Screening tests and chromatography for the detection of inborn errors of metabolism

Investigação diagnóstica de erros inatos do metabolismo em um hospital universitário

“…O caso de hiperglicidemia não-cetótica também foi considerado falso-negativo, posto que a cromatografia de aminoácidos deveria ter indicado um aumento na concentração de glicina. Esse falso-negativo poderia ser explicado, entre outros fatores, por urina muito diluída ou ingesta protéica insuficiente (25) . Os dois casos de leucodistrofia metacromática que apresentaram teste de azul de toluidina alterado e cromatografia de MPS negativa se explicam pelo fato de a cromatografia de MPS ser mais sensível que o teste químico, não sendo a técnica de análise específica para esta doença.…”

Biochemical screening tests in the urine of mentally retarded children

“…The urinary excretion of excessive substrate, or deficient product of the missing enzyme can be identified by chemical methods, although several inherited disorders are associated with specific unusual odour, unusual urinary colour or with urinary crystals for easy identification of them (Table 1). [8][9][10][11][12][13][14][15][16] [8][9][10][11] These screening tests, that are simple, reliable, reproducible, inexpensive and suitable for developing country like India, are useful in the detection of relatively more common metabolic disorders such as phenyl ketonuria, histidinemia, galactosemia, Hartnup disease, maple syrup urine disease, homocystinuria, mucopolyssaccharidoses and metachromatic leukodystrophy. [12][13][14][15][16] They can be applied on a large population to be screened for specific metabolic disorders, thereby facilitating the detection of more number of affected subjects, prior to the onset of clinical problems.…”

“…[8][9][10][11][12][13][14][15][16] [8][9][10][11] These screening tests, that are simple, reliable, reproducible, inexpensive and suitable for developing country like India, are useful in the detection of relatively more common metabolic disorders such as phenyl ketonuria, histidinemia, galactosemia, Hartnup disease, maple syrup urine disease, homocystinuria, mucopolyssaccharidoses and metachromatic leukodystrophy. [12][13][14][15][16] They can be applied on a large population to be screened for specific metabolic disorders, thereby facilitating the detection of more number of affected subjects, prior to the onset of clinical problems. The factors like age, concentration of the urine, intake of drugs, type of food may interfere in these tests, thereby giving false results.…”