Final answer:
Stage 1 of Prader-Willi Syndrome (PWS) is characterized by signs and symptoms that manifest early in life, such as lack of muscle tone, poor sucking behavior, developmental delays, excessive eating, and cognitive deficits.
Step-by-step explanation:
Stage 1 of Prader-Willi Syndrome (PWS) is characterized by signs and symptoms that manifest early in life. These include lack of muscle tone, poor sucking behavior, developmental delays between 6 and 12 years of age, excessive eating, and cognitive deficits. Other signs and symptoms in this stage may include temperature instability, apnea, bradycardia, hypotension, difficulty feeding, irritability, limpness, and difficulty waking up when asleep.