Whole Exome Sequencing in a Korean Child with Joubert Syndrome-related Disorders

Joubert syndrome and Joubert syndrome-related disorders (JSRDs) are rare autosomal recessive or X-linked disorders characterized by cerebellar vermis hypoplasia and a brain stem malformation, which presents as the “molar tooth sign” in magnetic resonance imaging (MRI). JSRDs are a group of clinically heterogeneous conditions that exhibit neurological manifestations and multiple organ involvement. JSRDs are also genetically heterogeneous, and approximately 20 causative genes that account for 45% of JSRDs have been identified. A 7-yr-old boy visited Wonkwang University Sanbon Hospital with the following presentations: no ocular fixation, ataxia, growth retardation, and hypotonia. Physical examination revealed facial dysmorphism, spindle shaped fingers, and height (99 cm) and weight (13 kg) below the third percentile. Ophthalmic examination revealed retinal dystrophy. A diagnosis of JSRDs was made based on clinical and brain MRI findings. We found two heterozygous variants c.2945 G>T; p.Arg982Met (G>T) and c.2216dupA; p.Phe740Valfs*2 (dupA) in AHI1, and a heterozygous c.3973C>T; p.Arg1325Trp (C>T) variant in KIF7 by whole exome sequencing (WES). Genetic analysis on the proband's father revealed that he had both AHI1 variants, but did not have the KIF7 variant, which was inconsistent with autosomal recessive inheritance. Therefore, the G>T variant and C>T variant were presumed to be of “uncertain significance.” Furthermore, one novel dupA variant was interpreted as “pathogenic,” while the second allele was not detected. Caution should be exercised while interpreting the significance of variants detected by WES. In addition, the involvement of genes other than the 20 known ones will require further investigation to elucidate the pathogenesis of JSRDs.

A Family With a Hemoglobin E Variant Including a Thai Immigrant Woman in Korea

No abstract available.

Peripheral Blood Smear Contamination with Helicosporium Fungi Resembling Microfilaria

No abstract available.

Evaluation of ExiPrep16 Automated System for the Extraction of Nucleic Acids from Nasopharyngeal Swabs for the Detection of Respiratory Viruses

BACKGROUND: Automated nucleic acid extraction offers a standardized sample treatment method, low error rate, and avoids sample nucleic acid contamination for use in molecular diagnostics. Here, we evaluated the performance of automated ExiPrep16 system (Bioneer Co.) in comparison with the manual Viral Gene-spin Viral DNA/RNA Extraction kit (VGspin; iNtRON Biotechnology Inc.) for the detection of respiratory viruses from nasopharyngeal flocked swabs. METHODS: To compare the agreement rate and analytical sensitivity between ExiPrep16 and VGspin, previously collected 78 patient samples and 11 pooled samples of each respiratory viruses and their serially diluted samples (until 1/10(8)), were tested by multiplex reverse-transcriptase PCR (Seeplex RV 12 ACE Detection kit; SeeGene Inc.). In addition, we repeatedly analyzed the threshold cycle of the pooled and 1/10(3) dilution of adenovirus (ADV) and influenza virus A (Flu-A) by using real-time PCR to evaluate the precision and crossover of the ExiPrep16 system. RESULTS: The analytical sensitivity of the ExiPrep16 was comparable to that of VGspin, and the highest detectable dilution varied in the range of 1/10 to 1/10(6) depending on the viruses. The total, overall positive and negative percent agreements of ExiPrep16 in comparison with VGspin were 95.7%, 96.2%, and 95.2%, respectively. The mean (CV%) of pooled and 1/10(3) dilution of ADV were, respectively, 19.2 cycle (2.1%) and 31.6 cycle (4.3%) and those for Flu-A were 22.6 cycle (3.1%) and 35.5 cycle (2.6%). No carryover was detected. CONCLUSIONS: Compared to the manual VGspin, ExiPrep16 ensured nucleic acid extraction for efficient detection of respiratory viruses.

A Case of Platelet Satellitism with Platelet Phagocytosis by Neutrophils and Platelet-neutrophil Agglutination

Platelet satellitism is a rare phenomenon in which platelets adhere to the surface of neutrophils; in addition, platelet phagocytosis by neutrophils and monocytes is rare event. Although its clinical significance and pathophysiology are still unclear, platelet-neutrophil agglutination seems to be the end point of a process that is initiated by platelet satellitism and causes pseudothrombocytopenia and pseudoneutropenia. Differentiating pseudothrombocytopenia is essential to avoid unnecessary diagnostic testing and treatments. This report describes an unusual case of a 64 yr old man who presented with left flank pain and pseudothrombocytopenia, which was caused by platelet satellitism with platelet phagocytosis by neutrophils and platelet-neutrophil agglutination. Platelet satellitism occurred in the presence of ethylenediaminetetraacetic acid (EDTA) at room temperature or 4degrees C, but not at 37degrees C; however, platelet-neutrophil agglutination and pseudoleukopenia were observed in EDTA-treated blood only after a 2-hr incubation period at room temperature. Additionally, platelet satellitism could be induced in packed blood cells from a normal individual during a mixing assay with this patient's plasma. To the best of my knowledge, this is the first reported case of platelet satellitism with platelet phagocytosis by neutrophils and platelet-neutrophil agglutination in Korea.

