2909
To evaluate the effect of altitude on adolescent growth and development , three groups of healthy , well - nourished youth of similar socioeconomic status and ethnic grouping who resided at sea level ( n = 1262 subjects ) , mid - altitude ( n = 1743 subjects ) , and high altitude ( n = 1137 subjects ) were studied .
 None
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: GENE 
Text: {0} 
 Entities:  
Answer:
 None