due to a novel compound heterozygous mutation of the AIRE gene. This patient's main clinical manifestations were adrenal insufficiency and chronic mucocutaneous candidiasis. The patient had a previously known pathogenic variant of c.1513delG (p.Ala505ProfsTer16), and a newly discovered variant of c.1360dupC (p.His454ProfsTer50).ope

Recombinant adeno-associated virus mediated gene transfer in a mouse model for homocystinuria

Homocystinuria is a metabolic disorder caused by a deficiency of cystathionine beta-synthase (CBS). The major clinical symptoms of this disease are mental retardation, lens dislocation, vascular disease with life-threatening thromboembolisms, and skeletal deformities. The major treatments for CBS deficiency include pharmacologic doses of pyridoxine or dietary restriction of methionine. There is currently no effective long-term treatment to lower the elevated plasma levels of homocysteine. However, gene therapy could be an effective novel approach for the treatment of homocystinuria. A recombinant adeno- associated virus vector carrying human CBS cDNA (rAAV-hCBS) was constructed and administered to CBS-/- mice by intramuscular (IM) and intraperitoneal (IP) injections. Serum homocysteine concentrations significantly decreased in treated mice compared with age-matched controls two weeks after treatment. The treated CBS-/- mice had life spans 3-7 days longer compared with untreated CBS-/- mice. In CBS-/- mice treated with rAAV-hCBS via IP injection, the vector was detected in all organs examined including liver, spleen, and kidney, and CBS gene expression was observed by immunohistochemical staining in the liver. These results indicate the efficacy of gene delivery and demonstrate the possibility of gene therapy mediated by AAV gene transfer in this mouse model of homocystinuria.ope

Generation of induced pluripotent stem cells (KSCBi009-A) from a patient with Prader-Willi syndrome (PWS) featuring deletion of the paternal chromosome region 15q11.2-q13

Prader-Willi syndrome (PWS) is a neurodevelopmental disorder caused by the loss of paternally expressed genes in an imprinted region of chromosome 15q11.2-q13. We generated a human-induced pluripotent stem cell line, designated KSCBi009-A, from peripheral blood mononuclear cells of a 13-year-old male PWS patient exhibiting deletion of the paternal chromosome 15q11.2-q13 region. The deletion was confirmed via methylation-specific multiplex ligation probe amplification assay (MS-MLPA) of genomic DNA. The hiPSC line expressed pluripotency markers and differentiated into three germ layers. The cell line may serve as a valuable model of an imprinting PWS disorder useful in terms of drug discovery and development.ope

Generation of patient-specific induced pluripotent stem cells (KSCBi007-A) derived from a patient with Prader-Willi syndrome retain maternal uniparental disomy (UPD)

Prader-Willi syndrome (PWS) is a neurodevelopmental disorder caused by loss of paternally expressed genes in an imprinted region of 15q11.2-q13. We established a human-induced pluripotent stem cell (hiPSC) line, KSCBi007-A, from the peripheral blood mononuclear cells of a 5-month-old girl with PWS that retained maternal uniparental disomy (UPD). Methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) of genomic DNA revealed the maternal UPD in the hiPSCs. The generated hiPSC line expressed pluripotency markers and showed the ability to differentiate into three germ layers in vitro. This hiPSC line could be used as a cellular model of an imprinting disorder in humans.ope

