Coordinated existence of multiple gangliosides is required for cartilage metabolism.

OBJECTIVE: Gangliosides, ubiquitously existing membrane components that modulate transmembrane signaling and mediate cell-to-cell and cell-to-matrix interactions, are key molecules of inflammatory and neurological disorders. However, the functions of gangliosides in the cartilage degradation process remain unclear. We investigated the functional role of gangliosides in cartilage metabolism related to osteoarthritis (OA) pathogenesis. DESIGN: We generated knockout (KO) mice by targeting the ß1, 4-N-acetylgalactosaminyltransferase (GalNAcT) gene, which encodes an enzyme of major gangliosides synthesis, and the GD3 synthase (GD3S) gene, which encodes an enzyme of partial gangliosides synthesis. In vivo OA and in vitro cartilage degradation models were used to evaluate the effect of gangliosides on the cartilage degradation process. RESULTS: The GalNAcT and GD3S KO mice developed and grew normally; nevertheless, OA changes in these mice were enhanced with aging. The GalNAcT KO mice showed significantly enhanced OA progression compared to GD3S mice in vivo. Both GalNAcT and GD3S KO mice showed severe IL-1α-induced cartilage degradation ex vivo. Phosphorylation of MAPKs was enhanced in both GalNAcT and GD3S KOs after IL-1α stimulation. Gangliosides modulated by GalNAcT or GD3S rescued an increase of MMP-13 induced by IL-1α in mice lacking GalNAcT or GD3S after exogenous replenishment in vitro. CONCLUSION: These data show that the deletion of gangliosides in mice enhanced OA development. Moreover, the gangliosides modulated by GalNAcT are important for cartilage metabolism, suggesting that GalNAcT is a potential target molecule for the development of novel OA treatments.

Decreased regional cerebral blood flow in patients with diphenylarsinic acid intoxication.

BACKGROUND AND PURPOSE: Diphenylarsinic acid (DPAA) intoxication caused by drinking contaminated well water was found in Kamisu, Japan. The symptoms indicated cerebellar-brainstem and temporo-occipital involvement. However, it remains unclear how it affects the human brain. To elucidate the effect of DPAA on the human brain, we analyzed cerebral blood flow (CBF) data after the drinking of DPAA-contaminated water was stopped and investigated the correlation between DPAA exposure level and CBF by single-photon emission computed tomography (CBF-SPECT). METHODS: The DPAA-exposed inhabitants (n = 78) were divided into 35 symptomatic and 43 asymptomatic subjects and compared with 38 healthy controls. The DPAA concentration in nails or hair and well water was measured using a high-performance liquid chromatography system and coupled plasma mass spectrometry after adequate extraction treatment. CBF-SPECT data, obtained within 1 year after the drinking of contaminated well water was stopped, were analyzed by statistical parametric mapping. We also examined the relationship between variations in CBF-SPECT signals and variations in DPAA concentrations in the hair or nails of the subjects. RESULTS: Compared with control subjects, CBF in symptomatic DPAA-exposed subjects was significantly lower in the occipital lobe, including the cuneus and inferior occipital gyri. The DPAA concentration in the nails or hair of subjects was inversely and significantly related to their CBF. CONCLUSION: These data suggest that CBF-SPECT may be useful as a clinical marker to infer the effect of accumulated DPAA on the brain.

Autoimmune arthritis deteriorates bone quantity and quality of periarticular bone in a mouse model of rheumatoid arthritis.

This study showed that autoimmune arthritis induces especially severe osteoporosis in the periarticular region adjacent to inflamed joints, suggesting that arthritis increases the fragility fracture risk near inflamed joints, which is frequently observed in patients with RA. INTRODUCTION: Periarticular osteoporosis near inflamed joints is a hallmark of early rheumatoid arthritis (RA). Here we show that rheumatic inflammation deteriorates the bone quality and bone quantity of periarticular bone, thereby decreasing bone strength and toughness in a mouse model of RA. METHODS: Female BALB/c mice and SKG mice, a mutant mouse model of autoimmune arthritis on the BALB/c background, were used. At 12 weeks of age, BALB/c mice underwent either Sham surgery or bilateral ovariectomy (OVX), and SKG mice underwent intraperitoneal injection of mannan to induce arthritis. Eight weeks later, the mice were killed and the femurs and tibias were subjected to micro-computed tomography, Fourier transform infrared (FTIR) spectroscopic imaging, X-ray diffraction, histology, and mechanical testing. RESULTS: SKG mice developed significant trabecular bone loss in both the distal metaphysis of the femur and the lumbar vertebral body, but the extent of the bone loss was more severe in the distal metaphysis. Neither SKG nor OVX mice exhibited changes in the geometry and matrix properties of the diaphysis of the femur, whereas SKG mice, but not OVX mice, did exhibit changes in these properties in the distal metaphysis of the femur. Bone strength and fracture toughness of the distal metaphysis of the tibia adjacent to the inflamed ankle joint were significantly decreased in SKG mice. CONCLUSIONS: Autoimmune arthritis induces periarticular osteoporosis, characterized by deterioration of cortical bone geometry and quality as well as by trabecular bone loss, leading to severe bone fragility in periarticular bone adjacent to inflamed joints.

