Frequently Delayed Diagnosis and Misdiagnosis in MYH9-related Disorders: Data from Genetically Confirmed Cases of Korean Patients

MYH9-related disorders (MYH9RD) are autosomal-dominant disorders characterized by macrothrombocytopenia with or without leukocyte inclusion bodies or extra-hematological features, such as sensorineural deafness and renal impairment. MYH9RD can be misdiagnosed as an acquired form of thrombocytopenia including immune thrombocytopenic purpura (ITP). This leads to delayed diagnosis or administration of ineffective treatment. In the present study, we investigated the clinical and molecular characteristics of five unrelated Korean patients with MYH9RD and their family members, from four institutions. We reviewed clinical and laboratory data including extra-hematological manifestations. MYH9 pathogenic variants were detected by direct sequencing in all probands and the affected family members (N=10): two probands with c.5521G>A (p.Glu1841Lys) and one proband each with c.99G>T (p.Trp33Cys), c.287C>T (p.Ser96Leu), and c.3493C>T (p.Arg1165Cys). All patients had macrothrombocytopenia. Only the proband with Ser96Leu had extra-hematological manifestations. Past history revealed that two patients had been misdiagnosed with ITP and one of them had received a splenectomy. We validated the frequency of misdiagnosis (~20%) and genotype-phenotype correlations through a comprehensive review of previously reported cases of MYH9RD in Korea. It is important to suspect MYH9RD in patients with thrombocytopenia, and timely identification of macrothrombocytopenia and MYH9 pathogenic variants is required for early and accurate diagnosis of MYH9RD.

Efficacy of Annexin A1 Immunostaining in Bone Marrow for the Diagnosis of Hairy Cell Leukemia

Splenic B-cell lymphomas (SBCLs) show characteristically pronounced splenomegaly without significant lymphadenopathy. Distinguishing hairy cell leukemia (HCL) from other SBCLs (splenic marginal zone lymphoma [SMZL], variant HCL [v-HCL], and splenic diffuse red pulp small B-cell lymphoma [SDRPL]) is essential to determine suitable treatments and prognoses. With advances in diagnostic modalities and therapies, splenectomy is not commonly performed, and thus diagnosis of HCL must be based on the results obtained using blood and bone marrow samples. Annexin A1 is known as the most specific marker for HCL. There has yet been no report of the assessment of annexin A1 immunostaining from Korea. In this study we analyzed samples from 13 Korean patients with SBCLs (three HCL, three v-HCL, six SMZL, and one SDRPL) from May 2001 to December 2016. Immunohistochemical analyses for annexin A1 and CD20 were performed using bone marrow sections; molecular analyses for detection of the BRAF V600E mutation were also performed. All HCL patients showed positive results for annexin A1 immunostaining and the presence of the BRAF V600E mutation, and negative results for other SBCLs. Our results confirmed the high specificity of annexin A1 and the BRAF V600E mutation as HCL markers. Molecular analysis requires expensive equipment and substantial manpower. Annexin A1 is a better alternative as an HCL marker than the BRAF V600E mutation in terms of cost-effectiveness.

Importance of Specimen Type and Quality in Diagnosing Middle East Respiratory Syndrome

No abstract available.

Marked Increase of Circulating Double-Negative gammadelta T Cells in a Patient With Hydroa Vacciniforme-Like Lymphoma

No abstract available.

Genetic Confirmation of Congenital Factor V Deficiency in Korean Patients

No abstract available.

Detection of MYD88 L265P in patients with lymphoplasmacytic lymphoma/Waldenstrom macroglobulinemia and other B-cell non-Hodgkin lymphomas

BACKGROUND: Recent studies have identified a high prevalence of the MYD88 L265P mutation in lymphoplasmacytic lymphoma (LPL)/Waldenstrom macroglobulinemia (WM) cases, whereas low frequencies have been observed in other B cell non-Hodgkin lymphomas (NHLs). METHODS: We evaluated the sensitivity of the mutant enrichment 3'-modified oligonucleotide (MEMO)-PCR technique, a new detection method. We examined the MYD88 L265P mutation in a series of Korean patients with LPL/WM and other B cell NHLs in bone marrow aspirates, using the MEMO-PCR technique. RESULTS: The sensitivity of MEMO-PCR was estimated to be approximately 10-16.7%. MYD88 L265P was detected in 21 of 28 LPL cases (75%) and only three of 69 B cell NHL cases (4.3%). CONCLUSION: Although MEMO-PCR had relatively low sensitivity, we confirmed the high prevalence of the MYD88 L265P mutation in Korean LPL patients. Our study suggests the diagnostic value of MYD88 L265P for differentiating B-cell NHLs.

