Issues, challenges, and future perspectives of genetic counseling in Republic of Korea: Perspectives of laboratory physicians based on a 2022 survey.

The field of genetic counseling (GC) in the Republic of Korea has evolved from a single medical doctor's clinic to a multidisciplinary service with medical geneticists and non-medical professionals working as a team. Here, we assessed the current status of GC in the Republic of Korea based on professional surveys from the perspective of laboratory physicians. An electronic survey was designed and conducted, with the respondents being 50 certified laboratory physicians who were members of the Korean Society for Genetic Diagnostics. Among the 50 respondents, 12 (24%) operated GC clinics. The number of sessions and cases of GC have been on the rise over the last few years, and counseling for cancer genetics was the most common request. Most respondents considered a good understanding of the genetic test and the ability to interpret the test results as strengths of laboratory physicians as medical geneticists, while the lack of clinical experience was a weakness. Education programs regarding laboratory physicians' needs should be provided for high-quality counseling. Lastly, improving the efficiency of GC by strengthening the workforce through a multidisciplinary team is necessary.

Development and validation of a nomogram to predict pulmonary function and the presence of chronic obstructive pulmonary disease in a Korean population.

BACKGROUND: Early suspicion followed by assessing lung function with spirometry could decrease the underdiagnosis of chronic obstructive pulmonary disease (COPD) in primary care. We aimed to develop a nomogram to predict the FEV1/FVC ratio and the presence of COPD. METHODS: We retrospectively reviewed the data of 4241 adult patients who underwent spirometry between 2013 and 2019. By linear regression analysis, variables associated with FEV1/FVC were identified in the training cohort (n = 2969). Using the variables as predictors, a nomogram was created to predict the FEV1/FVC ratio and validated in the test cohort (n = 1272). RESULTS: Older age (ß coefficient [95% CI], - 0.153 [- 0.183, - 0.122]), male sex (- 1.904 [- 2.749, - 1.056]), current or past smoking history (- 3.324 [- 4.200, - 2.453]), and the presence of dyspnea (- 2.453 [- 3.612, - 1.291]) or overweight (0.894 [0.191, 1.598]) were significantly associated with the FEV1/FVC ratio. In the final testing, the developed nomogram showed a mean absolute error of 8.2% between the predicted and actual FEV1/FVC ratios. The overall performance was best when FEV1/FVC < 70% was used as a diagnostic criterion for COPD; the sensitivity, specificity, and balanced accuracy were 82.3%, 68.6%, and 75.5%, respectively. CONCLUSION: The developed nomogram could be used to identify potential patients at risk of COPD who may need further evaluation, especially in the primary care setting where spirometry is not available.

Hemoglobin Concentration Reference Interval Revisited: a Nationwide Study from Korea.

BACKGROUND: Anemia is a common cause among the elderly for increased mortality. Hemoglobin concentration can be affected by many factors, but the reference interval defined by the World Health Organization has not been adjusted for the previous half century. METHODS: Through using the dataset generated by the National Health Insurance (NHI) health screening program of Republic of Korea, here we attempt to present a close to actual hemoglobin concentration of the Korean population. Between January 2009 and December 2013, a total of 57,409,872 health screening events were registered in the NHI database. Following the exclusion criteria, 6,759,566 participants were enrolled for analyses. RESULTS: Significant portion of the study population was considered 'anemic', while the mean value (2.5% ~ 97.5%) of hemoglobin concentration from the study was 14.8 (12.5 ~ 16.8) g/dL in men and 12.8 (10.6 ~ 14.7) g/ dL in women. Concordant results of hemoglobin concentration declining with age were observed as previous studies have described, supporting the need for separate, possibly lower cutoff in the elderly. CONCLUSIONS: A considerable portion of the participants being categorized as anemia contests the accuracy of the current lower cutoff for anemia. From a large representative dataset, the need for adjustment to the lower cutoff for anemia is suggested.

Clinical Implications of Quantitative JAK2 V617F Analysis using Droplet Digital PCR in Myeloproliferative Neoplasms.

