Neonatal Mass-Screening for Inborn Errors of Metabolism in Japan

This report describes the results of neonatal mass screening in Japan for PKU, maple syrup urine disease, histidinemia, homocystinuria, galactosemia, inborn errors of urea cycle metabolism and congenital hypothyroidism. The incidence of PKU is low but the incidence of histidinemia is somewhat high compared to that in the United States. Some genetic variants of each of these inborn errors of metabolism such as malignant hyperphenylalaninemia or mild form of MSUD have been detected in the neonatal screening. Clinical values of the screening for each of these in born errors of metabolism are discussed.     

Follow-up study of a nation-wide neonatal metabolic screening program in Japan

A nationwide neonatal sreening program for phenylketonuria (PKU), maple syrup urine disease (MSUD), homocystinuria, histidinemia and galactosemia was started in Japan in 1977. The total number of infants screened had reached 6,311,754 by March, 1982. A follow-up study revealed the incidence of the disease in Japan: 1/108,823 for PKU; 1/450,840 for hyperphenylalaninemia (HPA); 1/1,577,939 for biopterin deficiency; 1/525,980 for MSUD; 1/1,051,959 for homocystinuria; 1/8,371 for histidinemia, and 1/788,969 for galactosemia type 1. The incidences of PKU, HPA, homocystinuria, and galactosemia (type 1) were found to be markedly low in Japan as compared with those in Caucasian countries. There was no great difference in the incidence of MSUD between both. On the other hand, the incidence of histidinemia was higher in Japan.It was found that most of the patients with PKU, HPA, MSUD, homocystinuria, or galactosemia are developing normally due to the early initiation of dietary treatment. These results clearly indicate that the neonatal mass screening program plays a great role in preventing the occurrence of handicapped children.     

Correlation between Hypoglycemia and Positive Rate of Inborn Error of Metabolism in Neonatal Intensive Care Unit

Objective

To investigate the correlation between hypoglycemia and positive rate of inborn error of metabolism (IEM) in neonatal intensive care unit.

Methods

160 patients from a neonatal intensive care unit were enrolled. Blood glucose was measured by Roche Modular chemistry. The dry blood on filter papers, collected from 160 patients, was tested by tandem mass spectrometry to detect 35 inborn errors of metabolism. Clinical follow-up of all the patients was at least in an interval of 12 months. The mean observation period was 13.5 months per child.

Findings

Based on the ROC curve, the optimal cut-off value of hypoglycemia as an indicator for screening for IEMs was projected to be 2.8 mmol/L, which yielded a sensitivity of 71.4% and a specificity of 76.5%. The patients were divided into two groups: hypoglycemia group (48 cases) and the control group (112 cases). 5(10.4%) of the 48 patients in the hypoglycemia group were positive, while only 2(1.8%) of the 112 patients in the control group were positive. The difference of the positive rate in the screening for IEMs between the two groups was significant (χ²=4.10, P<0.05); the relative risk (RR) was 5.83 (95% CI: 1.06–32.12).

Conclusion

The risk of patients with hypoglycemia suffering from IEMs was significantly higher than that of the non-hypoglycemia patients in NICU, based on cut-off value of 2.8mmol/L.     

Neonatal Mass Screening of Hereditary Metabolic Diseases in S. Paulo-Brasil

The authors report their experience in neonatal mass screening of hereditary metabolic disease in S. Paulo regarding hyperphenylalaninemia (by own programmation), others aminoacidophaties, congenital hypothyroidism, carbohydrates, mucopolysaccharides and heterozygotes for GM2-gangliosidosis type I (Tay-Sachs disease). The importance of the performing of such populational screening tests, even in developing countries is stressed.     

Status of Newborn Screening and Inborn Errors of Metabolism in India

Inborn errors of metabolism (IEM) are a heterogeneous group of genetic disorders that cause significant neonatal and infant mortality. Expanded newborn screening which detects these disorders at birth is the standard preventive strategy in most countries. Prospective studies to evaluate the impact of these in the Indian population are lacking. The imminent need to address this lacuna warrants a review of available pan India data, as well as efforts for a carefully conducted prospective assessment of the burden of IEM. Published data on IEM in the Indian population comprising universal prospective screening and screening in selected subgroups (patients admitted to pediatric/neonatal ICUs, patients with developmental delay/mental retardation) was collected through a systematic search. The primary focus was to get an estimate of the disease burden in the Indian population. A true prevalence of IEM in India is not available. The systematic review identifies and stratifies the various situations where IEM are found. Data collected by universal screening of the low risk population is essential to identify the true prevalence of IEM in India.     

MAPLE SYRUP URINE DISEASE

An infant with Maple Syrup Urine Disease was treated from six weeks of age with a synthetic diet containing carefully restricted quantities of branched chain aminoacids. There was a marked immediate improvement. At twelve weeks, gross vitamin deficiency developed and was corrected. The patient is now more than four-and-a-half years old, and although in reasonable general health is quite severely retarded, both mentally and physically. The problems of diagnosis, the biochemical basis of dietary treatment and the laboratory requirements for control are discussed in relation to the 55 previously published cases.     