Chronic Hereditary Tyrosinemia Type I with Novel Mutation in FAH Gene

A 22-month-old girl who had taken iron supplements due to iron deficiency anemia, presented bloody mucoid stool for one month. She had a bruise at the right periorbital area due to minor trauma and hepatosplenomegaly. Laboratory studies showed anemia, thrombocytopenia, elevated alkaline phosphatase (ALP), hypophosphatemia, decreased haptoglobin, hypocomplementemia, negative direct/indirect Coomb's test, normal vitamin D3 level and high PTHi. Wrist x-ray showed no signs of rickets. The abdominal ultrasound showed only accessory spleen. Tandem mass spectrometry was normal. During follow up, bloody stool regressed after seven days of withdrawal of iron supplement and cow milk, and the total CO2 level had been within 15-20 mEq/L with normal anion gap. NGS (next generation sequencing) panel test for evaluation of renal tubular acidosis showed negative results. After low dose steroid and vitamin D supplements under the impression of hypocomplementemic vasculitis, thrombocytopenia, C3/C4, decreased haptoglobin, and elevated ALP level became normal. At 57 months of age, laboratory findings showed elevated liver enzyme, ALP and gamma-glutamyl transferase again. And liver cirrhosis with splenomegaly and diffuse renal disease were reported with abdomen CT scan. Liver biopsy reported macro- and micronodular cirrhosis. Urine organic acid profile showed elevated succinylacetone level. Whole exome sequencing revealed novel compound heterozygous mutations (NM_00137.2:c.107T>C, NM_00137, 2:c.614T>C) in FAH gene and confirmed by Sanger sequencing. Consequently, the patient was diagnosed as chronic hereditary tyrosinemia type I. She started low phenylalanine/tyrosine diet and nitisinone treatment. Our case had presented symptoms very slowly, which is the first case of chronic tyrosinemia type I in South Korea.ope

Prevalent and Novel Mutations of the Tyrosinase Gene in Korean Patients with Tyrosinase-deficient Oculocutaneous Albinism

We analyzed the tyrosinase (TYR) gene of 12 Korean patients with various types of oculocutaneous albinism (OCA). We identified five different mutations in the TYR gene in 4 patients with severe OCA and in 2 patients with mild OCA, but found no mutations in the 6 patients with mild OCA phenotypes. Among the 5 mutations, a frameshift mutation, P310insC, was detected most frequently (allele frequency = 0.5), and the other mutations were found less frequently, two of which, L288delT and IVS2-7t-->a,-10(-)-11deltt, are novel. This study may provide valuable information for the molecular diagnosis of and accurate genetic counseling for OCA1 in Koreans and perhaps other Asian groups.ope

Prevalence of Rare Genetic Variations and Their Implications in NGS-data Interpretation

Next-generation sequencing (NGS) technology has improved enough to discover mutations associated with genetic diseases. Our study evaluated the feasibility of targeted NGS as a primary screening tool to detect causal variants and subsequently predict genetic diseases. We performed parallel computations on 3.7-megabase-targeted regions to detect disease-causing mutations in 103 participants consisting of 81 patients and 22 controls. Data analysis of the participants took about 6 hours using local databases and 200 nodes of a supercomputer. All variants in the selected genes led on average to 3.6 putative diseases for each patient while variants restricted to disease-causing genes identified the correct disease. Notably, only 12% of predicted causal variants were recorded as causal mutations in public databases: 88% had no or insufficient records. In this study, most genetic diseases were caused by rare mutations and public records were inadequate. Most rare variants, however, were not associated with genetic diseases. These data implied that novel, rare variants should not be ignored but interpreted in conjunction with additional clinical data. This step is needed so appropriate advice can be given to primary doctors and parents, thus fulfilling the purpose of this method as a primary screen for rare genetic diseases.ope

Identification of disease comorbidity through hidden molecular mechanisms

Despite multiple diseases co-occur, their underlying common molecular mechanisms remain elusive. Identification of comorbid diseases by considering the interactions between molecular components is a key to understand the underlying disease mechanisms. Here, we developed a novel approach utilizing both common disease-causing genes and underlying molecular pathways to identify comorbid diseases. Our approach enables the analysis of common pathologies shared by comorbid diseases through molecular interaction networks. We found that the integration of direct genetic sharing and indirect high-level molecular associations revealed significantly strong consistency with known comorbid diseases. In addition, neoplasm-related diseases showed high comorbidity patterns within themselves as well as with other diseases, indicating severe complications. This study demonstrated that molecular pathway information could be used to discover disease comorbidity and hidden biological mechanism to understand pathogenesis and provide new insight on disease pathology.ope