Guide for diagnosis and treatment of hyperphenylalaninemia.

IMPORTANCE: Sapropterin hydrochloride, a natural coenzyme (6R-tetrahydrobiopterin) of phenylalanine hydroxylase, was first approved as a treatment for tetrahydrobiopterin deficiency in 1992 in Japan, and was then approved as a treatment for a tetrahydrobiopterin-responsive hyperphenylalaninemia in 2007 and 2008, in the USA and Japan, respectively. Guidelines are required on the proper use of sapropterin hydrochloride for tetrahydrobiopterin-responsive hyperphenylalaninemia. OBSERVATIONS: It is recommended that tetrahydrobiopterin-responsive hyperphenylalaninemia should be diagnosed in all cases of hyperphenylalaninemia, including phenylketonuria, by tetrahydrobiopterin administration tests rather than by phenotype or blood phenylalanine levels. CONCLUSIONS AND RELEVANCE: If tetrahydrobiopterin-responsive hyperphenylalaninemia is diagnosed, all ages can be treated with sapropterin hydrochloride. Although there are reports that sapropterin hydrochloride is effective and safe for the prevention of maternal phenylketonuria, further investigation is required.

Liver cirrhosis treated by living donor liver transplantation in a patient with AGL mutation c.2607-2610delATTC and c.1672dupA.

Glycogen storage disease type III (GSD III) is an inherited disorder characterized by the accumulation of abnormal glycogen in the liver. Hepatic manifestations were considered as improving with age; however, patients live longer and liver cirrhosis is being recognized. We report a patient of GSD IIIa with liver cirrhosis, which was treated successfully by living donor liver transplantation. The patient proved to be a compound heterozygote for a novel small deletion c.2607-2610delATTC and a known duplication c.1672dupA in AGL, a gene coding glycogen debranching enzyme responsible for GSD III. Molecular diagnosis helped clinical decision-making.

Attitude to extended use and long-term storage of newborn screening blood spots in Japan.

BACKGROUND: Residual dried blood spots (DBS) remaining after routine newborn screening (NBS) tests are candidate specimens for extended uses such as quality assurance and the development of new technology. A trial of NBS using tandem mass-spectrometry was launched in 2004 in Japan. The aim of the present study was to analyze the attitudes of the public, patient families, and medical professionals toward the extended use and long-term storage of residual DBS, and to construct a standardized informational brochure. METHODS: A questionnaire was sent to randomly selected members of the public, members of the Japanese Phenylketonuria (PKU) Association, medical staff of a general hospital, staff of a children's hospital, obstetricians and gynecologists, pediatricians and NBS personnel. Associated responses, which were given in a free comment format, were analyzed by text mining. RESULTS: The awareness ratio of NBS was low in the public (26.6%), but despite this, when a brief explanatory note on NBS was provided, 71.7% of them recognized the necessity of NBS. They were less positive than medical professionals and PKU patient families regarding the extended use of DBS for forensic investigation, for the study of health problems, or long-term storage of residual DBS, regardless of whether these factors affected them personally or not. Among the medical professionals, obstetricians and pediatricians exhibited a higher ratio of negative responses toward the extended use and long-term storage of DBS than others. CONCLUSION: The general public is more conservative than PKU patients and their families or medical professionals about the extended use or long-term storage of residual DBS. Presentation to the public, particularly to couples of childbearing age, of appropriate explanatory information on NBS itself, or the extended use or long-term storage of residual DBS, is recommended.

Non-invasive high-risk screening for Fabry disease hemizygotes and heterozygotes.

The most appropriate time for screening for Fabry disease (FD) is school age. For this reason, we developed non-invasive methods for measuring urinary alpha-galactosidase A (alpha-gal A) protein, using enzyme-linked immunosorbent assay (ELISA), and for globotriaosylceramide (GL-3), using tandem mass spectrometry (MS/MS). We measured these two biomarkers in the urine of previously diagnosed FD hemizygotes and heterozygotes, and in controls. All the classic FD hemizygotes were clearly distinguished from controls by either method alone, and combining the two assays produced 96% sensitivity for detecting heterozygotes. To assess the utility of these methods for screening school children and adults at high risk of FD, a pilot study was conducted. To distinguish FD from 432 controls, cut-off values for alpha-gal A protein and GL-3 were set at the 5th and 95th centile values of the controls, respectively. Among the high-risk patients, the measurements exceeded the cut-off values for both biomarkers in male and female subjects and were strong indicators for Fabry hemizygotes and heterozygotes. However, we recommend that if the results of the first measurements exceed the cut-off values for only one of these biomarkers, another urine sample should be requested for re-assay to confirm the result.

