HPS is a double autosomal recessive disorder. This means that a child has to inherit a faulty (mutated) gene from each parent) for them to have HPS. When an individual has a single faulty HPS gene they are known as an unaffected carrier because they do not have symptoms of HPS but may pass the faulty gene on to their children.
When two unaffected carriers have a baby:
The diagram below illustrates the various combinations of genes that children may inherit from parents who are carriers.
So far mutations on 9 different genes have been found to cause HPS in humans. In the laboratory ,mutations to 15 different genes have been found to cause HPS in lab mice. It is believed that more genes will be identified in humans over the coming years as high through-
The ‘true’ incidence of HPS is unknown but it is believed to occur across all nationalities and ethnic groups. Estimates for the UK and Europe vary between 1 in 500,000 to 1 in 1 million. The HPS Network believes that the ‘real’ incidence is higher because HPS is both under-
However HPS is extremely prevalent in Puerto Rico. In northwestern Puerto Rico one in 1,600 people in this region has HPS-