Question: What is (are) Sudden infant death syndrome ?
Answer: Sudden infant death syndrome (SIDS) is the unexpected, sudden death of a child under age 1 which cannot be explained after a thorough investigation is conducted. Infants who are affected by the condition generally appear healthy with no suspicious signs and symptoms prior to the incident. It is the leading cause of death in infants age 1 to 12 months old. The exact underlying cause of SIDS is unknown; however, scientists suspect that it is likely a multifactorial condition (associated with the effects of multiple genes in combination with lifestyle and environmental factors). Although there is no guaranteed way to prevent SIDS, the American Academy of Pediatrics has a published list of recommendations for risk reduction. Please click on the link to access this resource.
Source: GARD

Question: What are the symptoms of Sudden infant death syndrome ?
Answer: What are the signs and symptoms of Sudden infant death syndrome? The Human Phenotype Ontology provides the following list of signs and symptoms for Sudden infant death syndrome. If the information is available, the table below includes how often the symptom is seen in people with this condition. You can use the MedlinePlus Medical Dictionary to look up the definitions for these medical terms. Signs and Symptoms Approximate number of patients (when available) Apneic episodes in infancy - Sudden death - The Human Phenotype Ontology (HPO) has collected information on how often a sign or symptom occurs in a condition. Much of this information comes from Orphanet, a European rare disease database. The frequency of a sign or symptom is usually listed as a rough estimate of the percentage of patients who have that feature. The frequency may also be listed as a fraction. The first number of the fraction is how many people had the symptom, and the second number is the total number of people who were examined in one study. For example, a frequency of 25/25 means that in a study of 25 people all patients were found to have that symptom. Because these frequencies are based on a specific study, the fractions may be different if another group of patients are examined. Sometimes, no information on frequency is available. In these cases, the sign or symptom may be rare or common.
Source: GARD