Urine glucose screening program at schools in Japan to detect children with diabetes and its outcome-incidence and clinical characteristics of childhood type 2 diabetes in Japan.

A large number of children with type 2 diabetes have been detected by a urine glucose screening program conducted at schools in Japan since 1975. The incidence of type 2 diabetes in children has increased over the last three decades, and the incidence is estimated to be approximately 3.0/100,000/y during 1975-2000. The incidence of type 2 diabetes in junior high school children is three to six times higher than that in primary school children. More than 80% of children with type 2 diabetes are obese, and boys are more likely to be obese than girls. It is speculated that the increase in the incidence of childhood type 2 diabetes over the years may be a consequence of the increase in the frequency of obesity in school children. However, this trend of increasing incidence of childhood obesity has recently become weaker, and perhaps as a consequence, the incidence of type 2 diabetes has also decreased after the year 2000 in some cities of Japan. Improved attention to physical activity and eating habits among young people may be responsible at least in part to the decrease in the incidence of type 2 diabetes noted in recent years in big cities of Japan.

Recent change in the annual incidence of childhood type 2 diabetes in the Tokyo metropolitan area.

This study evaluated recent changes in the annual incidence of childhood type 2 diabetes in the Tokyo metropolitan area. From 1974 to 2004, a total of 236 students were diagnosed as having type 2 diabetes by the urine glucose screening program at school. The overall incidence of type 2 diabetes was 2.55/100,000. Overall, 83.9% of students with diabetes were obese; junior high school students had a significantly higher incidence than primary school students (0.75 vs. 6.27/100,000). The annual incidences over the 5-yr periods from 1974-2004 were 1.73, 3.23, 3.05, 2.90, 2.70 and 1.41/100,000, respectively. The incidences in 1974-1980 and 2001-2004 were significantly lower than those in 1981-1985, 1986-1990 and 1991-1995, because primary school students in 1974-1980 had a significantly lower incidence (0.27/100,000), and junior high school students in 2001-2004 had a somewhat lower incidence (3.66/100,000) than during 1981-2000. In recent years, Japanese children's lifestyle and eating habits have gradually improved, and this may have contributed to the trend toward decrease in the incidence of type 2 diabetes in 2001-2004 in the Tokyo metropolitan area.

[Magnetic resonance imaging of the brain in phenylketonuria].

To investigate the correlation between the abnormalities of magnetic resonance imaging (MRI) of the brain and blood phenylalanine (Phe) levels in phenylketonuria (PKU) and hyperphenylalaninemia (HPA), we reviewed MRIs from 16 patients with early treated PKU and HPA. Their ages ranged from 4-24 years and were found by mass screening and treated from early infancy, and 5 patients with late detected PKU who were aged 24-33 years. The former patients had no remarkable neurological signs or symptoms. One patient of the latter had severe mental retardation and 3 patients had mild to border mental retardation. Axial T1-weighted and T2-weighted spin echo sequences, fluid attenuated inversion recovery MR sequences (FLAIR) through the brain were performed. The scans were graded according to the extent of increased signal intensity of white matter on T2-weighted and FLAIR sequences. To investigate the influence of plasma Phe levels, three approaches were used. Firstly an average of all yearly serial blood Phe concentration was calculated for each patient, then Phe was determined for a period of 6 months and 12 months prior to MRI, and also for their lifetime up to their age at the time this study began. These average blood Phe levels were classified into four categories: group A:Phe level below 5 mg/dl, group B:5-8 mg/dl, group C:9-12 mg/dl, group D:above 12 mg/dl. MRI findings were not significant in group A. Remarkable high signals of white matter were obtained in group C and D, except for one patient in group D whose MRI finding was normal. MRI findings correlated to long-term dietary control stronger than those of 6 months prior to MRI. The clinical significance of MRI abnormalities is still unclear, and further study is required to clarify the relationship of the MRI findings and clinical conditions.

