A mother reports that her 4-month-old infant is lethargic, sleeps 18 hours a day, and snores. The nurse recognizes these signs are characteristic of what?

A. Hyperthyroidism: Hyperthyroidism is characterized by weight loss, insomnia, increased heart rate, irritability, and tremors, which are the opposite of the signs described in this case. Lethargy and excessive sleep are more typical of hypothyroidism, not hyperthyroidism. B. Tay-Sachs disease: Tay-Sachs disease is a genetic disorder that affects the nervous system, leading to developmental regression and symptoms like muscle weakness, loss of motor skills, and seizures. It does not typically present with lethargy and excessive sleep. C. Type 1 Diabetes Mellitus: Type 1 diabetes typically presents with symptoms such as polyuria, polydipsia, weight loss, and fatigue. While fatigue is common in type 1 diabetes, lethargy and excessive sleep, especially in a 4-month-old, are not indicative of it. D. Hypothyroidism: Hypothyroidism in infants can cause symptoms like lethargy, excessive sleep, snoring, poor feeding, and weight gain. It is a common condition in infants and can result in delayed development if left untreated.