Sam Im Choi

Determination of human angiotensin converting enzyme (ACE) gene polymorphisms in erectile dysfunction : Frequency differences of ACE gene polymorphisms according to the method of analysis

Abstract The D polymorphism of angiotensin converting enzyme (ACE) gene has been found to be associated with various diseases, and ACE may also be involved in the pathogenesis of erectile dysfunction. On the other hand, interpretation of the data on the association of DD genotype with various diseases is controversial, due to methodological and technical variations in detection of the polymorphisms. We investigated a possible association between the DD genotype and erectile dysfunction in a Korean population, and compared the frequency of ACE genotypes using our multiplexed PCR method with those based on the conventional PCR method in a sample of erectile dysfunctional and control subjects. There was significant difference in the distribution of ACE genotypes between the erectile dysfunctional (conventional PCR) and the control subjects (multiplexed PCR) (χ2=7.395, p<0.05), but there was no significant difference in the distribution of the genotypes between both groups (χ2=0.815, p<0.05) when our multiplexed PCR method was used. Therefore our results suggest that especially the conventional PCR method for ACE gene polymorphism may require careful control and may need repeated testing to verify the insertion deletion (ID) heterozygotes, and that a multiplexed PCR method can markedly increase the detection rate of the I allele in ID heterozygotes. No association was found between I/D polymorphism and erectile dysfunctional subjects in the Korean population studied.

Absence of antibody to cyclic citrullinated peptide in sera of non-arthritic patients with chronic hepatitis B virus infection

The objective of this study was to investigate if antibody to cyclic citrullinated peptide (anti-CCP) is detected in sera of patients with chronic hepatitis B virus (HBV) infection. Serum anti-CCP and IgA, IgG, and IgM rheumatoid factor (RF) isotypes were measured by enzyme-linked immunosorbent assay on 176 non-arthritic patients with HBV infection. IgA RF, IgG RF, and IgM RF were detectable in 29.5, 21, and 18.8% of the tested sera, respectively, with a total seropositivity rate of 42.7%. Marginally elevated anti-CCP was detected in one patient (0.6%). By regression analysis, there was no statistically significant association between the serum levels of anti-CCP and serum IgA, IgG, or IgM RF (R2 = 0.033, with respective p values of 0.224, 0.297, and 0.334). In conclusion, anti-CCP was rarely detected in non-arthritic patients with HBV infection in contrast to RF. Thus, testing for anti-CCP may be a useful tool for the diagnosis of rheumatoid arthritis in this population.

A case of 49,XXXXX in which the extra X chromosomes were maternal in origin.

This report describes an 11 month old female baby with features of pentasomy X. A molecular and cytogenetic evaluation revealed that her karyotype was 49,XXXXX and her extra X chromosomes were of maternal origin. She has muscular hypotonia, mental retardation, a cleft palate, mild hydrocephalus as a result of dilatation of both lateral ventricles, hyperextensible elbow joints, proximal radioulnar synostosis, clinodactyly of the fifth finger, valgus of the feet, and small hands and feet. In addition, she has a persistent pupillary membrane and congenital chorioretinal atrophy. The pathogenesis of pentasomy X is not clear at present, but it is thought to be caused by successive maternal non-dysjunctions.

Reference intervals for whole blood viscosity using the analytical performance-evaluated scanning capillary tube viscometer

OBJECTIVES This study was performed to establish the reference intervals for whole blood viscosity (WBV) using the analytical performance-evaluated scanning capillary tube viscometer (SCTV). DESIGN AND METHODS The analytical performance of the SCTV was evaluated using three different levels of QC materials and sixty human EDTA-blood samples. To establish the reference intervals for WBV, 297 healthy individuals (123 men and 174 women) were selected from 1083 subjects. RESULTS Within-day precisions with QC materials and human whole blood and between-day precisions with QC materials were below 5.0%, 6.6% and 8.0% in CVs at all shear rates, respectively. Comparison tests between the SCTV and the Brookfield viscometer showed a significant correlation (R(2)=0.972, p<0.001). The reference intervals for WBV in healthy men were 3.66-5.41cP at 300s(-1) and 23.15-36.45cP at 1s(-1) while those in women were 3.27-4.32cP at 300s(-1) and 18.20-27.36cP at 1s(-1), respectively. CONCLUSIONS Using the analytical performance-evaluated SCTV, the reference intervals for WBV were established in healthy adults, which could be beneficial to the clinical utility of WBV in the aspect of appropriate modalities for the improvement of blood viscosity.

