Table 2.
The diagnosis and ICIMD classifications of COVID-19-positive patients.
| IMD Diagnosis | ICIMD subcategory | ICIMD category | Child n (%) | Adult n (%) | Overall n (%) |
|---|---|---|---|---|---|
| Phenylalanine hydroxylase deficiency: | Disorders of phenylalanine and tyrosine metabolism | Disorders of amino acid metabolism | 108 (48.4) | ||
| PKU on dietary treatment(n = 77) | n = 26 (50) | n = 51 (91.1) | |||
| HPA not requiring treatment (n = 21) | n = 16 (30.8) | n = 5 (8.9) | |||
| BH4-responsive PKU (n = 10) | n = 10 (19.2) | ||||
| Biotinidase deficiency | Disorders of biotin metabolism | Disorders of vitamin and cofactor metabolism | 24 (18.3) | 3 (3.3) | 27 (12.1) |
| Mucopolysaccharidosis | Disorders of glycosaminoglycan degradation | Disorders of complex molecule degradation | 10 (7.6) | 6 (6.5) | 16 (7.2) |
| Dyslipidemia | Disorders of lipoprotein metabolism | 5 (3.8) | 5 (5.4) | 10 (4.5) | |
| Maple syrup urine disease# | Branched-chain amino acids | Disorders of amino acid metabolism | 6 (4.6) | 3 (3.3) | 9 (4.0) |
| Methylmalonic acidemia# | Organic acidurias | Disorders of amino acid metabolism | 4 (3.1) | 2 (2.2) | 6 (2.7) |
| Homocystinuria⁎ | Sulfur-containing amino acids | Disorders of amino acid metabolism | 2 (1.5) | 3 (3.3) | 5 (2.2) |
| Glutaric aciduria type 1# | Organic acidurias | Disorders of amino acid metabolism | 2 (1.5) | 2 (2.2) | 4 (1.8) |
| Hereditary fructose intolerance⁎ | Disorders of galactose and fructose metabolism | Disorders of carbohydrate metabolism | 2 (1.5) | 2 (2.2) | 4 (1.8) |
| Fructose-1,6-diphosphatase deficiency⁎, # | Disorders of gluconeogenesis | Disorders of carbohydrate metabolism | 2 (1.5) | – | 2 (0.9) |
| Ornithine transcarbamylase deficiency⁎, # | Disorders of the urea cycle and hyperammonemias | Disorders of amino acid metabolism | – | 2 (2.2) |
2 (0.9) |
| Isovaleric acidemia⁎, # | Organic acidurias | Disorders of amino acid metabolism | 1 (0.8) | 1 (1.1) | 2 (0.9) |
| Lysinuric protein intolerance⁎# | Amino acid transport | Disorders of amino acid metabolism | 1 (0.8) | 1 (1.1) | 2 (0.9) |
| HMG-CoA lyase deficiency# | Disorders of ketone body metabolism | Disorders of fatty acid and ketone metabolism | 2 (1.5) | – | 2 (0.9) |
| X-linked adrenoleukodystrophy⁎ | Disorders of peroxisomal fatty acid oxidation | Disorders of lipid metabolism | 1 (0.8) | – | 1 (0.4) |
| Alkaptonuria⁎ | Disorders of phenylalanine and tyrosine metabolism | Disorders of amino acid metabolism | 1 (0.8) | – | 1 (0.4) |
| Mitochondrial acetoacetyl-CoA thiolase deficiency⁎# | Disorders of ketone body metabolism | Disorders of fatty acid and ketone metabolism | 1 (0.8) | – | 1 (0.4) |
| Chanarin-Dorfman syndrome⁎ | Disorders of glycerolipid metabolism | Disorders of lipid metabolism | 1 (0.8) | – | 1 (0.4) |
| Dihydropteridine reductase deficiency⁎ | Disorders of tetrahydrobiopterin metabolism | Disorders of vitamin and cofactor metabolism | 1 (0.8) | – | 1 (0.4) |
| Mitochondrial and cytoplasmic glycyl-tRNA synthetase deficiency⁎ | Disorders of mitochondrial aminoacyl-tRNA synthetases | Disorders of mitochondrial gene expression | – | 1 (1.1) |
1 (0.4) |
| Hepatic glycogen synthase deficiency⁎, # | Disorders of glycogen metabolism | Disorders of carbohydrate metabolism | 1 (0.8) | – | 1 (0.4) |
