INTRODUCTION:
The Biochemical Genetics Laboratory of the department of Pathology and Laboratory Medicine at the School of Medicine, American University of Beirut was initiated twenty-five years ago to provide diagnostic services of inborn errors of metabolism to the medical community in Lebanon and neighboring countries at large. The services are concerned with the evaluation and diagnosis of patients as well as families with inherited metabolic diseases, monitoring of treatment, and distinguishing heterozygote carriers from non-carriers by metabolic and enzymatic analysis of physiologic fluids and tissues.
State of the art technology is utilized in analysis which include qualitative detection and quantitative determination of diagnostic markers based on a variety of manual, automated colorimetric, fluorometric, chromatographic methods particularly HPTLC, HPLC, and GC/MS.
In contrast with Clinical Chemistry Laboratory, the Biochemical Genetics Laboratory is much more involved with the interpretation of results so that those are meaningful to the clinician and eventually the patient. Over the years, testing for metabolic disorders has evolved from highly specialized and fragmented information done primarily by research-oriented biochemists to an important component of patient care for all ages.
All reports contain an interpretation provided by the director of the laboratory. Referring physician are provided access to the medical staff for consultation regarding further testing for confirmatory purposes or in management of patients with inborn errors of metabolism.
Reporting:
Written interpretation is provided with each report. In case of an abnormality, normal values are reported for comparison. In case of enzyme deficiency, values for normal control are included. Telephone or fax is available.
Specimen Submission:
The type of specimen to be submitted is test-specific.
Kindly contact the laboratory for full information on patient preparation and type of sample and of preservative and condition of transfer while in transit.
SCOPE OF SERVICES:
At the turn of the 20th century, Sir Archibald Garrod coined the phrase �inborn errors of metabolism� to describe a group of lifelong disorders of metabolism that apparently resulted from a deficiency of an enzyme. Later, this definition was expanded by Rosenberg to include biochemical disorders that are genetically determined resulting from defects in the structure and hence function of protein molecules.
Inborn errors of metabolism (IEM) are individually rare, but collectively common. The incidence of a particular disorder may vary among different ethnic groups, but is always lower than common diseases of adult life. The cumulative incidence of IEM is about 1/5000 live births. This is equivalent to the incidence of juvenile diabetes mellitus. It has been estimated that 20% of infants presenting with �sepsis� picture in the absence of risk factors (such as prematurity, chorioamnionitis, etc..) have an IEM.
Over the years, the number of IEM has increased sharply. The advent of chromatography methods, quantitative amino acids and organic acid analysis, electrophoretic techniques of separation of proteins, radioisotopic, flurometric methods of enzyme activity measurements, cell culture technology, gas chromatography and mass spectrometry all has contributed to our capacity in detecting new disorders, analysis of metabolic sequences and predicting their genetic basis. Furthermore, molecular biology has added another opportunity to examine these disorders at the DNA level.
Infants presenting acutely with an IEM frequently remain undiagnosed until late in the course of their illness. Since many of these entities are preventable or even curable, the delay in the recognition and treatment of an IEM may have tragic consequences. Therefore , early diagnosis of an IEM can not be overestimated.
The Biochemical Genetics Laboratory offers a number of tests for the detection and diagnosis of IEM. Some of these tests are of screening capabilities such as plasma amino acids, urine organic acids. Others represent advanced screening tests as in carnitine, very long chain fatty acids. Definitive diagnosis assay in physiological fluids or tissue is also offered, such as specific metabolites that are pathognomonic of some disorders, and specific lysosomal enzymes.
Table one covers the tests that are offered by our laboratory, the associated disorder and the anatomic sample used for diagnosis.
Table two is concerned with the type of specimen needed in each test, covering the preservative or the anticoagulants and conditions of shipment while the sample is in transit to the Lab.