Identification of clinical factors related to antibody-mediated immune response to the subfornical organ.

OBJECTIVE: We recently reported cases of adipsic hypernatremia caused by autoantibodies against the subfornical organ in patients with hypothalamic-pituitary lesions. This study aimed to clarify the clinical features of newly identified patients with adipsic hypernatremia whose sera displayed immunoreactivity to the mouse subfornical organ. DESIGN: Observational cohort study of patients diagnosed with adipsic hypernatremia in Japan, United States, and Europe. METHODS: The study included 22 patients with adipsic hypernatremia but without overt structural changes in the hypothalamic-pituitary region and congenital disease. Antibody response to the mouse subfornical organ was determined using immunohistochemistry. The clinical characteristics were compared between the patients with positive and negative antibody responses. RESULTS: Antibody response to the mouse subfornical organ was detected in the sera of 16 patients (72.7%, female/male ratio, 1:1, 12 pediatric and 4 adult patients). The prolactin levels at the time of diagnosis were significantly higher in patients with positive subfornical organ (SFO) immunoreactivity than in those with negative SFO immunoreactivity (58.9 ± 33.5 vs. 22.9 ± 13.9 ng/ml, p < .05). Hypothalamic disorders were found in 37.5% of the patients with positive SFO immunoreactivity. Moreover, six patients were diagnosed with rapid-onset obesity with hypothalamic dysfunction, hypoventilation, and autonomic dysregulation/neural tumor syndrome after the diagnosis of adipsic hypernatremia. Plasma renin activity levels were significantly higher in patients with serum immunoreactivity to the Nax channel. CONCLUSIONS: The patients with serum immunoreactivity to the SFO had higher prolactin levels and hypothalamic disorders compared to those without the immunoreactivity. The clinical characteristics of patients with serum immunoreactivity to the subfornical organ included higher prolactin levels and hypothalamic disorders, which were frequently associated with central hypothyroidism and the presence of retroperitoneal tumors.

New classification and diagnostic criteria for insulin resistance syndrome.

This report of a working group established by the Japan Diabetes Society proposes a new classification and diagnostic criteria for insulin resistance syndrome. Insulin resistance syndrome is defined as a condition characterized by severe attenuation of insulin action due to functional impairment of the insulin receptor or its downstream signaling molecules. This syndrome is classified into two types: genetic insulin resistance syndrome, caused by gene abnormalities, and type B insulin resistance syndrome, caused by autoantibodies to the insulin receptor. Genetic insulin resistance syndrome includes type A insulin resistance as well as Donohue and Rabson-Mendenhall syndromes, all of which are caused by abnormalities of the insulin receptor gene; conditions such as SHORT syndrome caused by abnormalities of PIK3R1, which encodes a regulatory subunit of phosphatidylinositol 3-kinase; conditions caused by abnormalities of AKT2, TBC1D4, or PRKCE; and conditions in which a causative gene has not yet been identified. Type B insulin resistance syndrome is characterized by severe impairment of insulin action due to the presence of insulin receptor autoantibodies. Cases in which hypoglycemia alone is induced by autoantibodies that stimulate insulin receptor were not included in Type B insulin resistance syndrome.

Genetic basis of early-onset, maturity-onset diabetes of the young-like diabetes in Japan and features of patients without mutations in the major MODY genes: Dominance of maternal inheritance.

