Final answer:
Global developmental delays, such as in Prader-Willi syndrome, are typically recognized from birth up to 2 years with developmental delays usually becoming apparent between 6 and 12 years of age.
Step-by-step explanation:
The concern related to global developmental delay, such as that seen in Prader-Willi syndrome (PWS), can present early in life. In the context of PWS, signs like lack of muscle tone and poor sucking behavior may be noticed from birth to 2 years of age. Developmental delays typically become apparent between the ages of 6 and 12, with issues like excessive eating and cognitive deficits emerging later.
Addressing developmental concerns is critical for early intervention strategies. Although developmental delays can arise at different stages for varying reasons, noticing them as early as possible allows for better management and potential minimization of the long-term impact on the child's growth and educational development.