Annual Report on the External Quality Assessment of Diagnostic Genetics in Korea (2015)

The Diagnostic Genetics Subcommittee of Korean Association of External Quality Assessment Service conducted two trials in 2015 based on cytogenetics and molecular genetics surveys. A total of 43 laboratories participated in the chromosome surveys, 31 laboratories participated in the fluorescence in situ hybridization surveys, and 133 laboratories participated in the molecular genetics surveys. All except one laboratory showed acceptable results in the cytogenetics surveys. The molecular genetics surveys included the following tests: Mycobacterium tuberculosis detection, hepatitis B and C virus detection and quantification, human papilloma virus genotyping, gene rearrangement tests for leukaemias and lymphomas, genetic tests for JAK2, FMS-like tyrosine kinase 3, nucleophosmin, cancer-associated genes (KRAS, EGFR, KIT, and BRAF), hereditary breast and ovarian cancer genes (BRCA1 and BRCA2), Li-Fraumeni syndrome (TP53), Wilson disease (ATP7B), achondroplasia (FGFR3), hearing loss and deafness (GJB2 ), multiple endocrine neoplasia 2 (RET), Huntington disease, spinocerebellar ataxia, spinal and bulbar muscular atrophy, mitochondrial encephalopathy with lactic acidosis and stroke like episodes, myoclonic epilepsy ragged red fibre, Leber hereditary optic neuropathy, Prader-Willi/Angelman syndrome, Duchenne muscular dystrophy, spinal muscular atrophy, fragile X syndrome (FMR1), apolipoprotein E genotyping, methylenetetrahydrofolate reductase genotyping, ABO genotyping, cytochrome P450 2C9 genotyping, cytochrome P450 2C19 genotyping, and DNA sequencing analysis. The molecular genetics surveys showed excellent results for most of the participants. The external quality assessment program for genetics analysis in 2015 proved to be helpful for continuous education and the evaluation of quality improvement.

Annual Report on the External Quality Assessment Scheme for Diagnostic Genetics in Korea (2014)

Quality control for genetic tests has become more important as testing volume and clinical demands have increased dramatically. The diagnostic genetics subcommittee of Korean Association of External Quality Assessment Service conducted two trials in 2014 based on cytogenetics and molecular genetics surveys. A total of 44 laboratories participated in the chromosome surveys, 33 laboratories participated in the fl uorescence in situ hybridization (FISH) surveys, and 130 laboratories participated in the molecular genetics surveys as a part of these trials. All laboratories showed acceptable results in the chromosome and FISH surveys. The molecular genetics surveys included various tests: Mycobacterium tuberculosis detection, hepatitis B and C virus detection and quantification, human papilloma virus genotyping, gene rearrangement tests for leukaemia and lymphomas, genetic tests for JAK2, FMS-like tyrosine kinase 3, nucleophosmin, cancer-associated genes (KRAS, EGFR, KIT, and BRAF), hereditary breast and ovarian cancer genes (BRCA1 and BRCA2), Li-Fraumeni syndrome (TP53), Wilson disease (ATP7B), achondroplasia (FGFR3), Huntington disease, spinocerebellar ataxia, spinal and bulbar muscular atrophy, mitochondrial encephalopathy with lactic acidosis and stroke like episodes, myoclonic epilepsy ragged red fibre, Prader-Willi/Angelman syndrome, Duchenne muscular dystrophy, spinal muscular atrophy, fragile X syndrome, nonsyndromic hearing loss and deafness (GJB2), multiple endocrine neoplasia 2 (RET), Leber hereditary optic neuropathy (major mutation), apolipoprotein E genotyping, methylenetetrahydrofolate reductase genotyping, ABO genotyping, and DNA sequencing analysis. Molecular genetic surveys showed excellent results for most of the participants. The external quality assessment program for genetic analysis in 2014 proved to be helpful for continuous education and the evaluation of quality improvement.

Identification of Mixed Lineage Leukemia Gene (MLL)/MLLT10 Fusion Transcripts by Reverse Transcription-PCR and Sequencing in a Case of AML With a FISH-Negative Cryptic MLL Rearrangement

No abstract available.