BACKGROUND: Causative mutations cannot be identified in the majority of Asian patients with suspected maturity-onset diabetes of the young (MODY). OBJECTIVES: To elucidate the genetic basis of Japanese patients with MODY-like diabetes and gain insight into the etiology of patients without mutations in the major MODY genes. SUBJECTS: A total of 263 Japanese patients with early-onset, non-obese, MODY-like diabetes mellitus referred to Osaka City General Hospital for diagnosis. METHODS: Mutational analysis of the four major MODY genes (GCK, HNF1A, HNF4A, HNF1B) by Sanger sequencing. Mutation-positive and mutation-negative patients were further analyzed for clinical features. RESULTS: Mutations were identified in 103 (39.2%) patients; 57 mutations in GCK; 29, HNF1A; 7, HNF4A; and 10, HNF1B. Contrary to conventional diagnostic criteria, 18.4% of mutation-positive patients did not have affected parents and 8.2% were in the overweight range (body mass index [BMI] >85th percentile). HOMA-IR at diagnosis was elevated (>2) in 15 of 66 (22.7%) mutation-positive patients. Compared with mutation-positive patients, mutation-negative patients were significantly older (P = 0.003), and had higher BMI percentile at diagnosis (P = 0.0006). Interestingly, maternal inheritance of diabetes was significantly more common in mutation-negative patients (P = 0.0332) and these patients had significantly higher BMI percentile as compared with mutation-negative patients with paternal inheritance (P = 0.0106). CONCLUSIONS: Contrary to the conventional diagnostic criteria, de novo diabetes, overweight, and insulin-resistance are common in Japanese patients with mutation-positive MODY. A significant fraction of mutation-negative patients had features of early-onset type 2 diabetes common in Japanese, and non-Mendelian inheritance needs to be considered for these patients.

Diagnosis of congenital hyperinsulinism: Biochemical profiles during hypoglycemia.

OBJECTIVES: To define the ranges of biochemical markers during hypoglycemia for the diagnosis of congenital hyperinsulinism (CHI), using high sensitivity insulin assays. SUBJECTS: A total of 298 patients with CHI and 58 control patients with non-hyperinsulinemic hypoglycemia, who were diagnosed after 2007. METHODS: The levels of biochemical markers (glucose, insulin, ß-hydroxybutyrate [BHB], free fatty acids [FFA], lactate, ammonia) at the time of hypoglycemia were analyzed along with the maximal glucose infusion rate (GIR) to maintain euglycemia and clinical outcomes. RESULTS: Median levels of blood glucose in patients with CHI and in controls were 30 and 46 mg/dL, while insulin levels were 9.90 and undetectable (<.5) µU/mL, respectively. Similarly, median levels of BHB were 17.5 and 3745 µmol/L, and those of FFA were 270.5 and 2660 µmol/L, respectively. For patients after 5 months, cutoffs of insulin >1.25 µU/mL, BHB < 2000 µmol/L, and FFA < 1248 µmol/L predicted CHI with sensitivities of 97.5, 96.2, and 95.2% and specificities of 84.2, 89.3, and 92.3%, respectively. Maximal GIR in the CHI groups tended to decrease with age. In addition, decreased gestational age, low birth weight, and elevated lactate at hypoglycemia were significantly more common in patients who were off treatment within 100 days without pancreatectomy. CONCLUSIONS: After introduction of high-sensitive assays, the diagnostic value of insulin was improved, allowing for more efficient cutoffs to be set for diagnosis of CHI. Premature birth, low birth weight and elevated lactate might be helpful in predicting early remission of hypoglycemia.

Heterogeneous nature of diabetes in a family with a gain-of-function mutation in the ATP-binding cassette subfamily C member 8 (ABCC8) gene.

Gain-of-function ATP-binding cassette subfamily C member 8 (ABCC8) mutations are known to cause neonatal diabetes mellitus and maturity-onset diabetes in the young. However, the intrafamilial heterogeneous nature of diabetes caused by the ABCC8 mutation is not fully understood to date. To clarify the intrafamilial heterogeneous nature of monogenetic diabetes, we conducted a case study on a family with ABCC8 mutations. We investigated eight family members, including a neonatal diabetes patient, based on metabolic features and genetic analysis. All coding exons and exon-intron boundaries of the KCNJ11, ABCC8, GCK, HNF1A, and HNF4A genes were amplified from genomic DNA and directly sequenced. Five gene mutation carriers with ABCC8 (c.1819G>A/p.V607M) were identified in this family, and the onset and severity of diabetes progressively worsened across the three generations. Each of the ABCC8 gene mutation carrier family members were diagnosed with diabetes as follows: the grandfather with type 2 diabetes at 35 years of age, the aunt with slowly-progressive insulin-dependent diabetes at 18 years of age, the mother with ketosis-onset insulin-dependent diabetes at 14 years of age, the sister with impaired glucose tolerance at 9 years of age, and the proband with transient neonatal diabetes at birth. The present study shows the heterogeneous nature of diabetes in a family with a gain-of-function mutation in the ABCC8 gene.

