Table 4.
Summary of all treatable IEMs (n = 38, 57%) that can be detected by ‘1 st -tier’ metabolic screening tests, which are affordable and accessible, with the potential to identify multiple IEMs
| Blood tests | |||
|---|---|---|---|
| Acylcarnitine profiles (n = 3) | ● MCAD deficiency | ||
| ● SCAD deficiency | |||
| ● VLCAD deficiency | |||
| Free-to-total serum/plasma carnitine (n = 1) | ● Carnitine palmitoyltransferase I deficiency | ||
| Plasma Amino Acids (n = 10) | ● Argininemia | ● Hartnup disease | ● MTHFR Deficiency (&tHcy) |
| ● Argininosuccinate lyase deficiency | ● HHH syndrome | ● Ornithine transcarbamylase deficiency | |
| ● Citrullinemia type I | ● Maple syrup urine disease | ● Phenylketonuria (PKU) | |
| ● Citrullinemia, type II | |||
| Plasma cholesterol (n = 1) | ● Cerebrotendinous xanthomatosis (CTX) | ||
| Serum copper & ceruloplasmin (n = 2) | ● Menkes Disease (& urine deoxypyridinoline) | ||
| ● Wilson Disease (& urine copper) | |||
| Urine tests | |||
| Urine creatine metabolites (n = 1) | ● GAMT deficiency | ||
| Urine oligosaccharides (n = 1) | ● Fucosidosis | ||
| Urine organic acids (n = 17) | ● 3-Methylglutaconic aciduria type 1 | ● Ethylmalonic encephalopathy (& ACP) | ● MHBD deficiency |
| ● 3-Methylcrotonyl-CoA carboxylase (MCC) deficiency (& ACP) | ● SSADH | ● HMG-CoA lyase deficiency | |
| ● β-Ketothiolase deficiency | ● Glutaric aciduria type I | ● mHMG-CoA synthase deficiency | |
| ● Cobalamin deficiencies (& PAA) | ● Holocarboxylase synthetase deficiency | ● Multiple acyl-CoA-dehydrogenase deficiency (MADD) | |
| ● Cystathionine β-synthase deficiency | ● Isovaleric academia | ● Propionic academia | |
| ● Methylmalonic academia | ● SCOT deficiency | ||
| Urine purines & pyrimidines (n = 2) | ● Lesch-Nyhan syndrome | ||
| ● Molybdenum cofactor deficiency |
Abbreviations include: ACP acylcarnitine profiles, tHcy total homocystine, PAA plasma amnio acids.