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Objective With the recent reports of additional alleles of the CYP2C19 gene with decreased or no function, the clinical utility of real-time polymerase chain reaction (PCR)-based testing that detects only a small number of variant targets needs to be evaluated. Method We retrospectively reviewed 7-year data for real-time PCR test records from a single hospital and analyzed CYP2C19 genotypes from publicly available whole-genome or whole-exome data from a healthy Korean population. Results Of the 2327 test results in this hospital, the *1 allele was most common (60.5%), followed by *2 (28.0%), *3 (10.1%), and *17 (1.4%). Among 5305 healthy Korean individuals, the frequencies of the *2, *3, and *17 alleles were 28.6%, 9.9%, and 1.0%, respectively, which were not statistically different from those of the hospital data (P =.4439, P =.6025, and P =.1142, respectively). Interestingly, the total frequency of additional nonfunctional alleles (*4, *6, *22, and *24) that could not be detected using real-time PCR was only 0.1%, with a total allele count of 8. Conclusion Our study shows that the clinical utility of real-time PCR for CYP2C19 genotyping remains satisfactory. However, caution should be exercised because the test can miss patients with decreased CYP2C19 function. [ABSTRACT FROM AUTHOR]

Few studies have reported on delta checks for tumour markers, even though these markers are often evaluated serially. Therefore, this study aimed to establish a practical delta check limit in different clinical settings for five tumour markers: alpha-fetoprotein, cancer antigen 19-9, cancer antigen 125, carcinoembryonic antigen, and prostate-specific antigen. Pairs of patients' results (current and previous) for five tumour markers between 2020 and 2021 were retrospectively collected from three university hospitals. The data were classified into three subgroups, namely: health check-up recipient (subgroup H), outpatient (subgroup O), and inpatient (subgroup I) clinics. The check limits of delta percent change (DPC), absolute DPC (absDPC), and reference change value (RCV) for each test were determined using the development set (the first 18 months, n=179,929) and then validated and simulated by applying the validation set (the last 6 months, n=66,332). The check limits of DPC and absDPC for most tests varied significantly among the subgroups. Likewise, the proportions of samples requiring further evaluation, calculated by excluding samples with both current and previous results within the reference intervals, were 0.2–2.9% (lower limit of DPC), 0.2–2.7% (upper limit of DPC), 0.3–5.6% (absDPC), and 0.8–35.3% (RCV99.9%). Furthermore, high negative predictive values >0.99 were observed in all subgroups in the in silico simulation. Using real-world data, we found that DPC was the most appropriate delta-check method for tumour markers. Moreover, Delta-check limits for tumour markers should be applied based on clinical settings. [ABSTRACT FROM AUTHOR]

Alterations of the FLT3 gene, in the form of internal tandem duplications (ITD) and D835 point mutations, occur frequently in acute promyelocytic leukemia (APL). We therefore evaluated the frequency and clinical relevance of FLT3 aberrations in a series of Korean APL patients. We assayed FLT3 ITD and D835 mutation status in 75 newly diagnosed APL patients and we correlated the presence of these mutations with clinical parameters and outcomes. Of the 75 patients, fifteen (20.0%) carried FLT3 mutations, nine (12.0%) with FLT3 ITD, seven (9.3%) with D835 mutations and one with both types. Patients presenting with higher leukocyte counts (>10×109/L) had a significantly higher frequency of FLT3 ITD (P = 0.030). There was no association between FLT3 aberrations and other clinicohematologic features including age, gender, M3 variant morphology and PML/RARα subtype. Death at presentation before induction chemotherapy was significantly more frequent in patients with ITD than in those without ITD (33.3% vs. 4.5%, P = 0.020), but was not significantly related to the presence of D835 mutations (28.6% vs. 5.9%, P = 0.094). Both ITD and D835 mutations were associated with shortened event-free survival (P = 0.048 and P = 0.029, respectively), but there was no correlation between disease-free survival among the 61 patients who achieved complete remission and the presence of FLT3 mutations (P = 0.543 for ITD and P = 0.277 for D835). FLT3 mutations were less frequent in Korean APL patients than in Western APL patients. In Korean patients, however, FLT3 mutations were associated with higher leukemic burdens and early deaths before remission resulting in inferior prognosis. [ABSTRACT FROM AUTHOR]