Incidence rate and characteristics of symptomatic vitamin D deficiency in children: a nationwide survey in Japan.

There is concern that vitamin D deficiency is prevalent among children in Japan as well as worldwide. We conducted a nationwide epidemiologic survey of symptomatic vitamin D deficiency to observe its incidence rate among Japanese children. A questionnaire inquiring the number of new patients with vitamin D deficiency rickets and/or hypocalcemia for 3 years was sent to 855 randomly selected hospitals with a pediatrics department in Japan. In this survey, we found that 250 children were diagnosed with symptomatic vitamin D deficiency. The estimated number of patients with symptomatic vitamin D deficiency per year was 183 (95% confidence interval (CI): 145-222). The overall annual incidence rate among children under 15 years of age was 1.1 per 100,000 population (95% CI: 0.9-1.4). The second survey has provided detailed information on 89 patients with symptomatic vitamin D deficiency under 5 years of age in hospitals in the current research group. The nationwide and second surveys estimated the overall annual incidence rate of symptomatic vitamin D deficiency in children under 5 years of age to be 3.5 (2.7-4.2) per 100,000 population. The second survey revealed 83% had bowed legs, 88% had exclusive breastfeeding, 49% had a restricted and/or unbalanced diet and 31% had insufficient sun exposure among the 89 patients. This is the first nationwide survey on definitive clinical vitamin D deficiency in children in Japan. Elucidating the frequency and characteristics of symptomatic vitamin D deficiency among children is useful to develop preventative public health strategies.

Congenital hyperinsulinism treated by surgical resection of the hyperplastic lesion which had been preoperatively diagnosed by 18F-DOPA PET examination in Japan: a nationwide survey.

PURPOSE: Congenital hyperinsulinism is a rare disease, and the newly developed 18 fluoro-L-dihydroxyphenylalanine-positron emission tomography (18F-DOPA PET) examination can detect hyperplastic lesions. Our purpose was to report the results of a nationwide survey on surgical treatment of congenital hyperinsulinism in Japan. METHODS: A questionnaire was sent to the 159 accredited and affiliated training institutes certified as pediatric surgical institutes by the Japanese Association of Pediatric Surgeons, asking if they had encountered patients who underwent surgical treatment for congenital hyperinsulinism after 18F-DOPA PET examination from 2000 to 2017. Six institutes answered that they had treated such cases, and the total number of cases was 14. RESULTS: 18F-DOPA PET examination detected the focal lesion in 12 of the 14 cases. 18F-DOPA PET examination could accurately determine the site of the hyperplastic lesion in the pancreas in 11 (91.7%) of the 12 cases. All cases underwent surgical resection of the hyperplastic lesion at under 2 years of age. CONCLUSION: Surgical resection of a focal hyperplastic lesion in the pancreas was a safe and effective treatment if the hyperplastic lesion was a focal lesion. However, it is necessary to check the exact distribution of the lesion by intraoperative pathologic examination of frozen sections.

Growth Hormone Treatment for Achondroplasia.

Achondroplasia (ACH) is the most common form of skeletal dysplasia causing rhizomelic, short-limb short stature. Short- and long-term clinical trials have been conducted with rhGH, with similar results across these studies. At supraphysiological dose of GH, height gain of 1-1.5 SDS on the population curve was observed during the first 1-3 years, which was then followed by a smaller increase in growth rate persisting for 5-6 years. These studies led to the approval of rhGH for ACH in Japan where rhGH has been used for 20 years at 0.05 mg/kg/day. Although the available data are still limited, compared to untreated controls, total gain in adult height has been greater in males than in females, reported at 3.5-8.0 cm and 2.8-4.2 cm, respectively. Serious adverse events have been rare although some were potentially life-threatening and need careful monitoring. These results should serve as a comparator for novel emerging treatments for ACH.

