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Detection of inborn errors of metabolism in patients of pediatric intensive care units of Porto Alegre, Brazil: comparison of the prevalence of such disturbances in a selected and an unselected sample

Moacir Wajner^I; Clóvis Milton Duval Wannmacher^I; Daisson Gaidzinski^II; Carlos Severo Dutra-Filho ^I; Marili Schar Buchalter ^I; Roberto Giugliani^I

^IDepartamento de Bioquímica, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, 90000 Porto Alegre, RS, Brasil. Send correspondence to M.W.
^IIDepartamento de Pediatria, Pontifícia Universidade Católica do Rio Grande do Sul, 90000 Porto Alegre, RS, Brasil

ABSTRACT

A metabolic screening of urine and blood samples obtained at neonatal and regular pediatric intensive care units (ICU) from 232 unselected children and from 59 children selected on the basis of symptoms and signs suggesting inborn errors of metabolism (IEM) was carried out in Porto Alegre, Brazil. A battery of simple chemical urine tests including a test for methylmalonic acid, analysis of blood and urine amino acid patterns by one-dimensional paper chromatography and electrophoresis, analysis of sugar patterns by thin-layer chromatography (TLC) in urine samples showing the presence of reducing substances, and more accurate techniques for amino acid and organic acid quantitation were employed when necessary. The frequency of metabolic disorders found in the selected sample (4 out of 59 patients) was significantly higher (P <0.05) than in the unselected group (1 out of 232 children). The high incidence of prematures, severe malnutrition and of infectious diseases in the latter group of patients may have contributed to these findings. We found that acidosis and convulsions followed by liver dysfunction were the most prominent findings for the patients detected to have metabolic disturbances. These results suggest that the search for inherited metabolic diseases in severely ill children in a developing country should be specially reserved to patients selected on the basis of more specific symptoms.

Keywords: inborn errors; pediatric; disturbances.

REFERENCES

Buist, N.R.M. (1968). Set of simple side-room urine tests for detection of inborn error of metabolism. Br. Med. J. 2: 745-749.

Chalmers, R.A., Purkiss, P. and Watts, R.W.E. (1980). Screening for organic acidurias and amino acidopathies in newborns and children. J. Inherited Metab. Dis. 3:27-43.

Chalmers, R.A. and Watts, R.W.E. (1972). The quantitative extraction and gas-liquid chromatographic determination of organic acids in urine. Analyst 97: 958-967.

Dhareshwar, S.S., Ambani, L.M., Suchak, R.H. and Danthi, V. (1982). Inborn errors of metabolism in acutely sick children. Indian J. Med. Res. 76: 716-722.

Henry, R.J. (1965). Clinical Chemistry: Principles and Technics. Harper & Row, New York, pp. 697.

Holmgren, G., Jeppson, J.O. and Samuelson, G. (1970). High-voltage electrophoresis in urinary amino acid screening. Scand. J. Clin. Lab. Invest. 26: 313-318.

Kneer, J., Jakobs, C. and Monch, F. (1983). Selective screening for organic acidurias. In:Neonatal Screening (Naruse, H. and Irie, M., eds.). Excerpta Medica, Amsterdam, Oxford, Princeton, pp. 412-413.

Krieger, I.E., Nigro, M., Sarnaik, A. and Taqi, Q. (1981). Screening of high risk infants for metabolic disease in a metropolitan hospital. J. Inherited Metab. Dis. 4: 81-82.

Lehnert, W. and Niederhoff, H. (1984). Seven years of experience with selective screening for organic acidurias. Eur. J. Pediatr. 142: 208-210.

Menzies, I.S. and Seakins, J.W.T. (1976). Sugars. In: Chromatographic and Electrophoretic Techniques (Smith, I. and Seakins, J.W.T., eds.). Vol. I. William Heinemann Medical Books Ltd., London, pp. 183-217.

Reddy, O.S. (1977). Screening for metabolic disorders in children aminoacidopathies. Indian J. Pediatr. 44: 25-38.

Scriver, C.R., Davies, E. and Cullen, A.M. (1964). Application of a simple micromethod to the screening of plasma for a variety of aminoacidopathies. Lancet II: 230-232.

Spackman, D., Stein, W.H. and Moore, S. (1958). Automatic recording apparatus for use in the chromatography of amino acids. Anal. Chem. 30: 1190-1206.

Tanaka, K. and Hine, G. (1983). Organic acidemia screening using gas chromatography alone: use of gc retention indices of 163 metabolically important acids for identification. In: Neonatal Screening (Naruse, H. and Irie, M., eds.). Excerpta Medica, Amsterdam, Oxford, Princeton, pp. 404-409.

Thomas, G.H. and Howell, R.R. (1973). Selected Screening Tests for Genetic Metabolic Diseases. Year Book Medical Publ., Chicago, pp. 101.

Vaca, G., Hernandez, A., Ibarra, B., Velazquez, A., Olivares, N., Sanchez-Corona, J., Medina, C. and Cantu, J.M. (1981). Detección de errores congénitos del metabolismo en 1,117 pacientes estudiados por sospecha de enfermedad hereditaria. Arch. Invest. Méd. 12: 341-348.

Wannmacher, C.M.D., Wajner, M., Giugliani, R., Giugliani, E.R.J., Costa, M.G. and Giugliani, M.C.K. (1982). Detection of metabolic disorders among high risk patients. Rev. Brasil. Genet. V: 187-194.

Wells, M.G. (1969). A simple rapid method for the determination of alpha-amino acids in urine. Clin. Chim. Acta 25: 27-29.