BACKGROUND: JAK2 V617F is the most common mutation in myeloproliferative neoplasms (MPNs) and is a major diagnostic criterion. Mutation quantification is useful for classifying patients with MPN into subgroups and for prognostic prediction. Droplet digital PCR (ddPCR) can provide accurate and reproducible quantitative analysis of DNA. This study was designed to verify the correlation of ddPCR with pyrosequencing results in the diagnosis of MPN and to investigate clinical implications of the mutational burden. METHODS: Peripheral blood or bone marrow samples were obtained from 56 patients newly diagnosed with MPN or previously diagnosed with MPN but not yet indicated for JAK2 inhibitor treatment between 2012 and 2016. The JAK2 V617F mutation was detected by pyrosequencing as a diagnostic work-up. The same samples were used for ddPCR to determine the correlation between assays and establish a detection sensitivity cut-off. Clinical and hematologic aspects were reviewed. RESULTS: Forty-two (75%) and 46 (82.1%) patients were positive for JAK2 V617F by pyrosequencing and ddPCR, respectively. The mean mutated allele frequency at diagnosis was 37.5±30.1% and was 40.7±31.2% with ddPCR, representing a strong correlation (r=0.9712, P<0.001). Follow-up samples were available for 12 patients, including eight that were JAK2 V617F-positive. Of these, mutational burden reduction after treatment was observed in six patients (75%), consistent with trends of hematologic improvement. CONCLUSIONS: Quantitative analysis of the JAK2 V617F mutation using ddPCR was highly correlated with pyrosequencing data and may reflect the clinical response to treatment.

Clinical and Molecular Delineation of a Novel Cys1050Phe Missense Mutation in the ABCC9 Gene in a Korean Patient with Cantú Syndrome.

Cantú syndrome is characterized by congenital hypertrichosis, cardiomegaly, and osteochondrodysplasia and is recognized as a rare syndrome. Although it has previously been reported that the majority of affected individuals have a relatively good prognosis, there are no reports on long-term follow up. Here we report the first case of Cantú syndrome in Korea and the associated changes in overall development with rehabilitation over several months.

Fecal Occult Blood Test Results of the National Colorectal Cancer Screening Program in South Korea (2006-2013).

There has been controversy regarding the clinical utility of fecal occult blood test (FOBT) as a screening tool for colorectal cancer (CRC) in the general population. The purpose of this study was to examine the results of Korea national CRC screening using FOBT from 2006 to 2013 and to evaluate the implementation of the program. We analyzed the results of FOBT, colonoscopy, and the side effects during colonoscopy for the subjects (n = 20,609,909) from the Korea National Health Insurance Cancer Screening database. For evaluation of Korea national CRC screening program implementation over the 8-year period, we calculated uptake rate, FOBT positivity rate, and subsequent test compliance rate. The overall uptake rate was 30.1%, with an increasing pattern from 2006 to 2011. A relatively higher FOBT positivity rate (6.4%) and lower subsequent test compliance rate (46.6%) were observed in comparison to the results previously reported in Western countries. Side effects reported within 3 months period after colonoscopy accounted for 0.17% of all procedures, with bleeding being the most prevalent type. Although the implementation of CRC screening program using FOBT in Korea seems successful, trends in key indicators for Korea national CRC screening program should be monitored continuously.

Real world epidemiology of myeloproliferative neoplasms: a population based study in Korea 2004-2013.

Myeloproliferative neoplasms (MPNs), with an expected increment in number, impose substantial economic and social burdens. To this end, we conducted a nationwide population-based descriptive epidemiology study. We also investigated medical cost associated with MPNs. Prevalence was the highest for essential thrombocythemia (ET) (range 4.1-9.0 per 100,000), followed by polycythemia vera (PV) (range 2.8-5.4 per 100,000) and primary myelofibrosis (PMF) (range 0.5-0.9 per 100,000). ET incurred the highest cumulative total cost at US$35 million and the most frequent hospital visits, while PMF incurred the highest average cost per person at US$5000. The mean hemoglobin level was 16.9 ± 2.2 g/dL for PV males and 15.5 ± 2.7 g/dL for PV females. Further analyses on hemoglobin levels showed the true positive rate of PV from the significantly elevated hemoglobin group (defined as >18.5 g/dL for men and >16.5 g/dL for women) was 3.01% and that of MPNs was 3.1%. Here, we provide the biggest population-based report on MPN epidemiology that can readily be used as a representative Asian data.

Novel in-frame deletion mutation in FLCN gene in a Korean family with recurrent primary spontaneous pneumothorax.