Abstract: Sixty percent to 80% of Clostridium difficile isolates in Korea have been reported to be toxigenic. However, over 1 year, we encountered a high number of tcdA−tcB+ strains associated with pseudomembranous colitis (PMC). C. difficile was isolated from 224 of 471 specimens (47.6%) from 371 patients. A subset of the culture-positive specimens (n = 106), containing no duplicate cases, was randomly selected for tcdA and tcdB polymerase chain reaction (PCR) assays. PCR results showed that tcdA+tcdB+ and tcdA−tcdB+ strains accounted for 39.6% (42/106) and 50.9% (54/106), respectively. Endoscopy, performed on 55/106 patients, revealed 29 with PMC, 5 with colitis, 14 with other colon diseases, and 7 normal cases. Among the 29 PMC cases, 21 (72.4%) were associated with tcdA−tcdB+ strains (P = 0.0016). These results revealed the possible emergence of tcdA−tcdB+ C. difficile strains in Korea, and these variant strains could evoke a higher rate of PMC than tcdA+tcdB+ strains. [Copyright &y& Elsevier]

Background: National reference standards for anti-HIV-1 antibody are needed to evaluate the performance and maintain the quality control of anti-HIV-1 antibody assays. The aim of this study was to prepare a mixed-titer performance panel and assess its suitability as a national reference standard for anti-HIV-1 antibody according to stability, collaboration, and other studies., Methods: Nineteen serum samples from different HIV patients were obtained, along with 15 units of fresh frozen plasma samples with negative anti-HIV-1 antibody results. Ten anti-HIV-1 antibody-positive candidate standards and two negative candidate standards were prepared based on the reactivity in the Alinity i HIV Ag/Ab combo assay (Abbott Laboratories, Wiesbaden, Germany). A collaborative study was conducted across eight laboratories using five anti-HIV-1 antibody assays. Real-time and accelerated stability were evaluated to assess the long-term stability., Results: In the collaborative study, results of all five anti-HIV-1 antibody assays were positive for all 10 candidate standards prepared using HIV patient samples. The CV of each assay for every candidate standard was within 10%, except for one assay result. No real-time and accelerated stability change trend was observed at -70°C or -20°C, supporting that the reference standards were maintained in a stable state at -70°C for long-term storage., Conclusions: The overall results suggest that the 12 candidate standards could serve as national reference standards for anti-HIV-1 antibody.

Background and Objectives : High-sensitivity cardiac troponin I (hs-TnI) is an important indicator of acute myocardial infarction (AMI) among patients presenting with chest discomfort at the emergency department (ED). We aimed to determine a reliable hs-TnI cut-off by comparing various values for a baseline single measurement and an algorithmic approach. Materials and Methods : We retrospectively reviewed the hs-TnI values of patients who presented to our ED with chest discomfort between June 2019 and June 2020. We evaluated the diagnostic accuracy of AMI with the Beckman Coulter Access hs-TnI assay by comparing the 99th percentile upper reference limits (URLs) based on the manufacturer's claims, the newly designated URLs in the Korean population, and an algorithmic approach. Results : A total of 1296 patients who underwent hs-TnI testing in the ED were reviewed and 155 (12.0%) were diagnosed with AMI. With a single measurement, a baseline hs-TnI cut-off of 18.4 ng/L showed the best performance for the whole population with a sensitivity of 78.7%, specificity of 95.7%, negative predictive value (NPV) of 97.1%, and positive predictive value (PPV) of 71.3%. An algorithm using baseline and 2-3 h hs-TnI values showed an 100% sensitivity, 97.7% specificity, an NPV of 100%, and a PPV of 90.1%. This algorithm used a cut-off of <4 ng/L for a single measurement 3 h after symptom onset or an initial level of <5 ng/L and a change of <5 ng/L to rule a patient out, and a cut-off of ≥50 ng/L for a single measurement or a change of ≥20 ng/L to rule a patient in. Conclusions : The algorithmic approach using serial measurements could help differentiate AMI patients from patients who could be safely discharged from the ED, ensuring that patients were triaged accurately and did not undergo unnecessary testing. The cut-off values from previous studies in different countries were effective in the Korean population.

