Biochemical screening tests in the urine of mentally retarded children

Kannan Ramamoorthy, Agora Shivan Shanmuga Sundaram


Background: Inborn errors of metabolism (IEMs) are a group of genetically determined disorders caused by mutant genes that in turn produce abnormal enzyme to affect metabolism of a nutrient and a significant association has been found between mental retardation and IEMs. The present study was conducted on mentally retarded children to diagnose IEM using a panel of simple biochemical tests to be confirmed by various chromatographic techniques.

Methods: The study was done on 300 mentally retarded children admitted for treatment in the Paediatric Department, Govt R. M. Hospital, Thanjavur. Complete clinical history was collected in a predesigned proforma. 50 ml of urine samples was collected from each patient in a clean sterilized bottle and analysed for a series of biochemical tests using a standard protocol. All the observations were collected and analysed.

Results: Male dominance was seen in the study (65.3%). Out of 300, 93 children (31%) of the total were with the family history of consanguinity and the of rest 201 (69%) cases of non-consanguinity, delayed labour was found to be more common (50%). 4 children were affected with metabolic disorders (1.33%) i.e. 1 case was with phenyl ketonuria and other 3 cases with mucopolysaccharidoses.

Conclusions: The study identified four cases of IEM in the mentally – retarded children with underlying molecular defects and also paved a path to save the children in the case of phenylketonuria by the treatment i.e. diet low in phenyl alanine.


Biochemical screening tests, Mentally retarded children, Urine samples

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