Temple syndrome: comprehensive molecular and clinical findings in 32 Japanese patients.

PurposeTemple syndrome (TS14) is a rare imprinting disorder caused by aberrations at the 14q32.2 imprinted region. Here, we report comprehensive molecular and clinical findings in 32 Japanese patients with TS14.MethodsWe performed molecular studies for TS14 in 356 patients with variable phenotypes, and clinical studies in all TS14 patients, including 13 previously reported.ResultsWe identified 19 new patients with TS14, and the total of 32 patients was made up of 23 patients with maternal uniparental disomy (UPD(14)mat), six patients with epimutations, and three patients with microdeletions. Clinical studies revealed both Prader-Willi syndrome (PWS)-like marked hypotonia and Silver-Russell syndrome (SRS)-like phenotype in 50% of patients, PWS-like hypotonia alone in 20% of patients, SRS-like phenotype alone in 20% of patients, and nonsyndromic growth failure in the remaining 10% of patients in infancy, and gonadotropin-dependent precocious puberty in 76% of patients who were pubescent or older.ConclusionThese results suggest that TS14 is not only a genetically diagnosed entity but also a clinically recognizable disorder. Genetic testing for TS14 should be considered in patients with growth failure plus both PWS-like hypotonia and SRS-like phenotypes in infancy, and/or precocious puberty, as well as a familial history of Kagami-Ogata syndrome due to maternal microdeletion at 14q32.2.

Circulating tricarboxylic acid cycle metabolite levels in citrin-deficient children with metabolic adaptation, with and without sodium pyruvate treatment.

Citrin deficiency causes adult-onset type II citrullinemia (CTLN-2), which later manifests as severe liver steatosis and life-threatening encephalopathy. Long-standing energy deficit of the liver and brain may predispose ones to CTLN-2. Here, we compared the energy-driving tricarboxylic acid (TCA) cycle and fatty acid ß-oxidation cycle between 22 citrin-deficient children (age, 3-13years) with normal liver functions and 37 healthy controls (age, 5-13years). TCA cycle analysis showed that basal plasma citrate and α-ketoglutarate levels were significantly higher in the affected than the control group (p<0.01). Conversely, basal plasma fumarate and malate levels were significantly lower than those for the control (p<0.001). The plasma level of 3-OH-butyrate derived from fatty acid ß-oxidation was significantly higher in the affected group (p<0.01). Ten patients underwent sodium pyruvate therapy. However, this therapy did not correct or attenuate such deviations in both cycles. Sodium pyruvate therapy significantly increased fasting insulin secretion (p<0.01); the fasting sugar level remained unchanged. Our results suggest that citrin-deficient children show considerable deviations of TCA cycle metabolite profiles that are resistant to sodium pyruvate treatment. Thus, long-standing and considerable TCA cycle dysfunction might be a pivotal metabolic background of CTLN-2 development.

Molecular and clinical features of KATP -channel neonatal diabetes mellitus in Japan.

