Neurodegeneration with Brain Iron Accumulation

Lee, Jae-Hyeok Interdisciplinary Society of GeneticGenomic Medici 2020 Journal of interdisciplinary genomics Vol.2 No.1

Recent advances in magnetic resonance imaging and identification of causative genes led to the recognition of a new group of disorders named neurodegeneration with brain iron accumulation (NBIA). NBIA is a group of inherited disorders characterized by abnormal iron deposition in the brain, usually in the basal ganglia. The disorder shares the clinical features of movement disorders and is accompanied by varying degrees of neuropsychiatric abnormalities. In this review, the causative genes, clinical presentations, neuroimaging features, and pathological findings are summarized.

β-ureidopropionase Deficiency

Jun Hwa Lee Interdisciplinary Society of GeneticGenomic Medici 2023 Journal of interdisciplinary genomics Vol.5 No.1

β-ureidopropionase (β-UP) is an enzyme that catalyzes the final step in the pyrimidine degradation pathway, which converts β-ureidopropionate and β-ureidoisobutyrate into β-alanine and β-aminoisobutyrate, respectively. β-UP deficiency (UPB1D; OMIM # 613161) is an extremely rare autosomal recessive inborn error disease caused by a mutation in the UPB1 gene on chromosome 22q11. To date, approximately 40 cases of UPB1D have been reported worldwide, including one case in Korea. The clinical manifestations of patients with UPB1D are known to be diverse, with a very wide range of manifestations being previously reported; these manifestations include completely asymptomatic, urogenital and colorectal anomalies, or severe neurological involvement, including global developmental delay, microcephaly, early onset psychomotor retardation with dysmorphic features, epilepsy, optic atrophy, retinitis pigmentosa, severely delayed myelination, and cerebellar hypoplasia. Currently, diagnosis of UPB1D is challenging as neurological manifestations, MRI abnormalities, and biochemical analysis for pyrimidine metabolites in the urine, plasma, and cerebrospinal fluid also need to be confirmed by UPB1 gene mutations. Overall, treatment of patients with UPB1D is palliative as there is still no definitive curative treatment available.

Pseudogenes: Nuances and Nuisances in Molecular Diagnostics

Oh, Seung Hwan Interdisciplinary Society of GeneticGenomic Medici 2022 Journal of interdisciplinary genomics Vol.4 No.2

Pseudogenes are genomic regions that contain gene-like sequences that have a high similarity to the known genes but are nonfunctional. They are categorized into processed, unprocessed, and unitary pseudogenes. Unprocessed pseudogenes generated by duplications can be problematic in sequencing approaches in molecular diagnostics. We discuss the risk of misdiagnosis when investigating genes with pseudogenes of high homology, and describe a method for identifying these small and annoying differences between parent genes and pseudogenes, including parent gene-specific assay design.

Growth Outcome and Metabolic Profile of PWS Patients Treated with GH and Differences between AGA and SGA Group

Yoon, Ju Young Interdisciplinary Society of GeneticGenomic Medici 2022 Journal of interdisciplinary genomics Vol.4 No.2

Background: Prader-Willi syndrome (PWS) is a complex genetic disease associated with growth impairment, severe obesity and metabolic dysfunctions. High proportion of PWS patients are born small for gestational age (SGA) than normal children, which also increase the risk of growth impairment and metabolic dysfunction in PWS. We aimed to compare growth outcome and metabolic profiles between SGA and appropriate for gestational age (AGA) PWS patients. Methods: Data of 55 PWS children and adults aged more than 2 years old (32 male and 23 female, age 2-18.8 years) from single center were studied. Only patients who were treated with GH were included. The clinical characteristics and laboratory findings were reviewed retrospectively. Results: Among 55 subjects, 39 had 15q11-13 deletion and 16 had uniparental disomy (UPD). Twenty (36.3%) were born SGA. All patients received GH treatment, and 11 (20%) discontinued GH treatment. Mean age at GH treatment initiation was 2.5 (range 0.3-12.4) years, and mean duration of treatment was 6.3 (range 1.0-11.3) years. Current height-SDS (-0.36 vs -0.16) and BMI-SDS (1.44 vs 1.33) did not differ between AGA and SGA group. Two patients in SGA group, but none in AGA group had diabetes mellitus. Mean glucose level was also higher in SGA group (100.1 vs 114.4 mg/dL). Conclusion: Our report gives an overview of growth profile and metabolic dysfunctions recorded in GH treated PWS patients. Growth profile did not differ between AGA and SGA group. Glucose level was higher in SGA group, so more careful monitoring and prevention for DM will be required in SGA group.