Early onset distal muscular dystrophy with normal dysferlin expression.

A 7-year-old boy, who was noted to be a slow runner at the age of 2 years, had progressive muscle weakness and atrophy, preferentially affecting distal muscles. At 3 years of age, he had scoliosis and difficulty in standing on tip-toe. Serum creatine kinase was 1074IU/l. Muscle CT scan showed low-density areas in the lower legs and upper arms, but predominantly in the gastrocnemius and soleus muscles. Biopsy of the biceps brachii muscle showed moderate dystrophic changes with normal dysferlin expression on immunohistochemical and western blot analyses. Although muscle involvement mimicked that seen in Miyoshi myopathy (MM), the very early onset of the disease and scoliosis were quite unusual for MM. We, therefore, made the diagnosis of early onset dysferlin-positive distal muscular dystrophy, probably a new type of distal muscular dystrophy.

Usefulness of the addition of metformin to insulin in pediatric patients with type 1 diabetes mellitus.

BACKGROUND: The aim of this study was to evaluate the effect of metformin in addition to insulin therapy in adolescents and young adults with type 1 diabetes mellitus. METHODS: Nine patients, two males and seven females, aged 18.1 +/- 3.0 years, with type 1 diabetes mellitus were studied. They were relatively overweight with a body mass index (BMI) of 24.2 +/- 1.8 and had high levels of HbA1c at 9.5 +/- 1.2% despite high doses of insulin of 74.0 +/- 31.2 U/day. Metformin at the dose of 500-750 mg daily was administered to the patients in addition to insulin therapy for 1 year. RESULTS: HbA1c, BMI and insulin dose were compared before 1 year without metformin therapy, at baseline, and at 3, 6 and 12 months during the use of metformin in addition to insulin therapy. HbA1c lowered (8.6 +/- 1.4**, 8.4 +/- 1.3**, 8.4 +/- 1.2*%), BMI was reduced (23.9 +/- 1.7*, 23.8 +/- 1.8, 23.5 +/- 1.8*), and insulin requirement decreased (69.8 +/- 29.7*, 68.7 +/- 29.8**, 67.3 +/- 29.1**U/d) significantly after the start of metformin therapy (*P < 0.05, **P < 0.01 vs at baseline). There were no adverse events, not even lactic acidosis, during the study period. CONCLUSION: Metformin is safe and may represent a useful adjunct to the management of type 1 diabetes mellitus in adolescents and young adults who have poor glycemic control despite a large amount of insulin.

Annual incidence and clinical characteristics of type 2 diabetes in children as detected by urine glucose screening in the Tokyo metropolitan area.

OBJECTIVE: This study investigates the annual incidence and clinical characteristics of type 2 diabetes among school-aged children as detected by urine glucose screening from 1974 to 2002 in the Tokyo metropolitan area. RESEARCH DESIGN AND METHODS: In total, 8,812,356 school children were examined for glucosuria. Morning urine was used for the analysis. When the urine was positive for glucose, an oral glucose tolerance test was carried out to confirm diabetes. RESULTS: In all, 232 students were identified to have type 2 diabetes. The overall annual incidence of type 2 diabetes was 2.63/100,000. The annual incidence after 1981 was significantly higher than that before 1980 (1.73 vs. 2.76/100,000, P < 0.0001). The annual incidence was significantly higher for junior high school students compared with primary school students (0.78 vs. 6.43/100,000, P < 0.0001). The overall male-to-female ratio of students with type 2 diabetes was 1.0:1.19 (P = 0.296), but it was 1.0:1.56 (P = 0.278) for primary school students. Overall, 83.4% of children with diabetes were obese (> or = 20% overweight). However, nonobese girls (<20% overweight) with diabetes accounted for 23.0% of the patients, whereas markedly obese boys (> or = 40% overweight) accounted for 61.5% of the patients. The frequency of a family history of type 2 diabetes in second- and first-degree relatives was 56.5%. CONCLUSIONS: We confirmed that the incidence of young people with type 2 diabetes increased after 1981 in the Tokyo metropolitan area. The increase in the frequency of this disorder seemed to be strongly related to an increasing prevalence of obesity. Age and genetic susceptibility may be associated with the occurrence of type 2 diabetes.

