Researchers presented the clinical and genetic characteristics of 50 children with inborn errors of metabolism in an analysis published in the Indian Journal of Pediatrics.
Of these, 13 (26%) had lysosomal storage disorders such as Pompe disease and lysosomal acid lipase deficiency (LAL-D).
Eight (16%) had organic acidurias, 5 (10%) had mitochondrial disorders, 4 (8%) had urea cycle disorders, 4 (8%) had carbohydrate metabolism disorders, 4 (8%) had amino acidopathies, 3 (6%) had fatty acid oxidation defects, 3 (6%) had neurotransmitter deficiency disorders, and the remaining 4 (8%) had a miscellaneous disease.
The researchers first categorized the children looking at their predominant phenotype including encephalopathy, developmental delays or seizures, and neuroregression or organomegaly.
Read overviews of Pompe disease and LAL-D
More than half (62.5%) of children presenting with encephalopathy were diagnosed using acylcarnitine profiles and urine organic acids. A little more than half of the children with neuroregression were diagnosed with exome sequencing, and the majority (83.3%) of children with organomegaly were diagnosed with enzyme assay.
Those with developmental delays or seizures needed more tests. Half of the children had genetic variations.
The researchers concluded that it would be useful to first look at the acylcarnitine profiles and urine organic acids in children with acute encephalopathy. In those presenting with organomegaly, a specific enzyme assay should be carried out.
In children with neuroregression, developmental delays, seizures, movement disorders, and when metabolic tests and enzyme assays are not sufficient to reach a diagnosis, exome sequencing should be performed.
“Biochemical tests remain important as they can help to reclassify genetic variants of uncertain significance,” the authors said.
This study may not reflect the actual prevalence of different inborn errors of metabolism because it was retrospective from a single center.
“It is not an accurate reflection of the actual prevalence of various inborn errors of metabolism but identifies some common categories of [inborn errors of metabolism] seen in central India,” they concluded.
Passi GR, Wakchaure A, Jaiswal SP. Clinical and genetic spectrum of 50 children with inborn errors of metabolism from central India. Indian J Pediatr. Published online November 25, 2021. doi:10.1007/s12098-021-03958-4