BACKGROUND: There are few reports pertaining to Asian patients with neonatal diabetes mellitus (NDM) caused by activating mutations in the ATP-sensitive potassium channel genes (KATP-NDM). OBJECTIVES: To elucidate the characteristics of Japanese patients with KATP-NDM. METHODS: By the amplification and direct sequencing of all exons and exon-intron boundaries of the KCNJ11 and ABCC8 genes, 25 patients with KATP-NDM were identified from a total of 70 patients with NDM. Clinical data were collected from the medical charts. RESULTS: Sixteen patients had mutations in KCNJ11 and nine in ABCC8. Eight novel mutations were identified; two in KCNJ11 (V64M, R201G) and six in ABCC8 (R216C, G832C, F1176L, A1263V, I196N, T229N). Interestingly, V64M caused DEND (developmental delay, epilepsy, neonatal diabetes) syndrome in our patient, while mutation of the same residue (V64G) had been reported to cause congenital hyperinsulinism. Mutations in ABCC8 were associated with TNDM (4/9) or isolated PNDM (5/9), whereas those in KCNJ11 were associated with more severe phenotypes, including DEND (3/16), iDEND (intermediate DEND, 4/16), or isolated PNDM (6/16). Switching from insulin to glibenclamide monotherapy was successful in 87.5% of the patients. Neurological improvement was observed in two patients, one with DEND (T293N) and one with iDEND (R50P) syndrome. Three others with iDEND mutations (R201C, G53D, and V59M) remained neurologically normal at 5, 1, and 4 years of age, respectively, with early introduction of sulfonylurea. CONCLUSION: Overall, clinical presentation of KATP-NDM in Japanese patients was similar to those of other populations. Early introduction of sulfonylurea appeared beneficial in ameliorating neurological symptoms.

MODY3, renal cysts, and Dandy-Walker variants with a microdeletion spanning the HNF1A gene.

Heterozygous hepatocyte nuclear factor-1-α gene (HNF1A) mutations are the most common cause of maturity-onset diabetes of the young (MODY), but they rarely involve extrahepatic manifestations. Renal cysts and diabetes syndrome can be caused by HNF1B mutations. No association between MODY3 and Dandy-Walker variants (DWV) has been reported. HNF1A mutations might be responsible for renal malformations. In a Japanese girl with glycosuria, developmental delay, mental retardation, renal cysts, and DWV, the HNF1B gene had no mutations. Array comparative genomic hybridization analysis identified a de-novo interstitial 12q24.22-q24.31 deletion of 5.6 Mb encompassing the HNF1A gene, which is compatible with a diagnosis of MODY3. The variety of phenotypes suggests a novel microdeletion syndrome spanning the HNF1A gene. Because HNF1B functions as an HNF1A/HNF1B heterodimer, haploinsufficient HNF1A interacts with a certain HNF1B haplotype. The resulting truncated heterodimer might engender renal cysts. More patients with well-defined deletion within 12q.24.31 must be evaluated to produce a detailed genotype-phenotype correlation and to elucidate this emerging microdeletion syndrome.
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Efficacy and safety of octreotide for the treatment of congenital hyperinsulinism: a prospective, open-label clinical trial and an observational study in Japan using a nationwide registry.

Octreotide, a long-acting somatostatin analog, has been used for treating hypoglycemia caused by congenital hyperinsulinism (CHI). However, octreotide has not been evaluated in clinical trials and has not been approved in any developed country. We aimed to test the efficacy and safety of octreotide for diazoxide-unresponsive CHI through a combination of a single-arm, open-label clinical trial (SCORCH study) and an observational study to collect data on the clinical course of patients treated off-label in Japan (SCORCH registry). In the SCORCH study, 5 patients were stabilized (blood glucose > 45 mg/dL) by hypertonic glucose infusion, and treated by continuous subcutaneous octreotide infusion at a dose of 5-25 µg/kg/day. Continuous blood glucose monitoring was performed between -24 and +48 hours. In 3 patients, a clinically meaningful rise in blood glucose was achieved and therapy was continued. The glucose infusion was gradually decreased and stopped after 5, 11, and 174 days, respectively. In one case, remission of CHI was reached after 606 days and octreotide was discontinued. The SCORCH registry included 19 diazoxide-unresponsive patients treated by subcutaneous octreotide, by continuous infusion or multiple daily injections. Of the 17 patients treated with hypertonic glucose infusion, the infusion rate was reduced after 4 weeks to less than 50% in 11 patients (64.7%) and stopped in 9 (52.9%). During the combined observation period of 695.4 patient-months in both studies, no severe adverse events related to octreotide were observed. In conclusion, subcutaneous octreotide injection was effective and well tolerated in the majority of patients with diazoxide-unresponsive CHI.

Low Frequencies of Autoimmunity-Associated PTPN22 Polymorphisms in MODY Patients, Including Those Transiently Expressing Islet Cell Autoantibodies.