Non-invasive screening method for Fabry disease by measuring globotriaosylceramide in whole urine samples using tandem mass spectrometry.

Fabry disease is an X-linked sphingolipidosis due to a deficiency of alpha-galactosidase A, which leads to the accumulation of globotriaosylceramide (GL-3) in several organs. When recombinant human alpha-galactosidase A is intravenously administered repeatedly before the patient develops permanent tissue damage, there is evidence that the accumulation of GL-3 is decreased in some organs and that the clinical symptoms are alleviated in some patients. However, Fabry disease is rare and many patients are not diagnosed until adulthood after irreversible tissue damage has occurred. Our group has developed a simple and non-invasive screening method for Fabry disease that measures total GL-3 in whole urine samples by tandem mass spectrometry. Using this method, we found that the concentration of GL-3 in whole urine sample from hemizygous patients, including pre-symptomatic young children with classic type Fabry disease, was significantly higher than that in controls. The mean concentration of GL-3 in urine from heterozygotes with symptoms was significantly higher than control concentrations, but GL-3 levels in the urine from 2 out of 8 heterozygotes of classic type Fabry disease were within control levels. An asymptomatic 14-year old hemizygote in the family of a cardiac variant did not have elevated urinary GL-3. Therefore, screening for the classic type and probably renal variant of Fabry disease is possible by measuring urinary GL-3, using our method. The early diagnosis of cardiac variant hemizygotes and some heterozygotes with all types of Fabry disease will not be possible using our method. We propose that this procedure can be used as a reliable, non-invasive, simple method for general and high-risk population screening for hemizygotic patients with the classic type and probably renal variant of Fabry disease.

Markers associated with inborn errors of metabolism of branched-chain amino acids and their relevance to upper levels of intake in healthy people: an implication from clinical and molecular investigations on maple syrup urine disease.

Maple syrup urine disease (MSUD) is caused by a deficiency in the branched-chain alpha-ketoacid dehydrogenase complex. Accumulations of branched-chain amino acids (BCAAs) and branched-chain alpha-ketoacids (BCKAs) in patients with MSUD induce ketoacidosis, neurological disorders, and developmental disturbance. BCAAs and BCKAs influence on the nervous system can be estimated by analyzing these patients. According to clinical investigations on MSUD patients, leucine levels over 400 micromol/L apparently can cause any clinical problem derived from impaired function of the central nervous system. Damage to neuronal cells found in MSUD patients are presumably because of higher concentrations of both blood BCAAs or BCKAs, especially alpha-ketoisocapronic acids. These clinical data from MSUD patients provide a valuable basis on understanding leucine toxicity in the normal subject.

Optimal use of quick-acting insulin analogue in combination with basal insulin and its long-term effect in Japanese children and adolescents with type 1 diabetes.

The aim of the study was to examine the optimal use of quick-acting insulin analogue (Q) switching from regular insulin (R) in combination with basal insulin and its long-term effects in 40 Japanese children and adolescents with type 1 diabetes. Insulin regimens after administration of Q were increased to twice daily injections of basal insulin and modified use of Q or R as bolus insulin depending on the blood glucose profile and lifestyles. The mean dose of total insulin remained unchanged during treatment with using Q, but that of basal insulin increased 12 months after the use of Q (baseline: 25.8 +/- 12.2, after 12 months: 27.1 +/- 12.6 U/day). After switching to Q, the mean HbA1c value decreased in all patients (baseline: 7.6 +/- 1.0, after 12 months: 7.3 +/- 0.8%), which reflected improvement of HbA1c in patients with HbA1c > or = 8% at baseline. These results indicated that insulin regimens after switching from R to Q varied with increases of the number and the dosage of basal insulin. Use of Q seems to be useful to improve hyperglycemia in patients with a poor glucose profile under conventional insulin treatment with using R. The choice of insulin regimens with using Q in consideration of the blood glucose profile as well as lifestyles may lead to better glycemic control.

Mass screening for Wilson's disease by measuring urinary holoceruloplasmin.

We conducted a mass-screening method to detect presymptomatic Wilson's disease in children by measuring urinary holoceruloplasmin. Two cases of Wilson's disease were found by testing urine samples from 48,819 children. The diagnosis was confirmed by clinical laboratory tests and the detection of a mutated ATP 7B gene.