Efficacy and safety of osteoporosis medications in a rat model of late-stage chronic kidney disease accompanied by secondary hyperparathyroidism and hyperphosphatemia.

This study showed that bisphosphonate was safe and effective for the treatment of bone disorders in stage 4 chronic kidney disease (CKD) rats. Intermittent teriparatide therapy showed an anabolic action on bone even under secondary hyperparathyroidism conditions without having an adverse effect on mineral metabolism in late-stage CKD. INTRODUCTION: Patients with late-stage CKD are at high risk for fragility fractures. However, there are no consensus on the efficacy and safety of osteoporosis medications for patients with late-stage CKD. In the present study, we aimed to examine the efficacy and safety of alendronate (ALN) and teriparatide (TPD) for treating bone disorder in late-stage CKD with pre-existing secondary hyperparathyroidism using a rat model of CKD. METHODS: Male 10-week-old Sprague-Dawley rats were subjected to a 5/6 nephrectomy or sham surgery and randomized into the following four groups: sham, vehicle (saline subcutaneous (sc) daily), ALN (50 µg/kg sc daily), and TPD (40 µg/kg sc daily). Medications commenced at 24 weeks of age and continued for 4 weeks. Micro-computed tomography, histological analysis, infrared spectroscopic imaging, and serum assays were performed. RESULTS: Nephrectomized rats developed hyperphosphatemia, secondary hyperparathyroidism (SHPT), and high creatinine, equivalent to CKD stage 4 in humans. ALN suppressed the bone turnover and increased the degree of mineralization in cortical bone, resulting in an improvement in the mechanical properties. TPD further increased the bone turnover and significantly increased the degree of mineralization, micro-geometry, and bone volume, resulting in a significant improvement in the mechanical properties. Both ALN and TPD had no adverse effect on renal function and mineral metabolism. CONCLUSIONS: BP is safe and effective for the treatment of bone disorders in stage 4 CKD rats. Intermittent TPD therapy showed an anabolic action on bone even under SHPT conditions without having an adverse effect on mineral metabolism in late-stage CKD.

Chondroprotective effects of high-molecular-weight cross-linked hyaluronic acid in a rabbit knee osteoarthritis model.

OBJECTIVES: We hypothesized that high-molecular-weight (MW) cross-linked (CL) hyaluronic acid (HA) improves joint lubrication and has an enhanced chondroprotective effect. We examined the histopathological changes and friction coefficients in osteoarthritic knee joints after injecting high-MW CL HA. DESIGN: A bilateral anterior cruciate ligament transection (ACLT) model in 20 Japanese white rabbits was used. From week 5 after transection, low-MW HA (0.8 × 10(6) Da; HA80) or high-MW CL HA (6 × 10(6) Da; HA600) was injected weekly into 10 right knee for 3 weeks; normal saline (NS) was injected into the 10 left knee. A sham operation was undertaken to exclude spontaneous osteoarthritis (OA) in five knees. Results were evaluated with macroscopy, histopathology (Kikuchi's score), biomechanical testing, and rheological assessment of the joint fluid viscoelasticity. Statistical analysis was performed using one-way analysis of variance with a 95% confidence interval (CI) (P < 0.05). RESULTS: The macroscopic findings showed severely damaged cartilage in 30% of the NS group and 20% of the HA80 and HA600 groups and intact cartilage in 100% of the sham group. The histological scores and friction coefficients of the HA600 group were significantly lower than those of the NS group (P = 0.007 and P = 0.002, respectively). Viscoelasticity measurements of the joint fluid showed no significant differences between the three treatment groups. CONCLUSION: High-MW CL HA exerts potential chondroprotective effects and produces superior friction coefficients. Our results suggest that HA600 delays the progression of OA effectively and improves joint lubrication significantly.

