<s>[INST] <<SYS>> This is a medical question of type : frequency <</SYS>> How many people are affected by Glanzmann thrombasthenia ? [/INST] Glanzmann thrombasthenia is estimated to affect 1 in one million individuals worldwide, but may be more common in certain groups, including those of Romani ethnicity, particularly people within the French Manouche community. </s>