Liquid culture enhances diagnosis of patients with milder forms of non-tuberculous mycobacterial lung disease

OBJECTIVE

To evaluate the proportion and clinical characteristics of patients with non-tuberculous mycobacteria (NTM) lung disease diagnosed based on positive culture results in liquid medium only.

METHODS

We reviewed the medical records of 978 patients diagnosed with NTM lung disease. All clinical samples were cultured in both solid and liquid media.

RESULTS

Of the 978 patients, 111 (11.3%) were culture-positive in liquid medium only (liquid culture group), and 867 (88.7%) (solid culture group) on solid medium, regardless of the culture results in liquid medium. At the time of diagnosis, the liquid culture group was less likely than the solid culture group to have haemoptysis (11.7% vs. 20.0%, P = 0.04), positive sputum smear for acid-fast bacilli (14.4% vs. 50.2%, P < 0.001) or the fibrocavitary form of NTM lung disease (3.6% vs. 14.6%, P = 0.001). During the median follow-up period of 28.9 months (interquartile range 19.1-41.6), the proportion of patients requiring antibiotic treatment was lower in the liquid culture group than in the solid culture group (44.1% vs. 61.6%, P < 0.001).

CONCLUSIONS

Liquid media culture is helpful in the diagnosis of patients with less severe forms of NTM lung disease.

Effects of warm acupuncture on breast cancer-related chronic lymphedema: a randomized controlled trial

BACKGROUND

Effective treatment for breast cancer-related chronic lymphedema (bcrl) remains a clinical challenge. Acupuncture and moxibustion treatments have been shown to be beneficial and safe for treating bcrl. In the present randomized controlled trial, we compared the effectiveness of combined acupuncture and moxibustion ("warm acupuncture") with that of diosmin in bcrl.

METHODS

Breast cancer patients who met the inclusion and exclusion criteria (n = 30) were randomized to experimental and control groups (15 per group). On alternate days, patients in the experimental group received 30 minutes of acupuncture at 6 acupoints, with 3 of the needles each being topped by a 3-cm moxa stick. The control treatment was diosmin 900 mg 3 times daily. The control and experimental treatments were administered for 30 days. Outcome measures included arm circumferences (index of effectiveness), range of motion [rom (shoulder joint function)], quality of life, clinical safety, and adverse events.

RESULTS

Measured by the index of effectiveness, bcrl improved by 51.46% in the experimental group and by 26.27% in the control group (p < 0.00001). Effects were greatest at 10 cm above the elbow and at the wrist, where the warm needling was provided. Impairments in shoulder joint rom were minimal at baseline in both treatment groups. However, the roms of rear protraction, abduction, intorsion, and extorsion in the experimental group improved significantly; they did not change in the control group. Self-reported quality of life was significantly better with warm acupuncture than with diosmin. No adverse effects were reported during the treatment period, and laboratory examinations for clinical safety fell within the normal ranges.

CONCLUSIONS

Compared with diosmin, warm acupuncture treatment can effectively reduce the degree of bcrl at the specific acupoints treated and can promote quality of life. Warm acupuncture showed good clinical safety, without any adverse effects on blood or the cardiovascular system.

Epstein-Barr virus reactivation in extranodal natural killer/T-cell lymphoma patients: a previously unrecognized serious adverse event in a pilot study with romidepsin

BACKGROUND

Romidepsin, a histone deacetylase (HDAC) inhibitor, has been approved for the treatment of relapsed and refractory peripheral T-cell lymphoma. However, the efficacy and safety of romidepsin has never been studied in patients with relapsed or refractory extranodal natural killer (NK)/T-cell lymphoma (ENKTL).

PATIENTS AND METHODS

We conducted an open-label, prospective pilot study to evaluate the efficacy and feasibility of romidepsin in the treatment of patients with ENKTL. The treatment was intravenous infusion of romidepsin (14 mg/m(2)) for 4 h on days 1, 8, and 15 of a 28-day cycle, and was repeated until disease progression or the occurrence of unacceptable toxicity.

