Absence Seizures: This is the most likely diagnosis given the presentation of staring off for 1 minute, which is a classic symptom of absence seizures. Absence seizures are a type of epilepsy characterized by brief, sudden lapses in consciousness.

Daydreaming or Attention Deficit: Young children, especially at the age of 3, might have short attention spans and could appear to be staring off into space as they daydream or lose focus.
Autism Spectrum Disorder (ASD): Children with ASD might exhibit staring behaviors as part of their condition, which could be mistaken for absence seizures.
Benign Childhood Epilepsy: This condition can present with various seizure types, including those that might resemble absence seizures.

Complex Partial Seizures: Although less common in this age group, complex partial seizures can present with staring and impaired consciousness. Missing this diagnosis could lead to inadequate treatment and increased risk of seizure recurrence.
Metabolic Disorders: Certain metabolic disorders can cause seizures or seizure-like behaviors. Identifying and treating these conditions is crucial to prevent long-term neurological damage.
Intracranial Pathology (e.g., Tumors, Cysts): Although rare, staring spells could be a symptom of an underlying intracranial pathology. Missing this diagnosis could have severe consequences, including increased intracranial pressure and neurological deficits.

Landau-Kleffner Syndrome: A rare condition characterized by the sudden onset of aphasia (loss of language skills) and seizures, which could initially present with staring spells.
Lennox-Gastaut Syndrome: A severe form of epilepsy that can present with various seizure types, including atonic seizures that might resemble staring spells.
Mitochondrial Disorders: Certain mitochondrial disorders can cause neurological symptoms, including seizures or seizure-like behaviors. These conditions are rare but important to consider in the differential diagnosis due to their potential for significant morbidity.