Background and Objectives : Risk management is considered an integral part of laboratory medicine to assure laboratory quality and patient safety. However, the concept of risk management is philosophical, so actually performing risk management in a clinical laboratory can be challenging. Therefore, we would like to develop a sustainable, practical system for continuous total laboratory risk management. Materials and Methods : This study was composed of two phases: the development phase in 2019 and the application phase in 2020. A concept flow diagram for the computerized risk registry and management tool (RRMT) was designed using the failure mode and effects analysis (FMEA) and the failure reporting, analysis, and corrective action system (FRACAS) methods. The failure stage was divided into six according to the testing sequence. We applied laboratory errors to this system over one year in 2020. The risk priority number (RPN) score was calculated by multiplying the severity of the failure mode, frequency (or probability) of occurrence, and detection difficulty. Results : 103 cases were reported to RRMT during one year. Among them, 32 cases (31.1%) were summarized using the FMEA method, and the remaining 71 cases (68.9%) were evaluated using the FRACAS method. There was no failure in the patient registration phase. Chemistry units accounted for the highest proportion of failure with 18 cases (17.5%), while urine test units accounted for the lowest portion of failure with two cases (1.9%). Conclusion : We developed and applied a practical computerized risk-management tool based on FMEA and FRACAS methods for the entire testing process. RRMT was useful to detect, evaluate, and report failures. This system might be a great example of a risk management system optimized for clinical laboratories.

Background: Neurofibromatosis (NF) is a genetic disorder, and neurofibromatosis types 1 and 2 have different genetic and clinical features. Herein, we present the clinical and genetic aspects of a patient carrying a constitutional NF1 gene mutation and whose neurocutaneous manifestations suggested a NF type 2 (NF2)., Methods: A 55-year-old woman presented with headache and deterioration of vision. Physical examination and radiologic findings revealed multiple subcutaneous nodules and multiple intracranial and spinal masses which were suspected to be NF2., Results: Genomic DNA sequencing using a peripheral blood sample revealed a splicing mutation in the NF1 gene. Tumor resection and biopsy revealed intracranial meningiomas and paraspinal Schwannoma compatible with NF2. PCR-direct sequencing using tumor tissue samples showed pathogenic somatic mutation of the NF2 gene., Conclusions: We report a case of NF2 presenting with a pathogenic somatic mutation in the NF2 gene in a woman harboring a germline splicing mutation in the NF1 gene. This case emphasizes the importance of sequence analy¬sis by using tumor tissues and the need to elucidate the role of a NF1 splicing mutation.

Background: The Norudia glycated albumin (GA) assay was evaluated for analytical performance and assay applicability on multiple analytical platforms., Methods: The evaluation included precision, linearity, reference interval, and comparison with Lucica GA assay. A multicenter study was conducted to compare the results of Norudia GA assay on five kinds of widely used automated clinical chemistry analyzers., Results: Within-laboratory imprecisions for GA% presented 1.3 - 3.3% and 0.8 - 2.6% for low- and high-level control materials, respectively, on different analyzers. GA assay was linear from 20.0 to 680.0 µmol/L of GA. The claimed reference range (12 - 16 GA%) was verified. Norudia GA showed a good GA% correlation with Lucica GA (correlation coefficient 0.999). GA% from each analyzer showed good correlation with the consensus mean of the results of five analyzers (correlation coefficient 0.997 - 0.999)., Conclusions: The Norudia GA assay can successfully be implemented in all the tested platforms, with good GA% correlation.