上海地区遗传代谢病的新生儿筛查(英文)

Objectives Inborn errors of metabolism (IEM) has a diverse spectrum and different incidence in different countries, the early diagnosis at presymptomatic stage is imperative to benefic patient from sequelae. Phenylke-tonuria (PKU) / hyperphenylalaninemia (HPA) is the most common metabolism disorder in Shanghai as well as in other regions. The study is to further clarify the incidence of inborn errors of metabolism among newborn in Shanghai. Methods The dried blood spot specimens were collected from near 90 ...     

婴儿痉挛症患儿先天性代谢异常筛查

目的 探讨婴儿痉挛症(IS)患儿中不同先天性代谢异常情况,以利早期进行病因及对症治疗.方法 采用气相色谱-质谱法对30例IS患儿尿标本进行氨基酸、有机酸、脂肪酸、糖、核苷酸等代谢异常筛查,并进行尿常规、肝功能、血生化、脑部影像学及脑干听、视觉诱发电位等检查.结果 30例IS患儿中,23例(76.67％)尿筛查异常,其中甲基丙二酸尿症及酮性双羧酸尿症各4例(13.33％),非酮性双羧酸尿症3例(10.00％),苯丙酮尿症、戊二酸尿症、乳酸尿症和丙酸尿症各2例(6.67％),焦谷氨酸尿症、4-羟基苯丙酮酸尿症、色氨酸尿症及乳糖和半乳糖代谢异常各1例(3.33％).23例尿筛查异常病例均有不同程度的智力运动发育落后或倒退(100％).其中头颅CT或MRI异常12例(52.17％),脑干诱发电位异常20例(86.96％),肝功能异常3例(13.04％),血生化异常4例( 17.39％),尿常规酮体阳性(+～++)3例(13.04％).结论 先天性代谢异常是IS重要致病原因,对IS患儿应尽早进行先天性代谢异常筛查和遗传咨询,以助早期治疗及改善预后.     

Neonatal Screening for Inborn Errors of Metabolism Using Tandem Mass Spectrometry: Experience of the Pilot Study in Andhra Pradesh,India

Objective  

To estimate the prevalence of the Inborn Errors of Metabolism (IEM), evaluate biomarker distributions and determine benefits of screening for the inborn errors of metabolism in Andhra Pradesh, India, using Tandem Mass Spectrometry (MS/MS).     

Reliability of urine collection pads for routine and metabolic biochemistry in infants and young children

The aim of our study was to evaluate whether specifically designed urine collection pads give reliable results for routine and metabolic biochemistry tests in paediatric urine. Urine collected by bag or clean-catch from infants and children <2 yrs without metabolic disorders was divided into two aliquots, one of which was added to a collection pad, incubated for 15 min at 37°C (simulating in vivo collection conditions), then recovered by aspiration. Urine from adults with phaeochromocytoma and aqueous solutions of catecholamines were similarly treated. Routine, catecholamine, and metabolic analyses were performed on pad/non-pad aliquots. Selected metabolic analyses were also performed on pad/non-pad urine from patients with diagnosed inborn errors and urine containing added metabolites to simulate metabolic disorders. Routine tests (urea, electrolytes, creatinine, osmolality, calcium:creatinine, phosphate:creatinine, magnesium:creatinine, urate:creatinine [n = 32], oxalate:creatinine [n = 10]), and catecholamines (n = 12) showed good or acceptable concordance with no clinically significant pad/non-pad differences. Metabolic tests in infants and children without metabolic disorders all showed good pad/non-pad concordance for amino acids (n = 10), organic acids (n = 12), and glycosaminoglycans (n = 8). In patients with metabolic disorders (phenylketonuria [n = 1], homozygous/heterozygous cystinuria [n = 3], mucopolysaccharidoses II [n = 2] and III [n = 1], organic acid disorders [n = 6]) and urine containing added orotic acid to simulate urea cycle disorders, there was also good pad/non-pad concordance for diagnostic urinary metabolites. No extraneous organic acids were eluted from the pads. Sugar chromatography showed identical staining intensity in pad/non-pad samples. In conclusion, urine collection pads give reliable results for a wide range of routine and metabolic biochemistry tests in urine from paediatric patients.     

Hematopoietic stem cell transplantation for inborn errors of metabolism: A report from the Research Committee on Transplantation for Inborn Errors of Metabolism of the Japanese Ministry of Health,Labour and Welfare and the Working Group of the Japan Society for Hematopoietic Cell Transplantation

A total of 216 patients with IEM were treated by allogeneic HSCT in Japan from 1985 until 2010. The results of UCBT have improved, and the OS rate of UCBT (81.9%) was not different from those of RBMT (87.2%) or UBMT (73.9%) in 2000–2010. However, EFS rates in RBMT (73.2%) and UBMT (62.2%) were better than that in UCBT (49.5%), and the difference between RBMT and UCBT was significant (p = 0.01). The EFS rate of patients conditioned by RIC (74.6%) was comparable or slightly better than in those who underwent MAC with irradiation (57.9%) or without irradiation (54.2%) in 2000–2010. A more pronounced trend was observed toward differential EFS for UCBT in 2000–2010: RIC (62.9%), MAC with irradiation (20.0%), and MAC without irradiation (42.1%). The difference between RIC and MAC with irradiation was significant (p < 0.03). In summary, we report a Japanese registry analysis of HSCT for IEM with improving survival in UCBT. The introduction of RIC after 2000 was considered to contribute to this improvement. UCBT could be recommended for those who lack an HLA‐identical sibling donor.