BACKGROUND: The protein tyrosine phosphatase nonreceptor type 22 (PTPN22) gene encodes lymphoid tyrosine phosphatase (LYP), which is expressed primarily in lymphoid tissues. The functional but geographically highly variable PTPN22 single-nucleotide polymorphisms (SNPs), particularly c.1858C>T, contribute to the onset and progression of autoimmunity-associated diseases and facilitate the expression of disease-associated autoantibodies. In Central Europe, 17-25% of patients with monogenic diabetes (maturity-onset diabetes of the young, MODY) transiently express islet cell autoantibodies. METHODS: We addressed the links between the functional and geographically variable PTPN22 SNPs with MODY manifestation and the expression of islet cell autoantibodies in 276 MODY patients who originated from four regions (the Czech Republic, Israel, Japan and Brazil). RESULTS: The frequency of PTPN22 polymorphisms in the MODY patients was similar to those in geographically matched healthy populations, with the exception of c.788G>A, the minor allele frequency of which was significantly elevated in the Czech hepatocyte nuclear factor 1-α (HNF1A) MODY patients [odds ratio (OR) 4.8, 95% confidence interval (CI) 2.2-10.7] and the Brazilian MODY patients (OR 8.4, 95% CI 1.8-39.1). A barely significant increase in the c.788G>A minor allele was also detected in the islet cell autoantibody-positive Czech MODY patients. However, c.788A behaves as a loss-of-function mutant in T cells, and thus protects against autoimmunity. CONCLUSIONS: MODY patients (including islet cell autoantibody-positive cases) do not display any increase in autoimmunity-associated PTPN22 alleles. The absence of autoimmunity-associated PTPN22 alleles was also demonstrated in latent autoimmune diabetes in adults, which suggests that the slow kinetics of the onset of autoantibodies is subject to a regulation that is different from that experienced in type 1 diabetes and other autoimmune disorders.

Relapsing 6q24-related transient neonatal diabetes mellitus successfully treated with a dipeptidyl peptidase-4 inhibitor: a case report.

The most common form of transient neonatal diabetes mellitus (TNDM) is 6q24-related TNDM. Patients are treated with insulin during the neonatal period until spontaneous remission. However, diabetes often recurs in adolescence, and there is no standard therapy for patients with a relapse. A paternal duplication at the 6q24 critical region spanning the pleiomorphic adenoma gene-like 1 PLAGL1 gene was found in a Japanese patient with TNDM relapse. The patient was treated with a dipeptidyl peptidase-4 (DPP4) inhibitor, alogliptin, at a dose of 25 mg per day. Immediately after treatment initiation, his hemoglobin A1c (HbA1c) levels dropped from 7.0-7.5% (52-58 mmol/mol) to 6.0-6.5% (41-47 mmol/mol) and remained stable for over a year. We reported the successful treatment of relapsed 6q24-related TNDM with a DPP4 inhibitor. Although insulin has been the conventional treatment for such patients, treatments targeting the GLP1 pathway can be a useful alternative because these patients retain the ß cell mass and responsiveness through G protein-coupled pathways.

Congenital hyperinsulinism: global and Japanese perspectives.

Over the past 20 years, there has been remarkable progress in the diagnosis and treatment of congenital hyperinsulinism (CHI). These advances have been supported by the understanding of the molecular mechanism and the development of diagnostic modalities to identify the focal form of ATP-sensitive potassium channel CHI. Many patients with diazoxide-unresponsive focal CHI have been cured by partial pancreatectomy without developing postsurgical diabetes mellitus. Important novel findings on the genetic basis of the other forms of CHI have also been obtained, and several novel medical treatments have been explored. However, the management of patients with CHI is still far from ideal. First, state-of-the-art treatment is not widely available worldwide. Second, it appears that the management strategy needs to be adjusted according to the patient's ethnic group. Third, optimal management of patients with the diazoxide-unresponsive, diffuse form of CHI is still insufficient and requires further improvement. In this review, we describe the current landscape of this disorder, discuss the racial disparity of CHI using Japanese patients as an example, and briefly note unanswered questions and unmet needs that should be addressed in the near future.