Background and objectives: For proper antimicrobial therapy, cumulative antibiograms should be representative of geographic region and be accurate. Clinical and Laboratory Standards Institute (CLSI) guidelines recommend that only the first isolates (FI) of a species per patient are used when reporting cumulative antibiograms. However, >50% of hospitals in the United States report antibiograms of all isolates. We compared antibiograms from the FI with those from total isolates (TI). Materials and Methods: Antimicrobial data of all isolates identified in the Microbiology unit of Ilsan Paik Hospital in 2019 were retrospectively acquired from the hospital information system. The susceptibility rates to antimicrobials of Escherichia coli , Acinetobacter baumannii , Klebsiella pneumoniae , Pseudomonas aeruginosa , Staphylococcus aureus , Enterococcus faecium , and Enterococcus faecalis were analyzed by FI and TI, respectively. Isolate counts and susceptibility rates of each species for the reported antimicrobials were compared. Results: The numbers of isolates by FI/TI were as follows: 1824/2692 E. coli , 480/1611 A. baumannii , and 662/1306 K. pneumoniae , and 407/953 P. aeruginosa for gram-negative bacteria and 649/1364 S. aureus , 211/313 E. faecium , and 323/394 E. faecalis for gram-positive bacteria. All antimicrobial agents showed higher susceptibility rates when calculated as FI than as TI in gram-negative bacteria except colistin: 3.7% for E. coli , 14.5% for A. baumannii , 8.3% for K. pneumoniae , and 7.9% for P. aeruginosa . In S. aureus , 8/11 antimicrobial agents revealed higher susceptibility rates for FI than for TI. E. faecalis and E. faecium showed lower susceptibility rates for 7/10 antimicrobial agents for FI than for TI. The oxacillin susceptibility rates of S. aureus were 36.6%/30.2% with FI/TI and vancomycin susceptibility rates for E. faecium were 54.1% and 49.5%, respectively. Conclusions: When comparing cumulative antibiograms by FI with TI using real-world data, there is a large gap for critical species requiring hospital infection control. Although FI calculation is difficult, antibiograms must be calculated as FI for proper preemptive antimicrobial therapy because FI provides proper antimicrobial susceptibility data.

Background: Preanalytical errors cause a decrease in the accuracy of clinical laboratory results. We analyzed preanalytical errors (preAEs) made in the clinical laboratory of a university hospital., Methods: All samples received in a centralized laboratory from January 1, to December 31, 2018, were analyzed retrospectively. The categories of preAEs were improper request, incorrect labeling, improper collection/transport, inadequate sample volume, inappropriate container, hemolysis, and sample clotting. The rates of preAEs in these categories were calculated according to sample type, laboratory subunit, department, sampling place, sampling time, and patient age., Results: Of 1,082,014 samples received and analyzed by the laboratory, 6,848 (0.63%) were classified as having preAEs. The most frequent categories of preAE were hemolysis (44.6%), sample clotting (30.8%), and inadequate volume (16.7%). The most frequent preAE category for whole-blood and serum/plasma was clotting and hemolysis, respectively. The most frequent preAE category in the blood bank, clinical chemistry, immunology, and test referral service laboratory subunits was hemolysis, in the hematology subunit it was sample clotting, and in the microbiology and urinalysis subunits it was inadequate sample volume. Surgical departments had a higher rate of preAEs than did non-surgical departments (p < 0.0001). Samples drawn in the sampling room showed the lowest frequencies of preAEs (0.01%). Samples drawn on general wards from 5 pm to 5 am, when duty nurses perform sampling, showed a preAE rate of 2.80%. The rate of preAEs increased with patient age., Conclusions: This analysis of preAEs is the most comprehensive to date. Our findings will promote the provision of high-quality laboratory services to clinicians and their patients.

Objective: Frequent false-positive results of current HIV screening occur due to its high sensitivity. These false-positives may delay subsequent clinical decision making. In this study, we aim to determine the usefulness of additional immunochromatographic assay (ICA) in hospitals using fourth-generation HIV-1/2 Ag/Ab assays followed by western blot (WB) confirmation., Methods: Overall, 158,431 patients' sera were screened for HIV using a fourth-generation HIV-1/2 Ag/Ab assays (Elecsys HIV combiPT) from July 2011 to May 2019. All 401 ECLIA-positive sera were re-tested using an ICA kit (SD Bioline HIV1/2 3.0 ICA), followed by WB confirmation according to national policy., Results: Sixty-five ECLIA-positive samples (65/401, 16.2%) were positive for ICA, 96.9% (63/65) of which were confirmed positive using WB. ICA results were negative in 83.8% (336/401) of ECLIA-positive samples, of which 98.5% (331/336) remained negative on WB. Five specimens (1.5%) from patients with symptoms consistent with acute HIV syndrome were false negatives on ICA. These false negatives were confirmed positive using a p24 antigen assay and nucleic acid test (NAT)., Conclusions: ICA for anti-HIV Ab screen-positive specimens is helpful for earlier medical decision considering frequent false-positive results on screening. Nonetheless, ICA might be negative in acute HIV syndrome, necessitating p24 Ag assay or NAT with shorter window periods., (© 2020 by the Association of Clinical Scientists, Inc.)