RESULTS

A total of five patients enrolled on to this pilot study. However, three patients developed fever and elevated liver enzyme and bilirubin levels immediately after their first administration of romidepsin. We suspected that these events were associated with Epstein-Barr virus (EBV) reactivation because of the rapidly elevated EBV DNA titers in blood from these patients. An in vitro study with the ENKTL cell line SNK-6 cells also showed that HDAC inhibitors including romidepsin increased the copy number of EBV DNA in a dose-dependent manner. These findings suggested that romidepsin-induced histone acetylation reversed the repressed state of the genes required for EBV reactivation and that romidepsin treatment may have caused EBV reactivation in EBV-infected tumor cells in ENKTL patients. Therefore, we discontinued the enrollment of patients into this pilot study.

CONCLUSIONS

Our study suggests that the use of romidepsin may cause severe EBV reactivation in patients with ENKTL.

Clinical characterization and molecular classification of 12 Korean patients with pseudohypoparathyroidism and pseudopseudohypoparathyroidism

CONTEXT

Pseudohypoparathyroidism (PHP) is defined as resistance toward parathyroid hormones. PHP and pseudopseudohypoparathyroidism (PPHP) are rare disorders resulting from genetic and epigenetic aberrations within or upstream of the GNAS locus. This study investigated the clinical characteristics and performed a molecular analysis of PHP and PPHP.

METHODS

A total of 12 patients with (P)PHP from 11 unrelated families (4 with PHP-Ia, 6 with PHP-Ib, and 2 with PPHP) were characterized using both clinical and molecular methods. Clinical features included the presenting symptoms, Albright hereditary osteodystrophy features, and resistance to hormones. Comprehensive analysis of the GNAS and STX16 loci was undertaken to investigate the molecular defects underlying (P)PHP.

RESULTS

All PHP-Ib patients displayed hypocalcemic symptoms. All PHP-Ia patients showed resistance toward TSH, in addition to PTH. In most patients with PHP, when the diagnosis of PHP was first established, hypocalcemia and hyperphosphatemia were associated with a significant increase in serum PTH levels. One patient with PHP-Ia was diagnosed with growth hormone deficiency and showed a good response to human recombinant growth hormone therapy. 6 patients with PHP-Ia and PPHP showed 5 different mutations in the GNAS gene. 5 patients with PHP-Ib displayed a loss of differentially methylated region (DMR) imprints of the maternal GNAS. One PHP-Ib patient showed a de novo microdeletion in STX16 and a loss of methylation of exon A/B on the maternal allele. No patients revealed paternal disomy among 4 patients with PHP-Ib.

CONCLUSIONS

Identification of the molecular causes of PHP and PPHP explains their distinctive clinical features and enables confirmation of the diagnosis and exact genetic counseling.

Frequency of FMR1 premutation carriers and rate of expansion to full mutation in a retrospective diagnostic FMR1 Korean sample

Detection of female premutation (PM) carriers of fragile X syndrome may be important in that a PM allele from the mother can expand to a full mutation (FM) when transmitted to the fetus. Although the PM carrier frequency might be different in varying populations, there is a little data on the Korean population. Furthermore, the risks of expansion to FM have not been studied in Korean PM carriers. In this retrospective study, we estimated the female PM carrier frequency and the risks of expansion to FM in Korean diagnostic samples collected for FMR1 gene testing. Of 10,241 pre-conceptional or pregnant women, 13 PM [1 in 788; 95% confidence interval (CI), 1/1,250-1/455] and 75 intermediate allele carriers (1 in 137; 95% CI, 1/172-1/110) were identified. In 26 prenatal diagnoses cases, the PM allele was transmitted to the fetus in 13 pregnancies (50%), and five of these expanded to FM. All of the maternal alleles exceeding 70 repeats expanded to FM. In conclusion, the PM frequency in Korean diagnostic samples was lower than that reported in Western populations, while the risk for FM expansion in alleles exceeding 70 repeats might be higher than expected based upon previous reports.

Frequencies of 10 autosomal minor histocompatibility antigens in Korean population and estimated disparities in unrelated hematopoietic stem cell transplantation

