<s>[INST] <<SYS>> This is a medical question of type : frequency <</SYS>> How many people are affected by hypochondroplasia ? [/INST] The incidence of hypochondroplasia is unknown. Researchers believe that it may be about as common as achondroplasia, which occurs in 1 in 15,000 to 40,000 newborns. More than 200 people worldwide have been diagnosed with hypochondroplasia. </s>