Many families first notice 14q11.2 microdeletion syndrome in infancy or early childhood when growth seems slower than expected, feeding is difficult, or developmental milestones like sitting, first words, or walking arrive later than peers. Doctors may pick up the first signs of 14q11.2 microdeletion syndrome at a routine check-up because of low muscle tone, subtle facial features, or emerging learning and speech differences, which then prompts genetic testing. Some children are identified through prenatal testing or after birth due to congenital differences, but for many, the condition is first noticed when delays or behavioral features—sometimes including traits seen in autism spectrum conditions—become clear in the toddler years.