Concentrations of Blood Vitamin A, C, E, Coenzyme Q10 and Urine Cotinine Related to Cigarette Smoking Exposure

BACKGROUND In smokers, smoking causes many disease entities including cancers, chronic pulmonary diseases and cardiovascular diseases. Passive smoking is also accepted as a carcinogen and its adverse health effects are emphasized. We measured blood vitamin A, C, E (alpha-, beta- and gamma-tocopherol), coenzyme Q10 and urine cotinine concentrations in nonsmokers and smokers. METHODS Twenty-one healthy nonsmokers and 24 healthy smokers were included in this study. Smoking status was assessed with a self-reported questionnaire. Plasma was analyzed for coenzyme Q10 and serum for vitamin A, C, E using HPLC (Agilent Technologies Inc., USA) and random urine for cotinine using LC/tandem mass spectrometry (Applied Biosystems Inc., Canada). RESULTS Smokers had significantly lower serum concentrations of vitamin C than nonsmokers (P=0.0005). No significant differences in concentrations of serum vitamin A, E, and plasma coenzyme Q10 were observed. Smokers had highly elevated urine cotinine levels (1,454+/-903 ng/mL). In 16 (76.2%) of 21 nonsmokers, urine cotinine was detected (3.25+/-4.08 ng/mL). The correlations between urine cotinine and blood antioxidants levels were not found. Neither, the correlation between smoking status and blood antioxidants & urine cotinine was found. CONCLUSIONS This study shows that smokers had significantly lower vitamin C levels among nonenzymatic antioxidants, namely, vitamin A, C, E and coenzyme Q10. High detection rate of urine cotinine in nonsmokers show the seriousness of passive smoking exposure, therefore more social efforts should be directed to reduce passive smoking exposure.

MYC Rearrangement Involving a Novel Non-immunoglobulin Chromosomal Locus in Precursor B-cell Acute Lymphoblastic Leukemia

MYC rearrangement, a characteristic cytogenetic abnormality of Burkitt lymphoma and several subsets of other mature B-cell neoplasms, typically involves an immunoglobulin gene partner. Herein, we describe a case of precursor B-cell lymphoblastic leukemia harboring a MYC rearrangement with a novel non-immunoglobulin partner locus. The patient was a 4-yr-old Korean boy with ALL of the precursor B-cell immunophenotype. At the time of the second relapse, cytogenetic analyses revealed t(4;8)(q31.1;q24.1) as a clonal evolution. The MYC rearrangement was confirmed by FISH analysis. He died 3 months after the second relapse without achieving complete remission. To our knowledge, this is the first report of a case of MYC rearrangement with a non-immunoglobulin partner in precursor B-cell lymphoblastic leukemia.

Molecular Genetic Analysis of the Ryanodine Receptor Gene (RYR1) in Korean Malignant Hyperthermia Families

BACKGROUND Malignant hyperthermia (MH) is genetically heterogeneous, with mutations in the gene encoding the skeletal muscle ryanodine receptor (RYR1) at 19q13.1 accounting for up to 80% of the cases. However, the search for known and novel mutations in the RYR1 gene is hampered by the fact that the gene contains 106 exons. We aimed to analyze mutations from the entire RYR1 coding region in Korean MH families. METHODS We investigated seven affected MH individuals and their family members. The entire RYR1 coding region from the genomic DNA was sequenced, and RYR1 haplotyping and mutational analysis were carried out. RESULTS We identified nine different RYR1 mutations or variations from seven Korean MH families. Among these, five previously reported mutations (p.Gly248Arg, p.Arg2435His, p.Arg2458His, p.Arg2676Trp, and p.Leu4838Val) and four novel variations of unknown significance (p.Arg2508Cys, p.Met4022Val, p.Glu2669Lys, and p.Ala4295Val) were identified. In two families, two variations (R2676W & M4022V, R2435H & A4295V, respectively) were identified simultaneously. Four of the observed nine mutations or variations were located outside the hotspot region of RYR1 mutations. CONCLUSIONS These data indicate that RYR1 is a main candidate gene in Korean MH families, and that comprehensive screening of the entire coding sequence of the RYR1 gene is necessary for molecular genetic investigations in MH-susceptible individuals, owing to the presence of RYR1 mutations or variations outside of the hotspot region.

