The phrase "if left unrepaired" is correct and usable in written English.
You can use it to show potential consequences of inaction, or to express a hypothetical situation. Example: The car's engine will suffer irreparable damage if left unrepaired.
If left unrepaired, the crack could grow to reach a critical length and threaten the integrity of the structure.
If repaired, this deliberately introduced damage allows biologists to edit the genome of cells, but if left unrepaired, it will cause cells to die.
If left unrepaired, these extensive terminal deletions would presumably lead to lethality, either due to the loss of essential genes or deleterious effects on chromosome transmission.
These big breaks can be lethal to cells if left unrepaired, or they can cause cancer or other diseases if repairs are shoddily done.
If left unrepaired, these insertions will result in TA→CG, GC→TA or AT→CG substitutions, respectively, following the subsequent round of DNA replication [18], [51].
Perhaps the most pernicious DNA lesion is the double-strand break (DSB) that can be lethal if left unrepaired [1], [2].
For example, if DSBs were left unrepaired, they could directly lead to permanent cell cycle arrest, apoptosis, or mitotic cell death [ 16].
Many patients with congenital heart disease and systemic-to-pulmonary shunts develop pulmonary arterial hypertension (PAH), particularly if the cardiac defect is left unrepaired.
Most famously, if one window was broken in a building and left unrepaired (his italics), soon all the other windows would be broken too, and criminal elements would take over.
Significant paint losses to the left side of the Second of May have been deliberately left unrepaired.
They wrote that if "a window in a building is broken and is left unrepaired, all the rest of the windows will soon be broken". The idea is that if a community tolerates a proliferation of small offenses — fare-dodging, vandalism, public urination — criminals will feel emboldened to commit more serious crimes like robbery and even murder.