Klinefelter Syndrome: Review of the Literature

Jun, Kyung Ran Interdisciplinary Society of GeneticGenomic Medici 2022 Journal of interdisciplinary genomics Vol.4 No.2

Klinefelter's syndrome (KS) is a syndrome with extra X chromosome(s), in XY individuals, characterized by gynecomastia, small testes, and infertility. Additional X chromosomes can be present as variable karyotypic forms, including mosaicism (47,XXY/46,XY). The reported prevalence of KS ranges from one in 500 to one in 1,000 live males, but is probably underestimated. The classic phenotype is small, firm testes and infertility resulting from seminiferous tubule dysgenesis and androgen deficiency. The spectrum of KS includes tall stature with relatively long legs and arm span, decreased body hair, learning disabilities, behavioral problems, poor motor skills, and other important medical issues, such as metabolic syndrome, diabetes, autoimmune diseases, cardiovascular disease, certain neoplasia. The increased risk of certain medical problems in KS can be attributed to a direct effect of the extra X chromosome, the combined action of multiple genomic and epigenetic factors, or the hormonal imbalances. Typically, chromosome analysis is not ordered for adult patients with general medical conditions, except for suspected cases of hematologic and lymphoid disorders. Even though it was found during work-up for certain disorders in adult patient, most physicians do not suspect KS or consider its impact. Therefore, understanding the pathophysiology and variable manifestation in KS is necessary, and discussions with multidisciplinary teams will help to diagnose and treat males with KS.

A Heterogeneous Genetic Disorder: Primary Ciliary Dyskinesia

Ahn, Ji Young Interdisciplinary Society of GeneticGenomic Medici 2022 Journal of interdisciplinary genomics Vol.4 No.1

Primary ciliary dyskinesia (PCD) is a genetic disorder that affects approximately 1 in 15,000-30,000 people, with the majority of patients inheriting the disorder via autosomal recessive inheritance. PCD is characterized by abnormal ciliary ultrastructure and/or function, which results in impaired mucociliary clearance and recurrent respiratory infections. Despite the presence of symptoms from birth, many patients with PCD remain undiagnosed until adulthood. Many advances in the diagnosis of PCD have occurred in recent years, including nasal nitric oxide assays, ciliary motility tests, and genetic sequencing. Early diagnosis and symptom management may reduce morbidity and mortality from PCD improving the patient's quality of life.

Targeted Panel Exome Sequencing in Suspected Monogenic Diabetes: Single-Center Pilot Study

Lee, Sangwoo,Lee, Gi Min,Lee, MiSeon,Lee, Rosie,Moon, Jung Eun Interdisciplinary Society of GeneticGenomic Medici 2022 Journal of interdisciplinary genomics Vol.4 No.1

Purpose:Maturity onset diabetes of the young (MODY) is the most common hereditary form of diabetes mellitus (DM), with similar clinical manifestations to type 1 or type 2 DM, leading to diagnostic ambiguity. Despite increased genetic research on monogenic DM, studies with Asian populations are limited. Therefore, we investigated mutation in possible monogenic DM and MODY in Korean children and aldolescents. Methods: Targeted panel exome sequencing including 32 targets genes was performed for 41 patients with suspected monogenic DM at Kyungpook National University Children's Hospital. Results: Variants were detected in 19 patients, including those in known MODY-associated genes (HNF4A, GCK, HNF1A, CEL, PAX4, INS, and BLK) and monogenic DM-associated genes (WFS1, FRX6, and GLIS3). Conclusion: MODY variants were detected more than expected. Targeted exon sequencing is helpful in diagnosing MODY or possible monogenic DM patients.