JAK2 V617F and Exon 12 Genetic Variations in Korean Patients with BCR/ABL1-negative Myeloproliferative Neoplasms

BACKGROUND JAK2 genetic variations have been described in a high proportion of patients with BCR/ABL1-negative myeloproliferative neoplasms (MPN). This study was designed to analyze the frequencies of JAK2 V617F and exon 12 variations, and their correlations with clinical characteristics of Korean patients with BCR/ABL1-negative MPN. METHODS We examined a total of 154 patients with BCR/ABL1-negative MPN that included 24, 26, 89, and 15 patients with polycythemia vera (PV), primary myelofibrosis (PMF), essential thrombocythemia (ET), and unclassified myeloproliferative neoplasms (MPNU), respectively. We performed allele-specific PCR to detect V617F in all BCR/ABL1-negative patients, and performed direct sequencing to detect exon 12 variations in 47 V617F-negative MPN patients. JAK2 c.1641+179_183del5 variation was detected by restriction fragment length polymorphism assay in 176 healthy subjects. RESULTS JAK2 V617F was detected in 91 patients (59.1%): PV (91.6%), PMF (46.2%), ET (52.8%), and MPNU (66.7%). In V617F-negative MPN patients, no mutations were found in exon 12. The c.1641+179_183del5 was detected in 68.1% of V617F-negative MPN patients and 45.4% of healthy subjects (P=0.008). JAK2 V617F was closely correlated with age and leukocytosis in BCR/ABL1-negative MPN patients (P<0.05). However, c.1641+179_183del5 was not related to age, sex, or complete blood cell count parameters in V617F-negative MPN patients and healthy subjects. The c.1641+179_183del5 was associated with an increased odds ratio for MPN (odds ratio, 2.6; 95% confidences interval, 1.3-5.1; P=0.007). CONCLUSIONS Frequencies of V617F are similar to reported results. JAK2 exon 12 mutations may be rare and c.1641+179_183del5 may influence the occurrence of MPN in Korean patients with V6 17F-negative MPN.

Concurrence of e1a2 and e19a2 BCR-ABL1 Fusion Transcripts in a Typical Case of Chronic Myeloid Leukemia

Dear Editor, There are three types of BCR-ABL1 fusion transcripts that differ on the basis of the breakpoint in the BCR gene [1]. The major type, encoding p210, has two isoforms, b2a2 (e13a2) and b3a2 (e14a2), and is associated with more than 95% of Ph-positive CML cases. The minor type, encoding p190, is e1a2. The micro type, encoding p230, is e19a2. This micro type is rare, and has been associated with a variety of hematologic malignancies including neutrophilic CML (CML-N), all phases of classical CML, essential thrombocythemia (ET), and acute myeloid or lymphoblastic leukemia [2, 3]. Here, we describe the first case of chronic phase CML concurrently expressing e1a2 and e19a2 BCR-ABL1. An 89-year-old woman was referred to our hospital for evaluation of her leukocytosis. She appeared ill, but had no splenomegaly. The complete blood count (CBC) revealed 137.46× 10/L WBC, 10.0 g/dL Hb, and 194×10/L platelets. The blood smear demonstrated 3% blasts, basophilia, and eosinophilia, and bone marrow (BM) aspirate showed a hypercellularity (Fig. 1). The karyotype in BM was 46,XX,t(9;22)(q34;q11.2) [20] and the FISH result using an LSI BCR/ABL probe (Abbott Molecular Inc., Des Plaines, IL, USA) was nuc ish (ABLx3),(BCRx3),(ABL con BCRx2)[200/200]. JAK2 mutation was not detected. The commercial multiplex reverse transcription (RT)-PCR (HemaVision, DNA Diagnostic, Risskov, Denmark) result was positive for BCR/ABL in Master M6 and Split-out M6B PCR, and presented as an atypically thick band overlapping with the control band at 911 bp (Fig. 2A). Additional sequencing from the M6B amplicon revealed the BCR-ABL1 fusion was the micro type (e19a2) (Fig. 2B). Another real-time quantitative PCR for the minor BCR-ABL1 rearrangement indicated positivity (0.04, normalized copy number [NCN]), which was confirmed by sequencing (Fig. 2C). Therefore, it was determined that the patient had a BCR-ABL1 fusion consisting predominantly of the micro isoform (e19a2) with a small amount of the minor isoform (e1a2). The concurrence of those two isoforms might occur as a result of alternative splicing of the primary BCR-ABL1 fusion transcript [4]. The patient could not start any targeted therapy owing to her poor performance status and the potential interaction with her ongoing risperidone treatment. Only hydroxyurea (500 mg/day) was initiated. One month later, her WBC count decreased to 14.23 ×10/L. After 6 months, she showed no complications and her WBC count was 16.60×10/L. The e19a2 BCR-ABL1 fusion transcript can be associated

Concurrence of ring 21 and trisomy 21 in children of normal parents.

We present a case of two siblings with different chromosome 21 abnormalities that are both de novo [r(21)/i(21p13) mosaicism and rob(14;21)]. Molecular studies using polymorphic markers have shown that these two aberrations had a common maternal origin. However, the parents were cytogenetically and phenotypically normal. This unusual association has not been reported and is considered to be a unique case that should be addressed.