Disparity of minor histocompatibility antigens (mHAs) is known to induce graft-versus-tumor and graft-versus-host disease reactions in stem cell transplantation. Not much information is available on genotypic and phenotypic distributions of the currently identified mHAs, especially in Korean population. Therefore, we report genotype and phenotype frequency analyses of 10 autosomal mHAs in 329 unrelated healthy Koreans using the Sequenom MassARRAY matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) system and polymerase chain reaction-sequence specific primers (PCR-SSP). Estimates of the probability of immunogenic mismatches between donor/recipient pairs were made from observed phenotypic frequencies. HA-1 was the most favorable mHA for clinical application with the highest disparity of 7.0%. Similar results were obtained in ACC-1. The Korean population can benefit the most in a setting of matched major histocompatibility complex (MHC)-restricted mHAs-mismatched unrelated hematopoietic stem cell transplantations with the disparity rate of 27.5% with eight hematopoietic mHAs. This is the first comprehensive report on the genotypic and phenotypic frequency distributions of human mHAs in the Korean population. It can contribute to not only donor selection before transplantation but also therapeutic approaches after transplantation. It is expected that mHA-based immunotherapy will lead to a new treatment modality tailored for patients at high risk of relapse following allogeneic hematopoietic cell transplantation.

Pantothenate kinase-associated neurodegeneration in Korea: recurrent R440P mutation in PANK2 and outcome of deep brain stimulation

BACKGROUND AND PURPOSE

The purpose of this study was to evaluate the mutation status of PANK2 among Korean patients with pantothenate kinase-associated neurodegeneration (PKAN) and to document the outcome of pallidal deep brain stimulation (DBS).

METHODS

Direct sequencing and deletion/duplication analysis of PANK2 were conducted in 12 patients (11 unrelated) with PKAN, diagnosed on the basis of extrapyramidal dysfunction and the 'eye-of-the-tiger sign' on brain magnetic resonance imaging (MRI). Pallidal DBS was conducted in four patients, and the outcomes were measured using the Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS).

RESULTS

A PANK2 mutation was identified in both alleles in all patients. The most prevalent mutation was c.1319G>C (p.R440P) in 8/22 mutated alleles (36%). An intragenic deletion ranging from exons 2 to 4 was found in one allele (1/22, 4.5%) using deletion/duplication analysis. The outcome of pallidal DBS was favorable in two patients with atypical PKAN and moderate severity of dystonia. However, two patients with typical PKAN and relatively severe symptoms showed variable responses.

CONCLUSIONS

The c.1319G>C (p.R440P) mutation appears to be a founder genotype among Korean patients with PKAN. Furthermore, this study provides additional data for the recent international effort to evaluate the efficacy of pallidal DBS in the treatment of patients with PKAN.

Identification of 11 novel mutations in 49 Korean patients with mucopolysaccharidosis type II

Mucopolysaccharidosis type II (MPS II) or Hunter syndrome is a rare lysosomal storage disorder caused by a deficiency of iduronate-2-sulfatase (IDS). As MPS II is X-linked, patients are usually males with heterogeneous mutations ranging from point mutations to gross deletions and recombination. In 2003, we reported a mutation analysis of 25 patients with MPS II. In this study, 31 mutations in another 49 Korean patients (45 families) with MPS II are reported: 12 missense, nine deletions, four splicing, two nonsense, two insertions, one deletion/insertion, and IDS-IDS2 recombination mutations. Among these mutations, 11 were novel ones (4 missense mutations: Ser61Pro, Pro97Arg, Pro228Ala, and Pro261Ala; 5 deletions: c.344delA, c.420delG, c.768delT, c.1112delC and c.1402delC; 1 deletion/insertion: c.1222delinsTA; and 1 insertion mutation: c.359_360insATCC). The IDS-IDS2 recombination mutations were most frequently observed; all patients with this mutation had the severe MPS II phenotype. However, most of the patients (5/7) with the G374G splicing mutation had an attenuated phenotype, except for two sibling cases with the severe phenotype. Except for a few recurrent mutations such as the G374G, R443X, L522P, and recombination mutations, each patient had a unique individual mutation. Therefore, careful interpretation of genotype-phenotype correlations is warranted.

Direct application of the PCR restriction analysis method for identifying NTM species in AFB smear-positive respiratory specimens

The early differentiation of Mycobacterium tuberculosis from non-tuberculous mycobacteria (NTM) and the identification of NTM species are crucial for the proper management of patients with smear-positive sputum. We evaluated the usefulness of a polymerase chain reaction restriction analysis (PRA) method based on the rpoB gene for identifying NTM species in a study of 121 smear-positive respiratory specimens with presumed NTM. The PRA method amplified mycobacterial DNA in 72 specimens (60%) and differentiated NTM species correctly in 68 (94%). The PRA method could be a useful and rapid method for identifying NTM species in smear-positive respiratory specimens when urgent clinical decisions are required.

