In general, there is a delay in physical development in males who have the genetic abnormality. Normal physical milestones such as sitting, crawling, and walking are achieved at older ages in Klinefelter’s patients. Weak muscles and reduced strength are usually observed in babies and toddlers with the syndrome. They tend to be taller with less muscular development, less hair on face and body, and broader hips. Also they usually have less energy than regular boys. In adulthood, XXY males are taller and tend to develop health issues such as autoimmune disorders, breast cancer, vein diseases, osteoporosis, and tooth decay. Male infertility is the most common issue in males with Klinefelter's disease.
XXY males usually have language problems. They learn to speak late and have problems using language to express thoughts. Also, Klinefelter's males have a harder time at reading and writing assignments.
Klinefelter's babies and teens tend to be quiet and shy. They have trouble keeping up with others at school and sports and usually have problems fitting within the group because of their lack of self-confidence. As adults, and with proper treatment, Klinefelter’s patients can live a normal life with friends, families, and develop normal social relationships.
