Many families first notice 12q14 microdeletion syndrome when a baby grows more slowly than expected, with low birth weight and length and, over time, short stature that may prompt a growth evaluation. Doctors may also spot distinctive facial features or skeletal differences on early exams, and some children show delayed motor or speech milestones, which leads to genetic testing to look for the deletion. For many, the first signs of 12q14 microdeletion syndrome are flagged during infancy or early childhood check-ups, sometimes after an X-ray suggests reduced bone density or when growth hormone testing is considered.