Table 5.

Diagnoses in 84 children with progressive encephalopathy

	Diagnoses (n)
Lysosomal	I cell disease (1), alpha-Mannosidosis (1), MLD (3), MPS1 (4), MPS2 (1), MPS3 (1), NCL congenital [19] (3), NCL3 (4), NPC (3), Salla disease (1), Sandhoff disease (1)
Mitochondrial	Leigh disease (3)
Peroxisomal	Adrenoleukodystrophy X-linked (2)
Organic aciduria	2-methylbutyryl CoA dehydrogenase deficiency [20]a (1), glutaric aciduria (1), L2 hydroxy glutaric aciduria (2), methyl malonic aciduriab (2), multiple carboxylase deficiency (2), propionic aciduria (3)
Fatty acid beta oxidation	MTP (2), MCAD (2), VLCAD (1), unspecified (1)
Urea cycle	CPS1 (3), OCT (1)
Other	Galactosemia (4), Unspecified intermediate metabolism (2)
Neurodegenerative, specified	Ataxia teleangiectasia (1), Cockayne syndrome (2), megaloencephalic leukoencephalopathy with subcortical cysts (1), microphthalmia brain atrophy disease [22] (3), pontocerebellar hypoplasia-infantile spinal muscular atrophy [23] (1), Schinzel Gideon syndrome (2)
Neurodegenerative, unspecified	Mainly affecting: basal ganglia (1), cerebellum (8), cerebellum and basal ganglia (1), cerebellum and brain stem (1), cerebral cortex (3), cerebral white matter (3)
Infectious	HIV encephalopathy (2)

CPS: carbamyl phosphate synthetase; HIV: human immune deficiency virus; MCAD: medium-chain acyl CoA dehydrogenase; MLD: metachromatic leukodystrophy; MPS: mucoplysaccharidosis; MTP: mitochondrial trifunctional protein; NCL: neuronal ceroid lipofuscinosis; NPC: Niemann Pick disease type C; OCT: ornithine transcarbamylase; VLCAD: very-long-chain acyl CoA dehydrogenase

^aThe clinical course in this disease is uncertain

^bEnzymatic diagnosis unknown