Editing Birth defect (section)

=== Primarily metabolic ===
{{Main|Inborn error of metabolism}}
A '''congenital metabolic disease''' is also referred to as an [[inborn error of metabolism]]. Most of these are [[Genetic disorder#Single-gene|single-gene defects]], usually heritable. Many affect the structure of body parts, but some simply affect the function.<ref>{{Cite journal |last=Arnold |first=Georgianne L. |date=2018 |title=Inborn errors of metabolism in the 21st century: past to present |journal=Annals of Translational Medicine |volume=6 |issue=24 |pages=467 |doi=10.21037/atm.2018.11.36 |issn=2305-5839 |pmc=6331363 |pmid=30740398 |doi-access=free }}</ref>