Question: How many patients with shellfish allergies died when they were under 12 years old? Please give their full names.
SQL: SELECT T1.first, T1.last FROM patients AS T1 INNER JOIN allergies AS T2 ON T1.patient = T2.PATIENT WHERE T2.DESCRIPTION = 'Shellfish allergy' AND CAST((strftime('%J', T1.deathdate) - strftime('%J', T1.birthdate)) AS REAL) / 365 < 12