Clinical and genetic analysis of a Korean patient with late-onset X-linked adrenal hypoplasia congenita and hypogonadotropic hypogonadism: identification of a novel mutation in the NR0B1 gene

Adrenal hypoplasia congenita (AHC) is caused by mutations in the NR0B1 gene on chromosome Xp21.3-p21.2. It manifests as X-linked primary adrenal failure in early infancy or childhood and as hypogonadotropic hypogonadism (HHG) at puberty. Although studies of AHC patients and mutations in the NR0B1 gene have been reported throughout the world, there has previously been only one other case report from Korea. We encountered a 23-year old Korean male with delayed-onset AHC/HHG who had been previously diagnosed with adrenal insufficiency of unknown aetiology at age 13 years. Delayed puberty and incomplete HHG were observed. Direct sequencing of the NR0B1 gene revealed the patient to have a novel insertion mutation (c.959_960insT; Leu321ProfsX68). Although AHC is believed to be rare, it should be considered in a differential diagnosis of patients showing late-onset primary adrenal insufficiency.

Mutation analysis of the genes involved in the Ras-mitogen-activated protein kinase (MAPK) pathway in Korean patients with Noonan syndrome

Noonan syndrome (NS) is a congenital abnormality that affects multiple parts of the body. Approximately 50% of cases are caused by mutations in the PTPN11 gene. NS shares many clinical features with a group of developmental disorders including Costello syndrome and cardio-facio-cutaneous (CFC) syndrome. Recently, KRAS and SOS1 were identified as causative genes for NS. Moreover, mutations in several genes associated with the Ras-mitogen-activated protein kinase (MAPK) pathway, including HRAS, BRAF, MEK1, and MEK2 were identified in patients with Costello syndrome and CFC syndrome. Accordingly, this study carried out mutation analysis of nine genes including PTPN11, SOS1, GRB2, KRAS, HRAS, NRAS, BRAF, MEK1, and MEK2 associated with the Ras-MAPK pathway in 14 Korean patients with NS. Seven patients were found to have mutations in the PTPN11 gene. Mutation analyses of the other genes did not reveal any disease causing mutations except for one unclassified variation in the 3'-untranslated region of the HRAS gene (c.*1C>T). The patient's father also had the same substitution with the normal phenotype. Therefore, this variation is believed to be either a rare polymorphism or a disease-related variation with variable penetrance. The Ras-MAPK pathway has now emerged as a key cascade in a group of similar developmental disorders as well as in many types of cancers. This study found that, with the exception of PTPN11, mutations in genes related to the Ras-MAPK pathway appear to be uncommon, at least in Korean patients with NS.

Mitochondrial GTPase mitofusin 2 mutations in Korean patients with Charcot-Marie-Tooth neuropathy type 2

Charcot-Marie-Tooth disease (CMT) is classified into two types, the demyelinating (CMT1) and axonal forms (CMT2). CMT2 is further subdivided by linkage analysis into eight subgroups. Recently, mutations in the MFN2 gene, which encodes the mitochondrial GTPase mitofusin 2 (Mfn2) that regulates the mitochondrial network architecture by fusing the mitochondria, were identified in CMT2A patients. This study carried out mutation analysis of the MFN2 gene in 12 unrelated Korean patients suspected of having CMT2 and identified four mutations (Arg94Trp, His165Arg, Ser263Pro, and Ser350Pro). Three mutations were found within the highly conserved GTPase domain that is essential for the function of Mfn2, and one mutation (Ser350Pro) was observed between the GTPase domain and the downstream coiled-coil domain. This suggests that mutations in the MFN2 gene are an important causative gene underlying Korean patients with CMT2, and screening for a mutation in the MFN2 gene is strongly recommended for making a molecular diagnosis of CMT2.