Birt-Hogg-Dubé syndrome (BHDS) is an autosomal dominant disease presenting with skin fibrofolliculomas, pulmonary cysts, primary spontaneous pneumothorax (PSP), and renal cancer. It is caused by germline mutations in the FLCN gene, which encodes folliculin. Here we report a novel in-frame deletion mutation p.F143del (c.427_429delTTC) in exon 6 of FLCN gene in the proband and her two sisters. The proband was a 40-year-old Korean woman who presented with right-sided pneumothorax and papular lesions on the face and neck area but without renal cancer. Her father also had a history of PSP and died of renal cancer at the age of 75. Her older sisters have been treated for recurrent PSP but did not have skin lesions suspicious of fibrofolliculoma. The relative expression of FLCN was significantly reduced in the proband and one of the sibling who was confirmed to have FLCN mutation. In-frame deletions in the FLCN gene have rarely been reported but have been shown to impose significant effect on protein stability of FLCN. Identification of a novel genotype in BHDS will provide clues to the phenotype-genotype relations and may aid in explaining the molecular pathogenesis of diseases related to FLCN mutation.

Analysis of fluorescence in situ hybridization, mtDNA quantification, and mtDNA sequence for the detection of early bladder cancer.

We designed this study to test the sensitivities of cytology, the nuclear matrix protein 22 (NMP22) assay, and fluorescence in situ hybridization (FISH) in the early detection of urothelial carcinoma, and to identify mtDNA alterations in urinary epithelial cells. We collected 41 urine samples and 26 corresponding peripheral blood samples from patients with clinically suspected urothelial carcinoma. The FISH and NMP22 assays detected 92.1% of the cancers, and cytology detected 60.5%. In the low-grade group, NMP22 and FISH analyses were more sensitive than cytology, but in the high-grade group, all three methods showed approximately 90% sensitivity. Overall, the FISH and NMP22, or FISH and cytology assays combined detected 97.4% of cancers, while cytology with NMP22 detected 92.1%. In the low-grade group, the sensitivity of the three methods combined was above 80%, but in high-grade group, the combined sensitivity was approximately 100%. In the mtDNA control region, we detected characteristic heteroplasmic mtDNA substitution mutations in 1 patient and a mtDNA length heteroplasmic mutation in 303 polyC or 16184 poly C in 20 patients. Overall, urothelial carcinoma-specific mtDNA mutations were observed in 20 of the 26 patients (76.9%). The average mtDNA copy numbers in urine samples and corresponding peripheral blood samples (83.45 +/- 60.36 and 39.0 +/- 24.38, respectively) (mean +/- standard deviation [SD]) differed significantly (P < 0.001). The mtDNA copy numbers in the urine samples from patients with high-grade and low-grade tumors (81.83 +/- 67.78 and 86.49 +/- 46.69, respectively) did not differ significantly (P = 0.589). In conclusion, the FISH assay showed the highest sensitivity for detecting low-grade urothelial carcinoma, and mtDNA copy numbers in urine samples were higher than those in the corresponding peripheral blood samples. The frequency of mtDNA mutations in the D-loop region in patients with cancer was approximately 80% in our study. This report further supports the significance of genetic alteration in urothelial carcinoma and the clinical utility of the FISH, mtDNA quantitation polymerase chain reaction, mtDNA sequencing, and capillary electrophoresis for this purpose.

Oxidative status in iron-deficiency anemia.

Oxidative stress is an imbalance between free radicals and antioxidant molecules that can play an important role in the pathogenesis of iron-deficiency anemia (IDA). The aim of this study was to investigate oxidative status in patients with IDA and alteration of oxidative status after iron treatment. Thirty-three female patients with IDA and 25 healthy controls were included in this study. Oxidant and total antioxidant capacity were determined using free oxygen radicals test and free oxygen radicals defence (Form CR 3000, Callegari, Parma, Italy). Catalase activity was measured by spectrophotometer using a commercially available kit (Bioxytech Catalase-520, OxisResearch, Portland, OR). Oxidant activity in patients with IDA was significantly higher than controls (P<0.05), while total antioxidant and catalase activity were significantly lower (P<0.05). After treatment, oxidant, antioxidant, and catalase activity reached the levels of the control group, and no significant differences were observed among groups (P>0.05). In conclusion, our data indicate that blood reactive oxygen species was lower and total antioxidant and catalase activity were higher after rather than before treatment in patients with IDA. The results of our study support the higher oxidative stress hypothesis in IDA; however, due to the limited number of cases included, more studies may be required to confirm the results.