Depletion of gangliosides enhances cartilage degradation in mice.

OBJECTIVE: Glycosphingolipids (GSLs) are ubiquitous membrane components that play a functional role in maintaining chondrocyte homeostasis. We investigated the potential role of gangliosides, one of the major components of GSLs, in osteoarthritis (OA) pathogenesis. DESIGN: Both age-associated and instability-induced OA models were generated using GM3 synthase knockout (GM3S(-/-)) mice. A cartilage degradation model and transiently GM3S-transfected chondrocytes were analyzed to evaluate the function of gangliosides in OA development. The amount of each series of GSLs in chondrocytes after IL-1α stimulation was profiled using mass spectrometry (MS). RESULTS: OA changes in GM3S(-/-) mice were dramatically enhanced with aging compared to those in wild-type (WT) mice. GM3S(-/-) mice showed more severe instability-induced pathologic OA in vivo. Ganglioside deficiency also led to the induction of matrix metalloproteinase (MMP)-13 and ADAMTS-5 secretion and chondrocyte apoptosis in vitro. In contrast, transient GM3S transfection of chondrocytes suppressed MMP-13 and ADAMTS-5 expression after interleukin (IL)-1α stimulation. GSL profiling revealed the presence of abundant gangliosides in chondrocytes after IL-1α stimulation. CONCLUSION: Gangliosides play a critical role in OA pathogenesis by regulating the expression of MMP-13 and ADAMTS-5 and chondrocyte apoptosis. Based on the obtained results, we propose that gangliosides are potential target molecules for the development of novel OA treatments.

Paraneoplastic cerebellar degeneration caused by ovarian clear-cell carcinoma.

Paraneoplastic cerebellar degeneration is a paraneoplastic neurological syndrome caused by the remote effect of certain systemic cancers and is characterized by subacute cerebellar symptoms. A 62-year-old woman suffering from unidentified cerebellar symptoms was admitted to our hospital. Paraneoplastic cerebellar degeneration was suspected and ovarian cancer was detected after the systemic examination for malignancy. The symptoms of vertigo and dysarthria were improved a little after surgical operation and treatments of γ-globulin, steroid pulse and tacrolimus hydrate. The cerebellar symptoms of paraneoplastic cerebellar degeneration are often evident prior to detection of malignancy. It is important to perform systemic examination for malignancy in case of unidentified cerebellar symptoms.

Genetic variation in the gene encoding calpain-10 is associated with type 2 diabetes mellitus.

Type 2 or non-insulin-dependent diabetes mellitus (NIDDM) is the most common form of diabetes worldwide, affecting approximately 4% of the world's adult population. It is multifactorial in origin with both genetic and environmental factors contributing to its development. A genome-wide screen for type 2 diabetes genes carried out in Mexican Americans localized a susceptibility gene, designated NIDDM1, to chromosome 2. Here we describe the positional cloning of a gene located in the NIDDM1 region that shows association with type 2 diabetes in Mexican Americans and a Northern European population from the Botnia region of Finland. This putative diabetes-susceptibility gene encodes a ubiquitously expressed member of the calpain-like cysteine protease family, calpain-10 (CAPN10). This finding suggests a novel pathway that may contribute to the development of type 2 diabetes.

A genome-wide search for human non-insulin-dependent (type 2) diabetes genes reveals a major susceptibility locus on chromosome 2.

Non-insulin-dependent (type 2) diabetes mellitus (NIDDM) is a common disorder of middle-aged individuals characterized by high blood glucose levels which, if untreated, can cause serious medical complications and lead to early death. Genetic factors play an important role in determining susceptibility to this disorder. However, the number of genes involved, their chromosomal location and the magnitude of their effect on NIDDM susceptibility are unknown. We have screened the human genome for susceptibility genes for NIDDM using non-and quasi-parametric linkage analysis methods in a group of Mexican American affected sib pairs. One marker, D2S125, showed significant evidence of linkage to NIDDM and appears to be a major factor affecting the development of diabetes mellitus in Mexican Americans. We propose that this locus be designated NIDDM1.

Surgical resection of primary tumor in the extremities improves survival for metastatic soft-tissue sarcoma patients: a population-based study of the SEER database.