Molecular characterization of enteroviruses isolated from patients with aseptic meningitis in Korea, 2005

Enteroviruses are the most common causative agents of aseptic meningitis. In 2005, an outbreak of aseptic meningitis occurred in Seoul, Korea, which appeared to be caused by certain enterovirus strains. This study analyzed the clinical isolates from 24 different aseptic meningitis patients at our center from January to September 2005. Serotyping using type-specific antisera, RT-PCR, and direct sequencing of the 5' noncoding and VP1 regions were carried out. The serotyping study identified 15 coxsackievirus B5 (CBV5), 4 coxsackievirus B1 (CBV1), 1 coxsackievirus B3 (CBV3) and 4 echovirus 9 (ECV9). Phylogenic analysis of the VP1 region revealed CBV5 to be the most predominant strain (15 strains). Twelve of these strains were grouped together with recent strains isolated in China and France. The 12 CBV5 strains contained a novel amino acid change in the BC-loop (the 90th and 91st, AY --> GN) compared to the reference strain (1954/UK/85). The amino acid changes in the BC-loop in some recent CBV5 strains tend to be located in the C-terminal part, and these changes suggest some antigenic significance.

A novel locus for X-linked recessive CMT with deafness and optic neuropathy maps to Xq21.32-q24

The authors describe a Korean family with X-linked recessive Charcot-Marie-Tooth disease (CMT) having deafness and optic neuropathy. An X chromosome-wide linkage analysis identified a 15.2-cM candidate region flanked by DXS990 and DXS8067 on Xq21.32-q24 with the maximum lod score at DXS8077 (3.62, theta = 0.00). This locus does not overlap previously identified four loci for X-linked CMT, and the authors propose it as CMTX5.

The genetic and phenotypic basis of blood group A subtypes in Koreans

A serological and genetic study of Korean blood donors with phenotypic group A subtypes was performed. There were 176 donors with phenotypic A subtypes identified. Exons 6 and 7 from 57 representative donors were sequenced. The A(var) allele (784 G > A) was cloned and sequenced, and a family study demonstrating its inheritance and unusual serological characteristics was performed. The A102 allele was the most frequently identified allele in phenotypically A2 (58%, 11/19) and A2B (68%, 17/25) donors. Anti-A1 was rarely present amongst A2 and A2B donors. The family study revealed that the A(var) allele was expressed as phenotype A(weak)B in A(var)/B heterozygote members, but as phenotype O in A(var)/O heterozygotes. The most frequent allele in Korean donors with the A2 phenotype differs from its Caucasian counterpart, as does the frequency of anti-A1. The A(var) allele demonstrates allelic enhancement in A(var)/B heterozygotes.

Mutation spectrum of the glucose-6-phosphatase gene and its implication in molecular diagnosis of Korean patients with glycogen storage disease type Ia

Glycogen storage disease type Ia (GSD Ia; MIM 232200) is an autosomal recessive inherited metabolic disorder resulting from a deficiency of the microsomal glucose-6-phosphatase (G6Pase), the enzyme that catalyzes the terminal step in gluconeogenesis and glycogenolysis. Various mutations in the G6Pase gene (G6PC) have been found in patients with GSD Ia. To elucidate the spectrum of the G6PC gene mutations, 13 unrelated Korean patients with GSD Ia were analyzed. We were able to identify mutant alleles in all patients, including three known mutations (727G > T, G122D, and T255I) and two novel mutations (P178A and Y128X). The frequency of the 727G > T mutation in Korean patients with GSD Ia was 81% (21/26), which was slightly lower than that (86-92%) in Japanese but much higher than that (44.4%) in Taiwan Chinese. Except one, all patients were either homozygous (9/13) or compound heterozygous (3/13) for the 727G > T mutation; the only patient without the 727G > T mutation was a compound heterozygote for the G122D and Y128X mutations. Our findings suggest that a DNA-based test can be used as the initial diagnostic approach in Korean patients clinically suspected to have GSD Ia, thereby avoiding invasive liver biopsy.

A novel Bvar allele (547 G>A) demonstrates differential expression depending on the co-inherited ABO allele

BACKGROUND AND OBJECTIVES

Genetic analysis of group B donors in Korea was performed.

MATERIALS AND METHODS

Exons 6 and 7 were sequenced in 12 phenotypically B3 donors 6 B3, 6 A1B3.

RESULTS

Consensus sequences all B3 and 2/6 A1B3 donors were present. Four A1B3 donors demonstrated a novel B allele, B(var), in the context of A101/ or A102/B(var) genotypes. Family studies based on an A1B3 donor with the B(var) allele and on another unrelated subject with identical genotype and phenotype revealed B(var)/O01 genotypes with full B-antigen expression.

CONCLUSIONS

B(var) allele is subject to differential expression, depending on the co-inherited ABO allele.

