Usually, for liver function, doctors are only concerned about an elevated ALT result. 1.3 would be a below-normal ALT result. As you can see on this page about the ALT test, they don’t even list any liver diseases associated with low results, nor do they mention them. www.webmd.com/digestive-disorders/alanine-aminotransferase-test
But you should still discuss this with your doctor. There are one or two things that can cause low ALT, such as vitamin B6 deficiency or smoking, that they may feel you are or are not at risk for based on other symptoms. And obviously, if you’re experiencing whatever symptoms led them to call for a liver panel in the first place, then you need to speak to them.