We investigated the frequency and clinical significance of macrolide resistance in adult and pediatric patients with community-acquired pneumonia from a Mycoplasma pneumoniae infection. The frequency of the A2063G mutation in the 23S rRNA gene was significantly higher in children than in adults (61.3% [19/31] and 13.3% [8/60], respectively; P < 0.001). Patients with macrolide-resistant M. pneumoniae infections showed a longer duration of fever (P = 0.021) and required a longer duration of antibiotic treatment (P = 0.007).

We evaluated the performances of 2 PCR assays (BD GeneOhm and Seegene ACE) for direct detection of tcdB from stool specimens. The concordance rate between BD and Seegene was 96.3%. The sensitivities, specificities, positive predictive values (PPVs), and negative predictive values (NPVs) of BD and Seegene were 95.7%, 96.5%, 91.8%, and 98.2% and 90.0%, 97.1%, 92.6%, and 96.0%, respectively.

FLT3 mutations are common genetic changes, and are reported to have prognostic significance in acute myeloid leukemia (AML). The FLT3 internal tandem duplication (ITD) and the D835 activating mutation in the tyrosine kinase domain (TKD) were analyzed by polymerase chain reaction (PCR) in the genomic DNA of Korean patients with AML at diagnosis and during follow-up. There were 226 patients with AML enrolled between March 1996 and August 2005. The incidence of ITD and TKD at diagnosis was 13% (29/226) and 3% (6/226). When compared to Western and other Asian patients with AML, Korean patients had a lower frequency by about two-thirds of ITD and TKD. Among the non-M3 cases (N=203), the patients with an ITD had a significantly shorter event-free survival when compared with those without an ITD (p=0.0079). Among 54 relapsed patients, 9 patients had the FLT3 ITD at diagnosis. Six patients demonstrated a reappearance of the ITD and 3 patients remained negative at relapse. One patient, among 45 patients who relapsed, had a negative baseline ITD but acquired a de novo ITD at relapse. There were 101 samples from 93 patients in remission; they were all negative for an ITD. Among 34 patients who failed to achieve a remission, five patients had a persistent ITD and one patient had a de novo ITD. These results support the concept of resistance of FLT3 ITD leukemic clones to chemotherapy. Therefore, effective therapy with FLT3 targeting agents may improve the prognosis of non-M3 AML patients with the FLT3 mutation.

Background: We intended to evaluate the diagnostic usefulness of a multiplex reverse transcriptase- PCR (mRT-PCR) assay kit under dual priming oligonucleotide system (DPO) for the childhood acute respiratory tract infections., Methods: Two hundred nasopharyngeal aspirates were taken from children < or =5 yr old admitted due to acute respiratory infections in 2004. Direct fluorescent antibody (FA) assays were performed with fresh specimens; then, mRT-PCRs for the detection of 12 respiratory viruses (Seeplex RV detection kit, SeeGene, Seoul, Korea) were tested with frozen specimens., Results: FA assays for five common respiratory viruses showed positive results in 66 patients (33.0%), while mRT-PCR detected causative viruses in 112 patients (56.0%), including 16 co-infected cases (8.0%). A total of 129 viruses were identified: respiratory syncytial virus A/B (38.0%/7.8%), influenza virus A/B (10.1%/5.4%), parainfluenza virus 1/2/3 (7.0%/3.1%/7.8%), coronavirus 229E or NL63 (6.2%), human metapneumovirus (4.7%), adenovirus (4.7%), rhinovirus (3.9%), and coronavirus OC43 (1.6%)., Conclusions: DPO-based mRT-PCR was found as a sensitive tool for the detection of the viruses that cause childhood respiratory infections. Clinical significances of the agents detected by mRTPCR need further evaluations.

Diagnosis of Mycoplasma pneumoniae infection is important due to its variable clinical manifestations and absence of response to beta-lactams. Introduction of enzyme immunoassays (EIAs) for serologic diagnosis of M. pneumoniae has made it possible to separate the analyses of specific IgG and IgM antibodies. We compared four different commercial EIAs, ImmunoWELL IgG, IgM (GenBio), Medac IgG, IgA, IgM (Medac), Platelia IgG, IgM (Sanofi Pasteur), and Ridascreen IgG, IgA, IgM (r-Biopharm) with indirect particle agglutination assay (PA), Serodia-MycoII (Fujirebio). We tested 91 specimens from 73 pediatric patients (2-17 yr) hospitalized at a tertiary-care hospital between December 2005 and January 2006. The measurements of IgM EIAs were correlated with PA titers (Spearman's correlation coefficient, from 0.89 to 0.92) with high concordance rates, ranging from 82.4% to 92.3%. However, some negative IgM-EIA results in PA-positive specimens indicated that serial samplings with convalescent sera would be necessary to confirm M. pneumoniae infection.