Prophylactic Mastectomy and Implant-Based Breast Reconstruction of BRCA1/2 Mutation-Positive Patients in Korea

Lee, Joon Seok,Lee, Jeeyeon,Park, Ho Yong,Yang, Jung Dug Interdisciplinary Society of GeneticGenomic Medici 2022 Journal of interdisciplinary genomics Vol.4 No.1

Purpose: Mastectomy is performed as a surgical treatment for patients with breast cancer who have the BRCA 1/2 mutation. In this study, we have reported the trends in Korea for both immediate breast reconstruction and prophylactic mastectomy. Methods: This retrospective study was conducted from 2019 to 2021. Both skin-sparing mastectomy and immediate implant-based breast reconstruction with prepectoral and/or subpectoral techniques were performed in five patients with BRCA 1/2 mutations. Data on age; body mass index; cancer stage; BRCA 1/2 mutation; estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 expression; diagnosis; and complications were collected. Results: The average (±standard deviation [SD]) age was 44.0±6.48 years old; BMI 24.5±2.25 kg/m²; and breast volumes were 365.8±70.34 and 382.4±96.33 cc for right and left ones, respectively. The BRCA 1 and 2 were diagnosed in four and one patients, respectively. The estrogen and progesterone receptors and human epidermal growth factor receptor 2 were detected in one (20%), one (20%), and three (60%) patients, respectively. The applied implant-based breast reconstruction techniques for ten breasts were subpectoral technique (n=7, 70%) and prepectoral technique (n=3, 30%). For the cancer stage, those with I, II, and III stages were one (20%), two (40%), and one (20%), respectively. There were no major complications such as Infection, seroma. Conclusion: When mastectomy is performed as surgical treatment in BRCA 1/2 mutation positive breast cancer patients, it is possible to obtain a better outcome with both implant-based breast reconstruction and different circumstances between breast cancer and contralateral breast.

Microarray Analysis of Extracranial Arteriovenous Malformation Endothelial Cells

Lee, Joon Seok,Oh, Eun Jung,Kim, Hyun Mi,Kwak, Suin,Lee, Seok-Jong,Lee, Jongmin,Huh, Seung,Kim, Ji Yoon,Chung, Ho Yun Interdisciplinary Society of GeneticGenomic Medici 2022 Journal of interdisciplinary genomics Vol.4 No.2

Background: Arteriovenous malformations (AVMs) are rare diseases comprising abnormally dilated arteries and veins with an absence of a capillary network. Since these diseases are intractable after diagnosis, various treatment strategies have been examined, with continuous efforts to identify target genes. Here, we report relevant new target genes selected via gene microarray. Methods: Endothelial cells were isolated from samples collected from three patients with AVM and three healthy individuals, followed by microarray analysis. Additionally, quantitative PCR was performed to select genes highly relevant to AVM. Results: In the vascular endothelial cells derived from the tissues of patients with AVM, the expression of ANGPT1, ANGPT2, DLL4, IL6, NRG1, TGFBR1, and VEGFA was typically higher compared to those derived from normal tissues. Conclusion: Seven candidate genes were selected to analyze the pathophysiological mechanism of AVM. These results may aid in future directions of diagnosis and treatment.

Resistance to Thyroid Hormone Syndrome Mutation in THRB and THRA: A Review

Jung Eun Moon Interdisciplinary Society of GeneticGenomic Medici 2023 Journal of interdisciplinary genomics Vol.5 No.2

Resistance to thyroid hormone syndrome (RTH) is a genetic disease caused by the mutation of either the thyroid hormone receptor-β (THRB) gene or the thyroid hormone receptor-α (THRA) gene. RTH caused by THRB mutations (RTH-β) is characterized by the target tissue's response to thyroid hormone, high levels of triiodothyronine and/or thyroxine, and inappropriate secretion of thyroid-stimulating hormone (TSH). THRA mutation is characterized by hypothyroidism that affects gastrointestinal, neurological, skeletal, and myocardial functions. Most patients do not require treatment, and some patients may benefit from medication therapy. These syndromes are characterized by decreased tissue sensitivity to thyroid hormones, generating various clinical manifestations. Thus, clinical changes of resistance to thyroid hormones must be recognized and differentiated, and an approach to the practice of personalized medicine through an interdisciplinary approach is needed.