| Hyperprolinemia type 2⁎ | Disorders of ornithine, proline and hydroxyproline metabolism | Disorders of amino acid metabolism | 1 (0.8) | – | 1 (0.4) |
| HUPRA syndrome (SARS2)⁎ | Disorders of mitochondrial aminoacyl-tRNA synthetases | Disorders of mitochondrial gene expression | 1 (0.8) | – | 1 (0.4) |
| ITPA deficiency⁎ | Disorders of purine metabolism | Disorders of nucleobase, nucleotide and nucleic acid metabolism | 1 (0.8) | – | 1 (0.4) |
| Krabbe disease⁎ | Disorders of sphingolipid degradation | Disorders of complex molecule degradation | 1 (0.8) | – | 1 (0.4) |
| L-2-hydroxyglytaric aciduria⁎ | Disorders of mitochondrial metabolite repair | Disorders of metabolite repair/proofreading | – | 1 (1.1) |
1 (0.4) |
| LCHAD deficiency# | Disorders of mitochondrial fatty acid oxidation | Disorders of fatty acid and ketone metabolism | 1 (0.8) | – | 1 (0.4) |
| LPIN1 deficiency⁎, # | Disorders of glycerolipid metabolism | Disorders of lipid metabolism | 1 (0.8) | – | 1 (0.4) |
| MEGDEL syndrome⁎, # | Disorders of mitochondrial membrane biogenesis and remodeling | Disorders of organelle biogenesis, dynamics and interactions | 1 (0.8) | – | 1 (0.4) |
| Pompe disease | Other disorders of complex molecule degradation | Disorders of complex molecule degradation | 1 (0.8) | – | 1 (0.4) |
| Propionic acidemia# | Organic acidurias | Disorders of amino acid metabolism | 1 (0.8) | – | 1 (0.4) |
| PTPS deficiency⁎ | Disorders of tetrahydrobiopterin metabolism | Disorders of vitamin and cofactor metabolism | 1 (1.1) | 1 (0.4) | |
| Hypomyelinating leukodystrophy-10 (PYCR2)⁎ | Disorders of ornithine, proline and hydroxyproline metabolism | Disorders of amino acid metabolism | 1 (0.8) | – | 1 (0.4) |
| Trimethylaminuria⁎ | Disorders of methylamine metabolism | Disorders of peptide and amine metabolism | 1 (0.8) | – | 1 (0.4) |
| Tyrosinemia type 1⁎ | Disorders of phenylalanine and tyrosine metabolism | Disorders of amino acid metabolism | 1 (0.8) | – | 1 (0.4) |
| Tyrosinemia type 2⁎ | Disorders of phenylalanine and tyrosine metabolism | Disorders of amino acid metabolism | 1 (0.8) | – | 1 (0.4) |
| Citrullinemia type-1⁎, # | Disorders of the urea cycle and hyperammonemias | Disorders of amino acid metabolism | 1 (0.8) | – | 1 (0.4) |
| Combined oxidative phosphorylation deficiency 20 (VARS2)⁎, # | Disorders of mitochondrial aminoacyl-tRNA synthetases | Disorders of mitochondrial gene expression | 1 (0.8) | – | 1 (0.4) |
| Total | 131 (100) | 92 (100) | 223 (100) |
BH4: Tetrahydrobiopterin, HMG-CoA: 3-hydroxy-3-methylglutaryl coenzyme A, HPA: hyperphenylalaninemia, HUPRA: Hyperuricemia, pulmonary hypertension, renal failure, and alkalosis, ICIMD: International Classification of Inherited Metabolic Disorders, IMD: Inherited metabolic disorders, ITPA: Inosine triphosphatase, LCHAD: Long-chain 3-hydroxyacyl-CoA dehydrogenase, MEGDEL: 3-methylglutaconic aciduria, deafness, encephalopathy, and Leigh-like disease, PKU: phenylketonuria, PTPS: 6-pyruvoyl-tetrahydropterin synthase.
⁎
This paper is the first published record of COVID-19 in these disorders.
#
Disorders in which acute symptomatic metabolic decompensations are possible. Hereditary fructose intolerance, biotinidase deficiency and tyrosinemia type 1 were not included because the risk of decompensation is very low under treatment.