PURPOSE: The objectives of this study were to clarify whether resection of primary tumor in the extremities for patients with metastatic soft-tissue sarcoma (STS) improves survival, and to clarify patient groups for whom primary tumor resection should be considered. METHODS/PATIENTS: Using the surveillance, epidemiology, and end results database, we identified 1453 patients with metastatic STS of the extremities at initial presentation between 1983 and 2016. Of these 1453 patients, 898 patients underwent primary tumor resection (Surgery group), and 555 patients did not (No-surgery group). RESULTS: After adjusting for patient background by propensity score matching, a total of 804 patients were included for analysis. Patients in the Surgery group showed improved survival (cancer-specific survival (CSS) hazard ratio (HR) = 0.59, 95% confidence interval (CI) 0.50-0.71 overall survival rate (OS) HR = 0.60, 95% CI 0.51-0.70). In subclass analysis, patients with high-grade STS, undifferentiated pleomorphic sarcoma, leiomyosarcoma, or synovial sarcoma showed improved survival in the Surgery group (high grade-CSS HR = 0.57, 95% CI 0.45-0.72, OS HR = 0.58, 95% CI 0.48-0.71; undifferentiated pleomorphic sarcoma-CSS HR = 0.60, 95% CI 0.42-0.84, OS HR = 0.61, 95% CI 0.46-0.82; leiomyosarcoma-CSS HR = 0.50, 95% CI 0.33-0.75, OS HR = 0.50, 95% CI 0.35-0.72; synovial sarcoma-CSS HR = 0.46, 95% CI 0.31-0.68, OS HR = 0.43, 95% CI 0.30-0.62). CONCLUSIONS: Our results indicated that primary tumor resection in metastatic STS exerts positive impacts on survival. Further clinical research is needed to confirm these results.

Atelocollagen-associated autologous chondrocyte implantation for the repair of chondral defects of the knee: a prospective multicenter clinical trial in Japan.

BACKGROUND: New tissue-engineering technology was developed to create a cartilage-like tissue in a three-dimensional culture using atelocollagen gel. The minimum 2-year followup outcome of transplanting autologous chondrocytes cultured in atelocollagen gel for the treatment of full-thickness defects of cartilage in knees was reported from the single institution. The present multicenter study was conducted to determine clinical and arthroscopic outcomes in patients who underwent atelocollagen-associated autologous chondrocyte implantation for the repair of chondral defects of the knees. METHODS: At six medical institutes in Japan, we prospectively evaluated the clinical and arthroscopic outcomes of transplanting autologous chondrocytes cultured in atelocollagen gel for the treatment of full-thickness defects of cartilage in 27 patients (27 knees) with cartilage lesions on a femoral condyle or on a patellar facet over 24 months. RESULTS: The Lysholm score significantly increased from 60.0 +/- 13.7 points to 89.8 +/- 9.5 points (P = 0.001). Concerning the ICRS grade for arthroscopic appearance, 6 knees (24%) were assessed as grade I (normal) and 17 knees (68%) as grade II (nearly normal). There were few adverse features, except for detachment of the graft in two cases. CONCLUSIONS: We concluded that transplanting chondrocytes in a newly formed matrix of atelocollagen gel can promote restoration of the articular cartilage of the knee.

Successful long-term management of adenomyosis associated with deep thrombosis by low-dose gonadotropin-releasing hormone agonist therapy.

We report the case of a patient with adenomyosis complicated by deep vein thrombosis in whom low-dose gonadotropin-releasing hormone agonist (GnRHa) therapy was useful as a uterus-conserving therapeutic option. The patient was a 34-year-old nulliparous woman who presented with edema and pain in the left lower leg. The patient had been treated with four cycles of GnRHa therapy for adenomyosis and repeatedly experienced chronic pelvic pain, dysmenorrhea and anemia due to hypermenorrhea. Leg venography confirmed deep vein thrombosis, and thrombolytic therapy was performed to eliminate symptoms. Because the patient strongly wanted to conserve the uterus, low-dose GnRHa therapy was initiated. The patient is currently taking 450 microg/day buserelin acetate nasally (regular dose: 900 microg/day), and estradiol levels have been maintained at 24-50 pg/ml. Anemia, leg numbness and chronic pelvic pain have dissipated, and the patient has not experienced estrogen deficiency symptoms for more than two years.