Alpha-1 antichymotrypsin and alpha-2 macroglobulin gene polymorphisms are not associated with Korean late-onset Alzheimer's disease

Alzheimer's disease (AD) is a multifactorial disorder with possible involvement of several genetic and environmental factors. For late-onset AD (LOAD), the epsilon4 allele of apolipoprotein E (APOE) has been identified as a major susceptible gene. However, the observation that APOE epsilon4 accounted for approximately one half of the genetic variance of LOAD prompted many researchers to undertake genome surveys to identify other susceptible genes. Recently, several candidate genes such as alpha-1 antichymotrypsin (ACT) and alpha-2 macroglobulin (A2M) were reported to be associated with LOAD. To evaluate the possible association between these genes and LOAD in Korean population, we genotyped ACT A/T and A2M 5-bp deletion (exon 18) polymorphisms in 89 LOAD cases and 50 age-matched healthy controls. The frequencies of ACT A and A2M 5-bp deletion alleles in LOAD and controls were 0.39 vs. 0.37, and 0.05 vs. 0.05, respectively. Although APOE epsilon4 clearly showed higher frequency in LOAD (0.34) than that in controls (0.09), giving an odds ratio of 5.14 (95% confidence interval, 2.31-11.76), neither ACT nor A2M showed statistically significant difference between LOAD and controls regardless of APOE carrier status. Our results do not support previously reported association of ACT and A2M with LOAD, at least in Korean population.

Naturally acquired antibody responses to the C-terminal region of merozoite surface protein 1 of Plasmodium vivax in Korea

We expressed a protein in Saccharomyces cerevisiae in order to evaluate the humoral immune responses to the C-terminal region of the merozoite surface protein 1 of Plasmodium vivax. This protein (Pv200(18)) had a molecular mass of 18 kDa and was reactive with the sera of individuals with patent vivax malaria on immunoblotting analysis. The levels of immunoglobulin M (IgM) and IgG antibodies against Pv200(18) were measured in 421 patients with vivax malaria (patient group), 528 healthy individuals from areas of nonendemicity (control group 1), and 470 healthy individuals from areas of endemicity (control group 2), using the indirect enzyme-linked immunosorbent assay (ELISA) method. To study the longevity of the antibodies, 20 subjects from the patient group were also tested for the antibody levels once a month for 1 year. When the cutoff values for seropositivity were determined as the mean + 3 x standard deviation of the antibody levels in control group 1, both IgG and IgM antibody levels were negative in 98.5% (465 of 472) of control group 2. The IgG and IgM antibodies were positive in 88.1% (371 of 421) and 94.5% (398 of 421) of the patient group, respectively. The IgM antibody became negative 2 to 4 months after the onset of symptoms, whereas the IgG antibody usually remained positive for more than 5 months. In conclusion, indirect ELISA using Pv200(18) expressed in S. cerevisiae may be a useful diagnostic method for vivax malaria.

No association between the genes for butyrylcholinesterase K variant and apolipoprotein E4 in late-onset Alzheimer's disease

Butyrylcholinesterase (BChE) as well as acetylcholinesterase has been suggested to be associated with Alzheimer's disease (AD). Lehmann et al. [1997: Hum Mol Genet 6:1933-1936] recently reported the synergism between the gene for the K variant of BChE (BCHE-K) and the epsilon4 allele of apolipoprotein E (APOE epsilon4) in late-onset confirmed AD with Caucasian subjects. The authors found that the allelic frequency of BCHE-K was 0.17 in 74 subjects with late-onset histopathologically diagnosed AD, which was higher than the frequencies in elderly control subjects (0.09) and in other dementias (0.07-0.10). The association of BCHE-K with late-onset AD was limited to carriers of APOE epsilon4, giving odds ratios of confirmed late-onset AD of 6.9-12.8. In the present study, we report the BCHE-K allelic frequencies in late-onset AD cases and in age-matched controls of the Korean population, which were 0.22 and 0.17, respectively. We could not find any association between BCHE-K and AD regardless of APOE epsilon4 carrier status. However, APOE epsilon4 clearly showed higher frequency in AD (0.33) than in elderly controls (0.09), giving an odds ratio of 5.2 (95% confidence interval, 2.7-10.0). Our results do not support the conclusion that BCHE-K, or a nearby gene on chromosome 3, acts in synergy with APOE epsilon4 as a susceptibility gene for late-onset AD, at least in the Korean population.