BBSOAS is caused by changes (mutations) in or a deletion of the NR2F1 gene on chromosome 5q15.
If you think about our DNA as the letters of the alphabet, the mutation is typically a change of a single letter. This change causes a misspelling of the “words” made up by the alphabet. In this case, the information encoded by this gene is disrupted and non-readable. In other cases ‘the word’ is missing, due to a deletion.
Most affected people are the first person in their family to carry the gene change, but it can be inherited from a parent, who has features of BSSOAS as well. Each child of an affected individual has a 50% chance of being affected dependent on whether or not he or she inherits the mutated or normal copy of the gene from the affected parent. The condition affects boys and girls, and there are both mildly and more severely affected individuals of both sexes.