Chitosan-based hyaluronan hybrid polymer fibre scaffold for ligament and tendon tissue engineering.

To establish medical use of tissue engineering technology for ligament and tendon injuries, a scaffold was developed which has sufficient ability for cell growth, cell differentiation, and mechanical properties. The scaffold made from chitosan and 0.1 per cent hyaluronic acid has adequate biodegradability and biocompatibility. An animal experiment showed that the scaffold has less toxicity and less inflammation induction. Furthermore, in-vivo animal experiments showed that the mechanical properties of the engineered ligament or tendon had the possibility to stabilize the joint. It was shown that newly developed hybrid-polymer fibre scaffold has feasibility for joint tissue engineering.

Increased expression of αv integrin as a regulator of fibrosis in Dupuytren's nodules.

Although Dupuytren's contracture is characterized by increased transforming growth factor-ß1 (TGF-ß1) and fibrosis in the palmar fascia, the relationship between TGF-ß1 and integrins, which are considered to be related to fibrosis, remains unclear. We investigated the involvement of TGF-ß1 and integrins in the pathological palmar fascia of Dupuytren's contracture. Seven patients underwent partial fasciectomy for treatment of this disease. The nodule and cord were isolated from the fascial tissues of the patients. Control fasciae were obtained from seven patients with carpal tunnel syndrome. Immunohistochemical analysis was performed to detect the fibrosis marker α-smooth muscle actin and integrins in the fascial tissues. The expression of TGF-ß1 and integrins was assessed by real-time polymerase chain reaction. The results suggest that nodules may be areas involved in activation of fibrosis in the fascia, associated with increased expression of TGF-ß1 and αv integrin. Thus, αv integrin may contribute to fibrosis in Dupuytren's contracture by activating TGF-ß1. LEVEL OF EVIDENCE: IV.

Short fusion strategy for thoracolumbar and lumbar adolescent idiopathic scoliosis using anterior dual-rod instrumentation.

AIMS: A total of 30 patients with thoracolumbar/lumbar adolescent idiopathic scoliosis (AIS) treated between 1989 and 2000 with anterior correction and fusion surgery using dual-rod instrumentation were reviewed. PATIENTS AND METHODS: Radiographic parameters and clinical outcomes were compared among patients with lowest instrumented vertebra (LIV) at the lower end vertebra (LEV; EV group) (n = 13) and those treated by short fusion (S group), with LIV one level proximal to EV (n = 17 patients). RESULTS: The allocation of the surgical technique was determined by the flexibility of the TL/L curves and/or neutral vertebrae located one level above LEV as determined on preoperative radiographs. If these requirements were met a short fusion was performed. The mean follow-up period was 21.4 years (16 to 27). The mean correction rate at final follow-up was significantly lower in the S group (74 sd 11%) than in the EV group (88 sd 13%) (p = 0.004).Coronal and sagittal balance, thoracic kyphosis, lumbar lordosis, and clinical outcomes evaluated by the Scoliosis Research Society-22 questionnaire scores were equivalent between the two groups. CONCLUSION: Short fusion strategy, which uses LIV one level proximal to LEV can be considered as an alternative to the conventional strategy, which includes LEV in the fusion, when highly flexible TL/L curves are confirmed and/or neutral vertebrae are located one level above LEV in patients with thoracolumbar/lumbar AIS curves. TAKE HOME MESSAGE: Short fusion strategy can be considered as an alternative to the conventional strategy in patients with thoracolumbar/lumbar AIS curves undergoing anterior spinal fusion with dual-rod instrumentation. Cite this article: Bone Joint J 2016;98-B:402-9.

Maintenance of spontaneous lumbar curve correction following thoracic fusion of main thoracic curves in adolescent idiopathic scoliosis.