Chronic myelomonocytic leukemia with der(9)t(1;9)(q11;q34) as a sole abnormality.

The chromosomal abnormality der(9)t(1;9)(q11;q34) is a rare occurrence in patients with hematologic malignancies. As far as we know, only 3 cases of acute myeloid leukemia, 1 case of polycythemia vera, and 1 case of multiple myeloma with this derivative chromosome have been reported in the literature. Here we report the first case of der(9)t(1;9)(q11;q34) in a patient with chronic myelomonocytic leukemia (CMML). A 45-yr-old man was brought to our hospital for evaluation of pancytopenia and monocytosis. The patient's persistent monocytosis in peripheral blood and his bone marrow findings were consistent with the diagnosis of CMML. Chromosome study results repeatedly showed 46,XY,der(9)t(1;9)(q11;q34). In addition, the BCR/ABL fluorescent in situ hybridization (FISH) pattern of the interphase cells was interpreted as: "nuc ish(ABL, BCR) x 2[292/300]," consistent with the normal signal patterns found in 97% of the nuclei examined. For further evaluation, multi-color FISH (mFISH) analysis was performed and it showed the distinct unbalanced derivative chromosome der(9)t(1;9)(q11;q34) in 5 metaphase cells analyzed. Not only does this show an extraordinary type of trisomy 1q, but it reveals a rare recurrent case of der(9)t(1;9)(q11;q34) in patients with monocytic-lineage leukemia. Further studies are needed to evaluate the prognosis, survival, and treatment response of such patients with der(9)t(1;9)(q11;q34).

JAK2 V617F/C618R mutation in a patient with polycythemia vera: a case study and review of the literature.

The acquired Janus kinase 2 (JAK2) V617F mutation shows a high frequency in diverse BCR/ABL-negative chronic myeloproliferative disorders (CMPD), and it is typically associated with polycythemia vera (PV). The frequency of JAK2 V617F mutation is about 90% in patients with PV, 50-60% in patients with essential thrombocythemia (ET), primary myelofibrosis (PMF), and less in patients with other myeloid neoplasms, while extremely rare in lymphoid malignancies. About 20 kinds of novel mutations of JAK2 other than V617F have been reported recently in the literature. Among these mutations, only one case of JAK2 V617F/C618R has been reported in a 67-year-old patient with PV. Here, we report a rare case of JAK2 V617F/C618R in a 41-year-old Korean male patient with review of the relevant literature on JAK2 mutations other than V617F. Although the frequency of JAK2 mutations other than the V617F is very low, this study emphasizes the need for assiduous analysis of the JAK2 gene to characterize new mutations, to determine their frequency, and to improve understanding of the clinical phenotypes as well as prognostic and biologic features associated with these mutations.

A novel de novo mutation in the serine-threonine kinase STK11 gene in a Korean patient with Peutz-Jeghers syndrome.

BACKGROUND: Peutz-Jeghers syndrome (PJS) is an unusual autosomal dominant disorder characterized by mucocutaneous pigmentation and multiple gastrointestinal hamartomatous polyps. Patients with PJS are at an increased risk of developing multi-organ cancer, most frequently those involving the gastrointestinal tract. Germline mutation of the STK11 gene, which encodes a serine-threonine kinase, is responsible for PJS. METHODS: Using DNA samples obtained from the patient and his family members, we sequenced nine exons and flanking intron regions of the STK11 gene using polymerase chain reaction (PCR) and direct sequencing. RESULTS: Sequencing of the STK11 gene in the proband of the family revealed a novel 1-base pair deletion of guanine (G) in exon 6 (c.826delG; Gly276AlafsX11). This mutation resulted in a premature termination at codon 286, predicting a partial loss of the kinase domain and complete loss of the C-terminal domain. We did not observe this mutation in both parents of the PJS patient. Therefore, it is considered a novel de novo mutation. CONCLUSION: The results presented herein enlarge the spectrum of mutations of the STK11 gene by identifying a novel de novo mutation in a PJS patient and further support the hypothesis that STK11 mutations are disease-causing mutations for PJS with or without a positive family history.