A Case of Heterozygous alpha(+)-Thalassemia Diagnosed in a Korean Family by Using Multiplex Ligation-Dependent Probe Amplification / 임상검사와정도관리

Alpha-thalassemia (alpha-thalassemia), which is prevalent in the Mediterranean region, is caused by deficient synthesis of the alpha-globin chains. It is commonly caused by HBA1 and/or HBA2 gene deletion and is diagnosed by DNA sequence analysis. The proband was a 38-year-old woman who was found to have microcytic and hypochromic anemia on a routine health checkup. Results of the Hb electrophoresis (EP) and direct sequencing of the HBA1 and HBA2 genes were found to be normal. As multiplex ligation-dependent probe amplification (MLPA) for the HBA1 and HBA2 genes revealed heterozygous deletion, she was diagnosed with heterozygous alpha+-thalassemia. Although routine laboratory tests revealed similar findings in the proband's father, brother and niece, MLPA revealed heterozygous deletions of the HBA1 or HBA2 gene in her brother and niece. In summary, we report a case of heterozygous alpha+-thalassemia in a Korean family that was detected by MLPA. We recommend that patients with suspected hemoglobinopathies should be followed-up further with MLPA, especially when Hb EP shows a normal pattern.

Evaluation of a Modified Enzyme Linked Immunosorbent Assay for Serum PIVKA-II Measurement

BACKGROUND: The serum des-gamma-carboxyprothrombin (protein induced by vitamin K antagonist-II, PIVKA-II) is a useful tumor marker in addition to alpha-fetoprotein for diagnosing primary hepatocellular carcinoma (HCC). In this study, we evaluated the laboratory performance of a modified ELISA method for PIVKA-II measurement adopting an automated ELISA processor in comparison with conventional manual method and investigated its diagnostic performance in patients with HCC. METHODS: The laboratory performance of modified ELISA using PIVKA-II ELISA kit (Sanko Junyaku Co., Japan) was evaluated using control materials (10, 25, 500, 1,000 mAU/mL) and 208 patient samples according to the CLSI guidelines. In 93 HCC patients and 88 disease controls (30 chronic hepatitis and 58 liver cirrhosis), ROC curve, sensitivity, specificity, and positive and negative predictive values were analyzed. RESULTS: Total and within-run CVs for middle, high and very high level samples were less than 10%, while those of low level samples were over 10% (12.6% and 11.7%, respectively). The modified ELISA showed an excellent linearity (r>0.99) and low carryover rate (-0.14%). Although the correlation between the conventional and modified ELISAs was excellent (r=0.982), there was a proportional deviation of PIVKA-II levels (y intercept: 0.621). With a cut-off of 30 mAU/mL, the sensitivity and specificity of PIVKA-II for the diagnosis of HCC were 58% and 92%, respectively. CONCLUSIONS: PIVKA-II measurement by modified ELISA using an automated ELISA processor can improve the efficiency of laboratory in terms of turnaround time and labor intensiveness while maintaining reasonable sensitivity and specificity for the diagnosis of HCC.

Mycobacterial Infection after Intravesical Bacillus Calmette-Guerin Treatment for Bladder Cancer: A Case Report / 대한진단검사의학회지

Bacillus Calmette-Guerin (BCG) has been traditionally used as a vaccine against tuberculosis. Further, intravesical administration of BCG has been shown to be effective in treating bladder cancer. Although BCG contains a live attenuated strain of Mycobacterium bovis, complications such as M. bovis BCG infection caused by BCG administration are extremely rare. Here, we report a case of BCG infection occurring after intravesical BCG therapy. A 67-yr-old man presented with azotemia and weight loss. He had been diagnosed with bladder cancer 4 yr back, and had undergone transurethral resection of the bladder tumor and intravesical BCG (Tice strain) therapy at that time. An acid-fast bacterial strain was isolated from his urine sample. We did not detect Mycobacterium tuberculosis protein 64 (MPT-64) antigen in the isolates obtained from his sample, and multiplex PCR and PCR-reverse blot hybridization assay indicated that the isolate was a member of the M. tuberculosis complex, but was not M. tuberculosis. Finally, sequence analysis of 16S ribosomal RNA and DNA gyrase, subunit B (gyrB) suggested that the organism was M. bovis or M. bovis BCG. Although we could not confirm that M. bovis BCG was the causative agent, the results of the 3 molecular methods and the MPT-64 antigen assay suggest this finding. This is an important finding, especially because M. bovis BCG cannot be identified using common commercial molecular genetics tools.

Discrepancy in Genotyping of Apolipoprotein E between Allele-Specific PCR and Fluorescence Resonance Energy Transfer or Sequencing / 대한진단검사의학회지

The human apolipoprotein E (APOE) gene contains several single-nucleotide polymorphisms (SNPs) that are distributed across the gene. The genotype of the APOE gene has important implications as a risk factor for various diseases. We observed 2 cases in which the results of allele-specific PCR (AS-PCR) of the APOE gene were not consistent with those of fluorescence resonance energy transfer (FRET) or sequencing analysis. In these cases, genotyping by AS-PCR showed that patients were epsilon2 homozygotes, while sequencing analysis and FRET showed that they were epsilon2/epsilon3 heterozygotes. Herein, we describe the causes of the errors in genotyping and describe the significance of these errors.