Background: We investigated the Janus kinase 2 (JAK2) mutation and its diagnostic value in patients suffering with non BCR/ABL myeloproliferative diseases (nMPD) or other reactive conditions., Methods: We reviewed the clinical records of 83 patients who underwent bone marrow (BM) examinations with suspect of nMPD. The diagnoses of nMPD were made based on the WHO criteria since 2001 and the PVSG criteria before 2001. The JAK2 mutation was examined by PCR in 54 patients whose BM samples were available., Results: The JAK2 mutation was detected in 25 patients (46%); 12 of 26 patients with essential thrombocythemia (ET), 9 of 12 patients with polycyhtemia vera (PV), one of 7 patients with chronic idiopathic myelofibrosis (CIM) and one patient with unclassifiable MPD. Additionally, JAK2 mutation was detected in each one patient with secondary polycythemia and reactive thrombocytosis. These two patients and two other patients among the JAK2 mutated ET did not meet the WHO PV criteria due to their initial low hemoglobin levels. These patients had liver cirrhosis and hypersplenism due to Budd-Chiari syndrome (1), gastrointestinal bleeding (1) or the initial hemoglobin level was slightly below the level as provided by the criteria, but the level showed a rising pattern despite cytoreductive therapy (2). With the results of the JAK2 mutation available, 4 patients' disease could be re-diagnosed as PV. Finally, the positive rate of the JAK2 mutation was 81% in PV, 48% in ET and 14% in CIM. The presence of JAK2 mutation closely correlated with PV (p = 0.001), leukocytosis (0 = 0.001) and an increased cellularity of BM (p=0.024)., Conclusions: The JAK2 mutation may help differentiate nMPD from secondary cytosis. Therefore, it should be incorporated into the guidelines for the nMPD work-up for making a more accurate diagnosis and administering proper treatment.

Background and Objectives: In spite of the high complete remission rate that chemotherapy achieves in acute myeloid leukemia with AML1-ETO gene rearrangement, relapse is a major cause of treatment failure in this condition. We aimed to determine a predictor of relapse with the real-time quantitative reverse transcription polymerase chain reaction (RQ-PCR) of AML1-ETO chimeric mRNA., Design and Methods: We serially monitored AML1-ETO fusion transcripts using RQ-PCR in 113 bone marrow or peripheral blood samples from 21 patients with AML1-ETO-positive acute myeloid leukemia and analyzed the prognostic relevance of the results., Results: Higher transcript levels at diagnosis were associated with a higher probability of relapse (p=0.038 in all patients and p=0.001 in adult patients). A decrease of less than 3-log at the time of achieving complete remission was also associated with a higher risk of relapse (p=0.035 in all patients and p=0.011 in adult patients). RQ-PCR detected the reappearance of AML1-ETO fusion transcripts in both peripheral blood and bone marrow during apparent complete remission. Detection of the transcripts preceded hematologic relapse by one to three months. The transcript levels in peripheral blood correlated with those in bone marrow at the same time point., Interpretation and Conclusions: Our findings indicate that regular monitoring of AML1-ETO chimeric transcript levels by RQ-PCR on bone marrow or peripheral blood samples could be extremely useful for the selection of high-risk patients and be an early predictor of relapse.

Chronic granulomatous disease (CGD) is a fatal genetic disorder in which phagocytes fail to produce antimicrobial superoxide because of NADPH oxidase deficiency. Molecular defects in CYBB gene causing X-linked CGD are responsible for about 70% of all cases. This study was done to confirm genetic defects of CYBB gene in five Korean patients who were highly suggestive of having CGD by clinical history. We performed initial screening for five unrelated Korean patients using single strand conformation polymorphism (SSCP) and then selective sequencing for the regions involving the abnormal bands. Activated NBT tests revealed that all patients were X-linked. SSCP analysis for CYBB gene showed abnormal bands in all patients. The molecular defects of five patients were as follows: c.1663insT, c.1111-1G>T, c.39&#95;40insG, c.927delC and c.434T>C mutation. This result will help the families with prenatal diagnosis or genetic counseling.