Disturbances of Amino Acid Metabolism in Neurologic Disorders detected by fluorescent high performance liquid chromotograghy (HPLC) in Baghdad - IRAQ

Abstract

Background:Amino acid disorders are a major group of inborn error metabolism (IEM) with variable clinical presentation; its diagnosis constitutes a real challenge in a community with high consanguinity rate and no systematic newborn screening.

Objectives: to provide data about amino acid disorders detected in high-risk Iraqi children by using quantitative amino acid fluorescent high performance liquid chromatography (HPLC) analysis.

Type of the study: Cross-sectional study.

Methods: a descriptive cross sectional study from 1st February to 1st December 2014, at Neurological ward and clinic of the Children Welfare teaching Hospital, in Baghdad - Iraq. Plasma specimens of 500 patients, with clinical suspicion of inborn error of metabolism (IEM) because of unexplained neurological deficits, unexplained developmental delay, recurrent coma and/or Neuro-degeneration,  hair changes and/or lethargy, poor feeding, vomiting and selected cases of autistic spectrum syndrome or with positive screening, were analyzed for amino acids by high performance liquid chromatography (HPLC). The amino acid disorders were confirmed in fifty patients were; clinical data of patients were reported and analyzed statistically.

Results: out of 500 patients visiting the neurological outpatient and ward, clinical and neurological finding were recorded as well as the family history and/or other symptoms suggestive of aminoacidopathy, Sixty patients were confirmed their diagnosis as amino acid disorders, ten patients were excluded because they lost the follow up or  there is no solid base for a causal relationship between detected abnormal amino acids and neurological disorders, therefore only 50 patients were

enrolled in the study. Patients with Phenylketonuria were the most frequent 24 (48%), homocystinuria 14 (28%), maple syrup urine disease 9 (18%) & other amino acid disorder, (Citrullinemia, non-ketotic hyperglycinemia & Tyrosinemia) 1for each disorder (2%). Considerable delay in diagnosis was noticed which lead to variable neurological abnormalities  in most patients and the psychomotor delay was the main clinical presentation at time of diagnosis 34 (68%).

Conclusion: in the absence of newborn screening, the majority of Aminoacidopathies cases was still diagnosed clinically, but delayed. The importance of clinical awareness and accurate biochemical analysis were the key tools for diagnosis and the necessity for a comprehensive national newborn screening program.