Congenital Zinc Deficiency from Mutations of the SLC39A4 Gene as the Genetic Background of Acrodermatitis Enteropathica

Acrodermatitis enteropathica (AE) is an autosomal recessive disorder with the clinical triad of acral dermatitis, diarrhea and alopecia. AE is known to be caused by mutations of the SLC39A4 gene on the chromosome band 8q24.3, encoding the zinc transporter in human. An 8-month-old Korean boy presented with eczematous changes on the inguinal area and knees and was diagnosed with AE. Blood tests revealed a markedly decreased level of plasma zinc, and his symptoms improved on oral zinc replacement. To confirm the diagnosis of AE from congenital zinc deficiency, direct sequencing analysis of SLC39A4 was performed and revealed that he was compound heterozygous for a known missense mutation (Arg95Cys) and a novel splicing mutation in the donor site of intron 7 (c.1287+2T>C). Family study showed that his parents were heterozygous carriers of the mutations. To the best of our knowledge, this is the first report of genetically confirmed AE in Korea.

Sequence Variations and Haplotypes of the GJB2 Gene Revealed by Resequencing of 192 Chromosomes from the General Population in Korea

OBJECTIVES: Hearing impairment (HI) is the most common sensory deficit in human. The Gap Junction Protein, Beta-2 (GJB2) gene encodes the protein connexin 26, and this gene accounts for up to half of the cases of autosomal recessive nonsyndromic HI. This study was conducted to obtain a set of sequence variations (SVs) of the GJB2 gene among Koreans from the general population for making molecular genetic diagnoses and performing genetic counseling. METHODS: We resequenced the GJB2 gene in 192 chromosomes from 96 adult individuals of Korean descent and who were without a history of hearing difficulty. The data of the SVs was obtained and the haplotypes were reconstructed from the data. RESULTS: Five SVs were observed, including a novel one (c.558G>A; p.T186T), with the allele frequencies ranging from 0.5% (1/192) to 41% (79/192). The linkage disequilibrium study and haplotype construction showed that some of the SVs are in tight linkage, resulting in a limited number of haplotypes. CONCLUSION: We observed SVs of the GJB2 gene with different allele frequencies, and a limited number of haplotypes were constructed. The data from this study can be used as reference data for GJB2-related hearing genetic studies, including studies on the founder effect and population genetics, and this data is particularly relevant to people of East Asian decent.

A comparative study of electric and manual toothbrushes on oral hygiene status in fixed orthodontic patients / 대한치과교정학회지

Patients with fixed orthodontic appliances frequently have increased levels of plaque accumulation leading to the possibility of gingivitis or enamel decalcification. Although many methods may be helpful in reducing dental plaque formation, the optimal mechanical removal of plaque is the most important factor during orthodontic treatment. The purpose of this study was to evaluate the efficacy of an electric toothbrush (with a specially designed orthodontic brush head) compared to a manual toothbrush in controlling plaque and gingivitis for patients with fixed orthodontic appliances. Oral hygiene status was measured in thirty-four patients using a plaque index, a gingival index and a bleeding index, before and four weeks after the attachment of fixed orthodontic appliances. Patients were randomly divided into two groups: electric and manual toothbrush groups. Oral hygiene instruction was given according to the type of toothbrush used. The Braun Oral-B D9511 with Braun Oral-B Ortho OD 15-1 brush head was used as the electric toothbrush while the Butler G.U.M. 124 was given as the manual toothbrush. After four and eight weeks, oral hygiene status was measured again. Through a comparison between the electric and the manual toothbrush groups, the following results were obtained. 1. All oral hygiene indices showed an increasing tendency after four weeks of fixed orthodontic appliance. 2. All indices presented a decreasing tendency four and eight weeks after oral hygiene instruction. 3. In case of the gingival index and bleeding index, the decreasing tendency did not show a statistically significant difference between the electric and the manual toothbrush groups. 4. The decreasing tendency of plaque index presented a statistically significant difference between the two groups, showing that the electric toothbrush was more effective in terms of oral hygiene. These findings suggest that an electric toothbrush is useful to orthodontic patients with fixed appliances.

Combination chemotherapy with TAD(6-thioguanine, Ara-C and daunorubicin) in acute myelogenous leukemia / 대한혈액학회지

No abstract available.