Other forms of HSS are probably also caused by a misspelling, but we now believe that they are misspellings in different genes. Classical HSS is an autosomal recessive genetic condition . This means that two copies of the misspelled HSS gene, one from each parent, are necessary in order for the disease to occur. Males and females are equally likely to be affected. In some families, the condition can be diagnosed early in pregnancy.
Every person is a carrier for about ten rare genetic conditions.
Parents of children with a rare genetic disorder are no different except that they happen to know one of their five or ten gene misspellings. But we have taken a big step by determining the approximate location of the classical HSS gene. We know that it sits near the end of the number 20 chromosome in all people. Now that we have an address for this gene, we can focus our hunt for the gene to just this small region. Once we find the classical HSS gene, we can begin to study the instruction that is unique to this gene.