A case of diffuse congenital hyperinsulinism in which continuous glucose monitoring contributed to the choice of a treatment strategy following a subtotal pancreatectomy.

Patients with diffuse congenital hyperinsulinism (CHI) refractory to drug therapy require subtotal or near-total pancreatectomy. Although almost all patients develop diabetes postoperatively, the clinical course and timing of insulin therapy remain unclear. A 7-yr-old girl presented with recurrent hypoglycemia shortly after birth and a relatively elevated insulin level, which confirmed the diagnosis of CHI. Genetic analysis revealed compound heterozygous ATP-binding cassette, Subfamily C, Member 8 pathogenic variants and diffuse CHI was suspected. Because her condition was refractory to diazoxide and octreotide, she underwent a subtotal pancreatectomy at the age of 4 mo. The drug therapy was discontinued. Although an oral glucose tolerance test at the age of 2 yr showed hyperglycemia after loading, continuous glucose monitoring (CGM) revealed that her daily glucose trends were almost within the 70-180 mg/dL range, and mild hypoglycemia appeared during the daytime. After the age of 6 yr, CGM showed an elevation in glucose trends from midnight to early morning, suggesting that insulin secretion was attenuated and hepatic glucose production was insufficiently suppressed. Insulin therapy was initiated at the age of 7 yr. These results indicate that CGM can be useful for making treatment decisions.

A Male Japanese Patient with Temple Syndrome Complicated by Type 2 Diabetes Mellitus.

We herein present the case of a 21-year-old male Japanese diabetic patient with Temple syndrome, caused by maternal uniparental disomy of chromosome 14. The patient was overweight and had type 2 diabetes, dyslipidemia, metabolic dysfunction-associated steatotic liver disease, and microalbuminuria. He had an increased fat mass in the truncal region and a decreased lean mass throughout the body. This may lead to insulin resistance due to the absence of delta-like homolog 1 (DLK1) and retrotransposon gag-like 1 (RTL1). The patient had experienced social withdrawal at home (hikikomori in Japanese), had poorly controlled type 2 diabetes, and was overweight despite receiving diet therapy and oral hypoglycemic agents.

Characteristics of NO cycle coupling with urea cycle in non-hyperammonemic carriers of ornithine transcarbamylase deficiency.

Urea cycle deficient patients with prominent hyperammonemic often exhibit abnormal production of nitric oxide (NO), which reduces vascular tone, along with amino acid abnormalities. However, information related to the metabolic changes in heterozygotes of ornithine transcarbamylase deficiency (OTCD) lacking overt hyperammonemia is quite limited. We examined vascular mediators and amino acids in non-hyperammonemic heterozygotes. Twenty-four heterozygous OTCD adult females without hyperammonemic bouts, defined as non-hyperammonemic carriers, were enrolled. We measured blood amino acids constituting urea cycle and nitric oxide (NO) cycle. Blood concentrations of nitrate/nitrite (NOx) as stable NO-metabolites, asymmetric dimethylarginine (ADMA) inhibiting NO synthesis, and endothelin-1 (ET-1) raising vascular tone were also determined. NOx concentrations were significantly lower in non-hyperammonemic carriers (p < 0.01). However, ADMA and ET-1 levels in this group were comparable to those in the age-matched control group. Arginine and citrulline levels were also significantly lower in non-hyperammonemic carriers than in controls (p < 0.01). Of the 24 non-hyperammonemic carriers, 10 often developed headaches. Their daily NOx and arginine levels were significantly lower than those in headache-free carriers (p < 0.05). In three carriers receiving oral l-arginine, blood NOx concentrations were significantly higher. In two of those three, the occurrence of headaches was decreased. These results suggest that NO cycle coupling with the urea cycle is altered substantially even in non-hyperammonemic OTCD carriers, predisposing them to headaches.