For example, achondroplasia, a common form of dwarfism, usually occurs as a result of a mutation at base pair 1138 in a gene called FGFR3 on the short arm of human chromosome 4.

• 举例来说，软骨发育不全症（achondroplasia，一种常见的侏儒症）通常是人类第四对染色体短臂上FGFR3这个基因的第1138个碱基对发生突变。