الفهرس 
Chemistry and classification of amino acidsOnly 14 pages are availabe for public view
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Abstract
A wide spectrum of inborn errors of amino acids metabolism are due to a single gene defect which may manifest immediately after birth or within few days or weeks after birth and can give rise to early onset of neonatal convulsions. Seizures can be attributed directly to the metabolic derangement itself or indirectly as a consequence of the metabolically caused brain dysgenesis or destructive brain lesions. Of the disorders of amino acid metabolism, defects of catabolism represent the largest group, but abnormalities also exist in amino acid biosynthesis and transport. Individual inborn errors of metabolism are rare disorders, most having incidence of less than 1 per 100,000 births. However, when considered collectively, the incidence may approach 1 in 800 to 2500 births. Most of the inborn errors of metabolism are transmitted as autosomal recessive genetic traits. Some inborn errors of metabolism, such as the urea cycle disorder, ornithine transcarbamylase (OTC) deficiency, are x-linked. A variety of inborn errors of amino acids metabolism that present with neonatal seizures can be identified including NKH, MSUD, sulphite oxidase deficiency, MTHFR deficiency, HHH syndrome, PGD deficiency, urea cycle defects, pyroglutamic aciduria, and congenital glutamine deficiency. Recent advances in diagnosis and treatment have improved significantly the prognosis for many infants with IEM of amino acids. Early clinical diagnosis is essential in ensuring that affected infants will receive the benefits of these advances. A high index of suspicion of IEM of amino acids should be raised in every sick neonate with convulsions. The first step in the evaluation of any sick neonate is the clinical assessment including history and physical examination. In the case of metabolic disorders, the family history is very significant, particularly if it reveals parental consanguinity, sibling deaths, and positive family history of similar previously poorly explained neonatal deaths. The majority of IEM that occur in the neonatal period are characterized by nonspecific signs and symptoms which are not useful in making a diagnosis but when observed in combination, without a known cause, are suggestive of such a diagnosis like convulsions, regression of milestones, mental retardation, ketosis, acidosis, persistent hypoglycemia, jaundice, organomegaly, dysmorphic features or coarse facial features.