Normal Variation: Low lipase and amylase levels can sometimes be seen in healthy individuals, especially if the levels are only slightly below the normal range. This could be due to variations in laboratory reference ranges or the timing of the blood sample in relation to meals.

Malnutrition: Malnutrition can lead to decreased production of digestive enzymes, including lipase and amylase, due to the lack of essential nutrients required for their production.
Chronic Pancreatitis: Although less common in adolescents, chronic pancreatitis can cause damage to the pancreas, leading to decreased enzyme production. However, other symptoms such as chronic abdominal pain would likely be present.
Cystic Fibrosis: This genetic disorder can affect the pancreas, leading to decreased production of digestive enzymes. However, it typically presents with respiratory and gastrointestinal symptoms early in life.

Pancreatic Cancer: Although extremely rare in adolescents, pancreatic cancer can cause a decrease in pancreatic enzyme production. It is crucial to rule out this diagnosis due to its severe prognosis.
Shwachman-Diamond Syndrome: A rare genetic disorder characterized by exocrine pancreatic insufficiency, bone marrow dysfunction, and skeletal abnormalities. It's essential to consider this diagnosis due to its potential for severe complications.

Johanson-Blizzard Syndrome: A rare genetic disorder that affects the development of the pancreas and other organs, leading to pancreatic insufficiency.
Pearson Syndrome: A rare mitochondrial disorder that can cause pancreatic insufficiency among other systemic manifestations.
Isolated Enzyme Deficiencies: Rare genetic conditions that result in the deficiency of specific enzymes, such as lipase or amylase, without affecting the overall function of the pancreas.