Clinical and biochemical profiles of Filipino patients with distal urea cycle disorders detected by abnormal expanded newborn screening

Objective@#The study is a retrospective review which provides preliminary data on the correlation between biochemical profiles and initial clinical manifestation of patients diagnosed to have argininosuccinate synthetase deficiency (ASSD) and argininosuccinate lyase deficiency (ASLD) detected by expanded newborn screening (ENBS). @*Methods@#This is a study of five distal UCD patients initially detected by elevated citrulline on ENBS. Medical charts of the patients were reviewed. The initial clinical manifestations of the patients were correlated with results of biochemical tests. @*Results@#There were four cases of ASLD and one case of ASSD reviewed in this study. All cases of ASLD were confirmed by the presence of argininosuccinic acid (ASA) in the urine metabolic screen (UMS). The plasma citrulline level of the ASSD patient is significantly elevated as compared to the ASLD patients (2,690 µmol/L; NV: 10-45 µmol/L). The ASSD patient and one ASLD patient were symptomatic within the first six days of life. Both presented with significantly elevated plasma ammonia, citrulline and glutamine levels. Three ASLD patients were asymptomatic on initial screening. @*Conclusion@#ENBS has shown importance in the early detection and management of ASSD and ASLD. Early initiation of management may prevent hyperammonemic crises. Long term outcome studies are needed to look into the correlation of neurodevelopmental outcome with lifelong accumulation of citrulline and glutamine in ASSD and ASA in ASLD.

Clinical, biochemical, and radiologic characteristics of Filipino patients with Glutaric Aciduria Type 1

Introduction@#Glutaric Aciduria Type 1 (GA1) is an inborn error of metabolism included in the expanded newborn screening of the Philippines. This inborn error of metabolism is caused by glutaryl-CoA dehydrogenase deficiency which is important in the catabolism of lysine, hydroxylysine and tryptophan. @*Objective@#This paper aimed to present the baseline data of patients with GA1 in the Philippines by describing the clinical, biochemical, and radiologic characteristics of Filipino patients with biochemically-confirmed GA1 seen at the Philippine General Hospital from January 2010 to December 2017. The cases of this condition have been increasing and are expected to increase even more with the full coverage of the expanded newborn screening. @*Methods@#This study was a review of the medical records of the GA1 patients managed by the Division of Clinical Genetics, Department of Pediatrics of the Philippine General Hospital (PGH). Biochemical parameters, developmental assessment, neurologic assessment, and radiologic features of the patients were reviewed and analyzed. @*Results@#There were a total of 7 patients with GA1 at the PGH from January 2010 to December 2017. Of the 7 patients, 4 were diagnosed by expanded newborn screening (ENBS) and 3 patients had disease onset prior to diagnosis. Clinical features noted in screened patients include global developmental delay (75%), seizures (50%), dystonia (50%), truncal hypotonia (25%) and macrocephaly (25%). In unscreened patients, macrocephaly was present in 66.67 %, while the other clinical features were present in all of them. Four of the 7 patients had infection and one had vaccination, which may have led to a metabolic crisis and subsequent onset of symptoms. The plasma levels of glutarylcarnitine (C5DC) range from 2.81 to 4.58 umol/L. Grossly elevated urinary excretion of glutarylcarnitine were noted in all patients. Urinary glutaconic acid and 3-hydroxyglutaric acid were also detected in all patients. Both striatal and extra-striatal abnormalities were present in screened and unscreened patients on neuroimaging. The most common being the widening of the sylvian fissure, cerebral atrophy, and white matter abnormalities. @*Conclusion@#Although newborn screening of GA1 and initiation of early management of this condition have been seen important, it is still prudent to continue the appropriate management and to provide timely aggressive emergency treatment in order to improve outcome of patients with GA1. With the recent Philippine Health Insurance (PhilHealth) coverage of the expanded newborn screening, it is expected that physicians will encounter more of the metabolic disorders, including GA1. Hence, it is important that physicians be more aware of the presenting signs and symptoms of this disorder, as well as its management, which can further improve the neurologic and developmental outcomes of these patients.

Incidence of Inborn Errors of Metabolism by Expanded Newborn Screening in a Mexican Hospital

Abstract Newborn screening for the detection of inborn errors of metabolism (IEM), endocrinopathies, hemoglobinopathies, and other disorders is a public health initiative aimed at identifying specific diseases in a timely manner. Mexico initiated newborn screening in 1973, but the national incidence of this group of diseases is unknown or uncertain due to the lack of large sample sizes of expanded newborn screening (ENS) programs and lack of related publications. The incidence of a specific group of IEM, endocrinopathies, hemoglobinopathies, and other disorders in newborns was obtained from a Mexican hospital. These newborns were part of a comprehensive ENS program at Ginequito (a private hospital in Mexico), from January 2012 to August 2014. The retrospective study included the examination of 10 000 newborns' results obtained from the ENS program (comprising the possible detection of more than 50 screened disorders). The findings were the following: 34 newborns were confirmed with an IEM, endocrinopathies, hemoglobinopathies, or other disorders and 68 were identified as carriers. Consequently, the estimated global incidence for those disorders was 3.4 in 1000 newborns; and the carrier prevalence was 6.8 in 1000. Moreover, a 0.04% false-positive rate was unveiled as soon as diagnostic testing revealed negative results. The most frequent diagnosis was glucose-6-phosphate dehydrogenase deficiency; and in the case of carriers, it was hemoglobinopathies. The benefit of the ENS is clear as it offers prompt treatment on the basis of an early diagnosis including proper genetic counseling. Furthermore, these results provide a good estimation of the frequencies of different forms of newborn IEM, endocrinopathies, hemoglobinopathies, and other disorders at Ginequito.