Aminoacidopathies and organic acidurias in Tunisia: a retrospective survey over 23 years
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Abstract
Background: Inborn errors of metabolism are neglected in developing countries because they are not as common as infectious and nutritional disorders. In Tunisia, no information is available on the incidence and epidemiological features of these inherited metabolic diseases.
Aims: To precise the profile of aminoacidopathies other than phenylketonuria and organic acidurias and to estimate their incidences in Tunisia.
Methods: Between 1987 and 2009, our laboratory received 13171 requests for analysis of patients with symptoms suggestive of inborn errors of metabolism. For these cases, ion exchange chromatography of free amino acids was performed on amino acids analyser. Urinary organic acids profiles were determined by gas chromatography-mass spectrometry.
Results: Abnormal cases were 370 (2.8%), divided into 212 cases of aminoacidopathies (57.3%) and 158 cases of organic acidurias (42.7%). The most frequent aminoacidopathies, were maple syrup disease (32.5%), tyrosinemia type I (28.8%) and nonketotic hyperglycinemia (16%). Methylmalonic aciduria (33.5%), propionic aciduria (18.4%) and 2-hyrdoxy glutaric aciduria (10.8%) were the most frequent organic acidurias. The incidences were calculated using the Hardy-Weinberg formula and were estimated at 1/13716 for maple syrup disease, 1/14804 for tyrosinemia type I, 1/16144 for methylmalonic aciduria and 1/23176 for propionic aciduria.
Conclusion: Aminoacidopathies and organic acidurias turned out to be highly frequent in Tunisia, mainly because of a high rate of consanguinity. We believe that they are underestimated. To improve their diagnosis, it is necessary to have available sophisticated equipment which would allow early treatment of patients.
Aims: To precise the profile of aminoacidopathies other than phenylketonuria and organic acidurias and to estimate their incidences in Tunisia.
Methods: Between 1987 and 2009, our laboratory received 13171 requests for analysis of patients with symptoms suggestive of inborn errors of metabolism. For these cases, ion exchange chromatography of free amino acids was performed on amino acids analyser. Urinary organic acids profiles were determined by gas chromatography-mass spectrometry.
Results: Abnormal cases were 370 (2.8%), divided into 212 cases of aminoacidopathies (57.3%) and 158 cases of organic acidurias (42.7%). The most frequent aminoacidopathies, were maple syrup disease (32.5%), tyrosinemia type I (28.8%) and nonketotic hyperglycinemia (16%). Methylmalonic aciduria (33.5%), propionic aciduria (18.4%) and 2-hyrdoxy glutaric aciduria (10.8%) were the most frequent organic acidurias. The incidences were calculated using the Hardy-Weinberg formula and were estimated at 1/13716 for maple syrup disease, 1/14804 for tyrosinemia type I, 1/16144 for methylmalonic aciduria and 1/23176 for propionic aciduria.
Conclusion: Aminoacidopathies and organic acidurias turned out to be highly frequent in Tunisia, mainly because of a high rate of consanguinity. We believe that they are underestimated. To improve their diagnosis, it is necessary to have available sophisticated equipment which would allow early treatment of patients.
Keywords:
Amino acids, pathology; organic, acidurias; inborn errors of metabolism; incidence; epidemiology/Tunisia; retrospective study##plugins.themes.academic_pro.article.details##
References
- Joshi SN, Hashim J, Venugopalan P. Pattern of inborn errors of metabolism in an Omani population of Arabian Peninsula. Ann Trop Paediatr 2002; 22:93-96.
- Teebi A, El-Shanti H. Consanguinity: implications for practice, research and policy. Lancet 2006; 367:970-71.
- Bittles AH. When cousins marry: a review of consanguinity in the Middle East. Prespect Hum Biol 1995; 1:71-83.
- Sanderson S, Green A, Preece MA, Burton H. The incidence of inherited metabolic disorders in the West Mildlands, UK. Arch Dis Child 2006; 91:896-99.
- Wasant P, Svasti J, Srisomsap C, Limmongkolkul S. Inherited metabolic disorders in Thailand. J Med Assoc Thai 2002; 85:S700-S9.
- Widhalm K. 25 years Austrian screening program for inborn errors of metabolism at the Vienna University. Wien Klin Wochenschr 1992; 104:510-3.
- Sadallah AA, Rached MS. Newborn screening: Experiences in the Middle East and North Africa. J Inherit Metab Dis 2007; 30:482- 9.
- Khemir S, Tebib N, Nasrallah F et al. Phenylketonuria in Tunisian institutions for the mentally handicapped. Arch Dis Child. 2009; 94:647-8.
- Khemir S, Elasmi M, Sanhaji H et al. Phenylketonuria is still a major cause of mental retardation in Tunisia despite the possibility of treatment. Clin Neurol Neurosurg 2011; 113: 727- 30.
- Hans JB, Marinus D, Johannis PK et al. Disturbances of amino acid metabolism: clinical chemistry and diagnosis. USA: Urban & Schwarzenberg Baltimore-Munich; 1981:450
- Monastiri K, Khairi H, Snoussi N, Ghannem H, Hajfredj A. Biométrie du nouveau né dans le Sahel Tunisien. Ann Pediatr 1994; 41:578-83.
- Moammar H, Cheriyan G, Mathew R, Al-Sannaa N. Incidence and patterns of inborn errors of metabolism in the Eastern Province of Saudi Arabia, 1983-2008. Ann Saudi Med. 2010; 30:271-7.
- Ozand PT, Devol EB, Gascon GG. Neurometabolic diseases at a national referral center: Five years experience at the King Faisal specialist hospital and research center. J Child Neurol 1992; S7:4- 11.
- Rashed M, Ozand PT, al Aqeel A, Gascon GG. Experience of King Faisal specialist hospital and research center with Saudi organic acid disorders. Brain Dev 1994; S16:1-6.
- Ozand PT. Diagnosis of inborn errors of metabolism by tandem mass spectrometry. Ann Saudi Med 1998; 18:234-8.
- Abdel-Hamid M, Tisocki K, Sharaf L, Ramadan D. Development, validation and application of tandem mass spectrometry for screening of inborn metabolic disorders in Kuwaiti Infants. Med Princ Pract 2007; 16:215-21.
- Carlo Dionisi V, Risso C, Burlina Ab et al. Inborn errors of metabolism in the Italian pediatric population: a retrospective survey. J Pediatr 2002; 3:321-7.
- Applegarth DA, Toone JR, Lowry RB. Incidence of inborn errors of metabolism in British Columbia, 1969-1996. Pediatrics 2000; 105:e10.
- Simoni RE, Oliveira SPH, Grassiano DM, et al. Screening for inborn errors of metabolism in high-risk children from Rio de Janeiro, Brazil. Early Hum Dev 1998; 50:305-11.
- Velázquez A, Vela-Amieva M, Cicerón-Arellano I et al. Diagnosis of inborn errors of metabolism. Arch Med Res 2000; 31:145-50.
- Han LS, Ye J, Qiu WJ et al. Diagnosis of inborn errors of metabolism using tandem mass spectrometry and gas chromatography mass spectrometry. Zhonghua Yi Xue Za Zhi 2008; 88:2122-6.