Hypophosphatasia signs and symptoms can vary, but the most severe forms tend to occur before birth and in early infancy. Affected infants are born with short limbs, an abnormally shaped chest, and soft skull bones and additional complications in infancy include poor feeding and a failure to gain weight, respiratory problems, and high levels of calcium in the blood (hypercalcemia), which can lead to recurrent vomiting and kidney problems. These complications are life-threatening in some cases.