EXTENDED METABOLIC SCREEN
Facts:
Inborn errors of metabolism are hereditary diseases resulting from
incompetence in enzymatic reactions of intermediary metabolism.
More than 500 Inborn errors of metabolism are known today.
Each of these diseases alone is quite rare, but as a group,
they affect about 1-2% of newborns and therefore pose a significant
health problem.
Inborn errors of metabolism causing clinical manifestations in the
neonatal period are usually severe, non-specific, and are often lethal
if proper therapy is not quickly initiated.
Inborn errors of metabolism should be considered in severely ill neonate with:
1- Lethargy, poor feeding, convulsions, vomiting, coma.
2- Clinical deterioration in a previously healthy neonate.
3- Death in neonatal period especially if there is positive sib death
or consanguineous marriage.
Inborn errors of metabolism should be suspected in children with:
1- Unexplained mental retardation, developmental delay or convulsions.
2- Intermittent episodes of unexplained vomiting, acidosis, mental deterioration
or coma.
3- Hepatomegaly.
Acts:
Extended metabolic screen is a simple quick test that utilizes few drops
of blood to screen for more than 30 Inborn errors of metabolism including:
1- Acylcarnitine/ carnitine profile for detection of:
– Fatty acids oxidation disorders.
– Organic acids disorders (Methylmalonic acidemia, propionic
acidemia, multiple carboxylase deficiency, isovaleric acidemia).
2- Amino Acid profile for detection of:
– Phenyleketonuria, tyrosinemia, MSUD, homocystinuria and hypermethionemia.
– Urea cycle disorders.
3- Galactose- (Gal and Gal-1-p) for detection of galactosaemia.
4- Biotinidase enzyme for detection of biotinidase deficiency.
SO Extended Metabolic Screening is strongly indicated for diagnosis
of Inborn errors of metabolism as early treatment may prevent or at least decrease the serious effects associated
with these disorders.
Some Metabolic Disorders Detected by
Extended Metabolic Screen
Amino Acid Disorders:
Phenyleketonuria
Tyrosinemia
Maple Syrup Urine Disease (MSUD)
Classical homocystinuria.
Hypermethioninemia
Urea Cycle disorders:
Citrullinemia
Arginosuccinic Aciduria
Arginase Deficiency
Organic Acid Disorders:
Methylmalonic Acidemias
Propionic Acidemia
Isovaleric Acidemia
Multiple Carboxylase Deficiency
Glutaric Acidemia- Type 1
Mitochondrial Acetoacetyle-CoA Thiolase Deficiency
Biotinidase Deficiency
Fatty Acid Oxidation Disorders
Carnitine/Acylcarnitine Translocase Deficiency
Long Chain Acyle- CoA Dehydrogenase Deficiency (LCHAD)
Medium Chain Acyle-CoA Dehydrogenase Deficiency (MCAD)
Short Chain Acyle-CoA Dehydrogenase Deficiency
Very Long Chain Acyle-CoA dehydrogenase Deficiency
Glutaric Acidemia –Type II
Galactosemia
