There are several different deformities of the sternum, but the most common two are Pectus Carinatum (thebreastbone points outward) and Pectus Excavatum(the breastbone caves in.) It can be hereditary and it's not unusual to have other family members who have teh same traits. Generally speaking, the one that points out is not a health problem at all,simply a cosmetic issue. The Pectus Excavatum, in most affected people is also generally shallow and not much of an issue, except for the way it looks. In a small number of people, mainly boys, the pectus excavatum will progress to the point of needing surgery if the lungs or heart is compromised.
We have several men in the family who have Pectus excavatum--my dad, my two sons, and one nephew. The only one who has needed repair was my oldest son, John. His pectus was extremely deep, as deep as an adult fist, causing partial collapse of his lung and a heart murmur from the sternum rubbing on the heart. His chest Xray looked like he had a large pancake in his rib cage, his heart was smashed so flat.
We had his pectus repaired at Miami Children's hospital when he was 5yo and he did beautifully. Of course, it will always look different. He has a 6-7 inch horizontal scar on his chest and his chest looks puny due to the ribs being misshapen. The pressure of the deformity caused his heart to twist almost backwards--it's under his left arm now, rather than to the left of his sternum. But he is healthy as a horse.
I wouldn't put my other son through this for his much milder pectus. This was major-major surgery, and very painful, like having a bypass. But I'm glad we did it for John before he developed other problems.