Biochemical screening tests in the urine of mentally retarded children


  • Kannan Ramamoorthy Department of Paediatrics, Government Thiruvarur Medical College and Hospital, Thiruvarur, Tamil Nadu, India
  • Agora Shivan Shanmuga Sundaram Department of Paediatrics, Government Thiruvarur Medical College and Hospital, Thiruvarur, Tamil Nadu, India



Biochemical screening tests, Mentally retarded children, Urine samples


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.


Bearn AG, Miller ED. Archibald carred and the development of the concept of inborn errors of Metabolism. Bull Hist Med. 1979;53:315.

Ladubn Zannoni VA, Laster L, Seeg Miller JE. The nature of the defect in tyrosine metabolism in Alcaptonoria. J Biol chem. 1958;230:251.

Sutton HE, Wagner RP. Mutation and enzyme function humans. Ann Rev Genet. 1975;9:187.

Harris H. The principles of human biochemical genetics. Ed.3 Amesterdon, North Holand: Publishing Co;1980:12.

Datar CA, Apte BN. Screening of previously undiagnosed pediatric cases of mental retardation and autism for specific metabolic disorders. Bombay Hospital J. 2008;50(4):560-5.

Gupta A. To err is Genetics: diagnosis and management of inborn errors of metabolism (IEM). Chapter 32. 415-423.

Bondy, Rosenberg. Metabolic control and disease. 8th Ed. 1981: 91.

Smith I. Chromatographic and Electrophoretic Techniques. Volume 1. Chapter 1. William Heinemann Medical Books, London: Interscience Publishers; 1976.

Smith I. Chromatographic and Electrophoretic Techniques. Volume 1. Chapter 5. William Heinemann Medical Books, London: Interscience Publishers; 1976.

Henry RJ. Clinical chemistry. Principles and techniques. Chapter 13. 1964.

1Smith I. Chromatographic and Electrophoretic Techniques. Volume 1. Chapter 11. William Heinemann Medical Books, London: Interscience Publishers; 1976.

Stuber A. screening test and chromatography for the detection of inborn error of metabolism. Clin Chemica Acta. 1972;36:309.

Stanbury JB, Wyngaarden JB, Fredrickson DS. The Metabolic Basis of Inherited Disease. 3rd edition. New York: McGraw-Hill Book Co; 1972: 275.

La Du BN, Howell RR, Jacoby GA, Seegmiller JE, Sober EK, Zannoni VG, et al. Clinical and biochemical studies in two cases of histindinemia. Pediatrics. 1963;34:216.

Auerbach VH, DiGeorge AM, Baldridge RC, Tourtellotte CD, Brigham MP. Histidinemia: a deficiency in histidase resulting in the urinary excretion of histidine and of imidazolepyruvic acid. J Pediatr. 1962;60:487-97.

Pennock A. A review and selection of simple laboratory methods used for the study of glycosaminoglycin excretion and the diagnosis of mucopolysaccharidosis. J Clini Path. 1976;29:111.

Jailkhani R, Patil VS, Laxman HB, Shivashankara AR, Kulkarni SP, Ravindra MS. Selective Screening For Inborn Errors Of Metabolism In Children: Single Centre Experience From Karnataka. J Clin Diagnostic Res. 2008;2:952-8.

Phornphutkul C, Introne WJ, Perry MB, Bernardini I, Murphey MD, Fitzpatrick DL et al. Natural history of alkaptonuria. N Engl J Med. 2002;347:2111-21.

Yadav GC, Reavey PC. Aminoacidopathies: a review of 3 years experience of investigations in a Kuwait hospital. J Inherit Metab Dis. 1988;11(3):277-84.

Milunsky A. The prevention of genetic disease and mental retardation. Philadelphia: WB Saunders; 1975; 38-39.

Targum SD, Lang W. Neurobehavioral problems associated with phenylketonuria. Psychiatry (Edgmont). 2010;7(12):29-32.

Phenylketonuria (PKU). Available at: Accessed on 10 February 2018.

Martins AM, Dualibi AP, Norato D, Takata ET, Santos ES, Valadares ER, et al. Guidelines for the Management of Mucopolysaccharidosis Type I. J Pediatr. 2009;155(4):32-46.

Lin H, Chuang C, Chen M, Lin S, Chiu P, Niu D, et al. Natural History and Clinical Characteristics of Taiwanese Patients with Mucopolysaccharidosis II: Data from the Hunter Outcome Survey (HOS). J Inborn Err Metabolism Screening. 2016;4:1–82.

Dundar M, Uzak AS, Erdogan M, Akbarova Y. Prediction, prevention and personalisation of medication for the prenatal period: genetic prenatal tests for both rare and common diseases. EPMA J. 2011;2(2):181-95.

Chung W. Neuromuscular disorders of infancy, childhood, and adolescence (Second Edition) A Clinician's Approach. In: Darras BT, Royden Jones H, Ryan MM, De Vivo DC, editors. Elsevier; 2015: 17–31.






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