Comparison of Culture, Direct Immunofluorescence Assay, and Multiplex Reverse Transcriptase PCR for Detection of Respiratory Viruses

BACKGROUND: Rapid detection of causative viruses is important for the management of acute respiratory illnesses. To increase the detection rate and decrease the turnaround time (TAT) and cost, we used 24-well plates instead of R-mix shell vials and changes the report time from once on day 3 to twice on days 1 and 5 of culture. The detection rate and TATs of each culture method, direct immunofluorescence assay (DFA), and multiplex reverse transcriptase polymerase chain reaction (mPCR) were compared. METHODS: Among 2,062 nasopharyngeal swabs (NPSs) received from January 2009 to January 2011, 707 NPSs were cultured in R-mix shell vials and 1,355 NPSs were cultured in 24-well plates. We analyzed 538 NPSs simultaneously using DFA, mPCR, and culture and compared the detection rate for 7 viruses (adenovirus, influenza A and B virus; parainfluenza virus 1, 2, and 3; and respiratory syncytial virus [RSV]). RESULTS: The detection rate when using shell vials was 28.4% (201/707) and was 29.4% (399/1,355) on day 1 and 33.3% (452/1,355) on day 5 when using 24-well plates. In addition, of the 53 viruses that were detected on day 5, 34 were adenovirus, 7 were parainfluenza virus, 4 were influenza A virus, 3 were influenza B virus, 4 were RSV, and 1 was a mix of influenza B and parainfluenza virus. The TAT when using shell vials and 24-well plates was 4.8 days and 2.5 days, respectively. The detection rate for the 7 respiratory viruses using culture, DFA, and mPCR was 24.3%, 20.8%, and 38.5%, and the TAT was 3.7 days, 1.0 day, and 1.4 days, respectively. CONCLUSIONS: Using 24-well plates for virus culture is an efficient method for the detection of respiratory viruses.

A Case of Neuroendocrine Carcinoma and Childhood Myelodysplastic Syndrome in Hyper-IgM Syndrome

Congenital immunodeficiency is one or combined immune defect in immunoglobulin, leukocyte, and complement. These patients have increased susceptibility to respiratory infection. Hence, their infection must be taken care of, tried to gene therapy and stem cell transplantation. We present here a case of hyper-IgM syndrome in an 11-year-old male patient who complained of abdominal distension and abdominal pain. Multiple abdominal masses were detected by abdominal computed tomography (CT) and he was diagnosed with neuroendocrine carcinoma by mass biopsy. There was no evidence of metastasis of cancer cells to the bone marrow, but a dysgranulopoietic feature was noted and he was diagnosed with childhood myelodysplastic syndrome. This is the first report that neuroendocrine carcinoma is associated with childhood myelodysplastic syndrome in hyper-IgM syndrome.

Distribution of hepatitis B virus genotypes in Korea / 대한간학회지

BACKGROUND/AIMS: Considering the incidence of prevailing hepatitis B virus (HBV) genotypes in neighboring nations, the predominance of genotype C in Korea is exceptional and needs to be confirmed by nationwide investigation. METHODS: A total of 510 HBsAg (+) or HBeAg (+) serum samples was collected from subjects in several cities and harbors throughout the Korean peninsula for genotype (A-G)-specific multiplex PCR analysis. Another 40 serum samples from chronic HBV carriers from Iksan city were selected for sequencing of the entire HBV genome. Phylogenetic analysis was performed with 22 whole genomic sequences of Korean HBV strains enrolled in GenBank. RESULTS: An amplicon was found in 377 specimens and genotype C occupied 98.1% (370 cases); none of the other genotypes were found. A mixed pattern of genotypes B and C was seen in seven specimens (1.9%), of which five were tested using PCR targeting the X fragment; no genotype B bands were found. With the exception of 1 case, which was subgenotype A2, whole sequences of Korean HBV strains (n=62) belonged to subgenotype C2. CONCLUSIONS: The prevailing HBV genotype in Korea is C2; the other genotypes occur only rarely. Future studies should include confirmation of the detection of genotypes other than C.