AIMS: The aims of our study were to provide long-term information on the behaviour of the thoracolumbar/lumbar (TL/L) curve after thoracic anterior correction and fusion (ASF) and to determine the impact of ASF on pulmonary function. PATIENTS AND METHODS: A total of 41 patients (four males, 37 females) with main thoracic (MT) adolescent idiopathic scoliosis (AIS) treated with ASF were included. Mean age at surgery was 15.2 years (11 to 27). Mean follow-up period was 13.5 years (10 to 18). RESULTS: For the TL/L curve, the mean curve flexibility evaluated with supine pre-operative bending radiographs was 78.6% (standard deviation 16.5%), with no significant loss of correction observed. On comparing patients with an increase of the TL/L curve increase (> 4º, n = 9, 22%) to those without, significant differences were observed in the correction rate of the MT curve at the final follow-up (p = 0.011), correction loss of the MT curve (p = 0.003) and the proportion of patients who had semi-rigid instrumentation (p = 0.003). Pre-operative percentage predicted forced vital capacity (%FVC) was 80%, dropping to 72% at final follow-up (p < 0.001). The Scoliosis Research Society questionnaire score was not significantly different between patients with and without a TL/L curve increase (p = 0.606). Spontaneous lumbar curve correction (SLCC) was maintained up to 18 years following selective ASF in most patients and demonstrated significant correlation with maintenance of MT curve correction. CONCLUSION: Maintenance of MT curve correction using rigid instrumentation provided stable SLCC over time. An observed 8% decrease in %FVC indicates that ASF should be reserved for patients with no or only mild pulmonary impairment. Cite this article: Bone Joint J 2016;98-B:997-1002.

Mutations in the hepatocyte nuclear factor-1alpha/MODY3 gene in Japanese subjects with early- and late-onset NIDDM.

Recent studies have shown that mutations in the hepatocyte nuclear factor (HNF)-1alpha gene are the cause of maturity-onset diabetes of the young type 3 (MODY3). We have screened 193 unrelated Japanese subjects with NIDDM for mutations in this gene: 83 with early-onset NIDDM (diagnosis at <30 years of age) and 110 with late-onset NIDDM (diagnosis > or = 30 years of age). All of the members of the latter group also had at least one sibling with NIDDM. The 10 exons, flanking introns, and promoter region were amplified using polymerase chain reaction and were sequenced directly. Mutations were found in 7 of the 83 (8%) unrelated subjects with early-onset NIDDM. The mutations were each different and included four missense mutations (L12H, R131Q, K205Q, and R263C) and three frameshift mutations (P379fsdelCT, T392fsdelA, and L584S585fsinsTC). One of the 110 subjects with late-onset NIDDM was heterozygous for the missense mutation G191D. This subject, who was diagnosed with NIDDM at 64 years of age, also had a brother with NIDDM (age at diagnosis, 54 years) who carried the same mutation, suggesting that this mutation contributed to the development of NIDDM in these two siblings. None of these mutations were present in 50 unrelated subjects with normal glucose tolerance (100 normal chromosomes). Mutations in the HNF-1alpha gene occur in Japanese subjects with NIDDM and appear to be an important cause of early-onset NIDDM in this population. In addition, they are present in about 1% of subjects with late-onset NIDDM.

Organization and partial sequence of the hepatocyte nuclear factor-4 alpha/MODY1 gene and identification of a missense mutation, R127W, in a Japanese family with MODY.

Hepatocyte nuclear factor-4 alpha (HNF-4 alpha) is a member of the nuclear receptor superfamily, a class of ligand-activated transcription factors. A nonsense mutation in the gene encoding this transcription factor was recently found in a white family with one form of maturity-onset diabetes of the young, MODY1. Here, we report the exon-intron organization and partial sequence of the human HNF-4 alpha gene. In addition, we have screened the 12 exons, flanking introns and minimal promoter region for mutations in a group of 57 unrelated Japanese subjects with early-onset NIDDM/MODY of unknown cause. Eight nucleotide substitutions were noted, of which one resulted in the mutation of a conserved arginine residue, Arg127 (CGG)-->Trp (TGG) (designated R127W), located in the T-box, a region of the protein that may play a role in HNF-4 alpha dimerization and DNA binding. This mutation was not found in 214 unrelated nondiabetic subjects (53 Japanese, 53 Chinese, 51 white, and 57 African-American). The R127W mutation was only present in three of five diabetic members in this family, indicating that it is not the only cause of diabetes in this family. The remaining seven nucleotide substitutions were located in the proximal promoter region and introns. They are not predicted to affect the transcription of the gene or mRNA processing and represent polymorphisms and rare variants. The results suggest that mutations in the HNF-4 alpha gene may cause early-onset NIDDM/MODY in Japanese but they are less common than mutations in the HNF-1 alpha/MODY3 gene. The information on the sequence of the HNF-4 alpha gene and its promoter region will facilitate the search for mutations in other populations and studies of the role of this gene in determining normal pancreatic beta-cell function.