Detection of Respiratory Viruses in Children by Multiplex Reverse Transcriptase PCR, Direct Immunofluorescence Assay, and Shell Vial Culture / 대한임상미생물학회지

BACKGROUND: Direct immunofluorescence assay (DFA) and shell vial culture (SVC) have been used to diagnose respiratory viral infections. Recently a multiplex reverse transcriptase PCR (mRT-PCR) for 12 respiratory viruses has been introduced. We evaluated the diagnostic usefulness of these methods. METHODS: Among 275 nasopharyngeal aspirates (NPAs) received from pediatric patients during the 3-month period from May through July, 2007, 122 samples were selected so as to include diverse viruses and varying numbers of DFA-positive cells for mRT-PCR. Also, the results of the 85 NPAs that had been analyzed by both DFA and SVC were reviewed retrospectively. RESULTS: Detection rates for the seven major respiratory viruses, respiratory syncytial virus (RSV), influenza virus A and B, parainfluenza virus 1, 2, and 3, and adenovirus by DFA vs mRT-PCR were 32.0% and 55.7%, and by DFA vs SVC were 32.9% and 40.0%. A number of adenovirus detected by DFA vs mRT-PCR were 12 and 22, and by DFA vs SVC were 6 and 18. A number of RSV detected were 3 and 6, and 13 and 8, respectively. CONCLUSIONS: mRT-PCR detected the respiratory viruses at the highest rate, followed by SVC and DFA in a decreasing order. However, DFA and multiplex PCR were more sensitive than SVC for RSV, while SVC was more sensitive than the other methods for adenovirus.

Corrections: Distribution of hepatitis B virus genotypes in Korea / 대한간학회지

No abstract available.

A Case of 46,XY Pure Gonadal Dysgenesis with Loss of the Sex-Determining Region of Y Chromosome / 대한진단검사의학회지

A 23-yr-old phenotypic female was seen for primary amenorrhea. Her pubic hair was relatively well developed and external genitalia showed normal female appearance, but breast development was retarded. Transvaginal ultrasonographic examination showed a small uterus with indistinct streak gonads, but both ovaries were not detected. Cytogenetic study revealed 46,XY. In FISH and PCR, the sex-determining region of Y chromosome (SRY) was not detected. We report here a case of 46,XY pure gonadal dysgenesis with loss of the SRY.

5-FU Induces Apoptosis of Fas (+), HepG2 Cells Via Activation of Fas-mediated Caspase and Mitochondria Dysfunction / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: In order to investigate the role of Fas on the chemosensitivity of cancer cells in regards to chemotherapeutic agents, the Fas/FasL signaling pathway of apoptosis was explored in human hepatoma cells. MATERIALS AND METHODS: Fas expression of hepatoma cells including Chang, Huh7, HepG2, and Hep3B cells, was determined by RT-PCR and flow cytometry analysis. Cell viability was measured by MTT assay and apoptosis was assessed by DNA fragmentation assay. The catalytic activity of the caspase-family proteases including caspase-3, 6, 8, and 9 proteases, was tested using fluorogenic biosubstrates. The expression of apoptotic mediators including cytochrome c, PARP, and Bcl2 family proteins were measured from cytosolic and mitochondrial compartments. Mitochondrial membrane potential was measured by fluorescence staining with JC-1, rhodamine 123. RESULTS: Fas mRNA was constitutively expressed in Chang and HepG2 as defined as Fas (+) cells, but not in Huh7 and Hep3B cells, defined as Fas (-) cells. Fas (+) cells were markedly sensitive to 5-FU whereas Fas (-) cells were resistant and able to survive. 5-FU increased Fas expression of Fas (+) HepG2 cells and simultaneously resulted in apoptotic death, characterized by the ladder-pattern fragmentation of genomic DNA. Moreover, it increased the catalytic activity of caspase-8 protease, which eventually cleaved the Bid into truncated Bid which translocated into mitochondria only in Fas (+) cells. It also increased the caspase-9 protease activity with Bax expression, cytosolic release of cytochrome c, and mytochondrial dysfunction only in Fas (+) HepG2 cells. Furthermore, 5-FU increased the enzymatic activity of caspase-3 protease with PARP digestion in HepG2 cells. CONCLUSION: 5-FU exerted cytotoxicity against hepatoma cells via activation of Fas-mediated apoptotic signaling including caspase cascades and mytochondrial dysfunction. Our data suggests that Fas may be an important modulator of the chemosensitivity of cancer cells vis- -vis anticancer chemotherapeutic agents.