What is the type of inheritance that causes this disorder?

Bloom Syndrome
Bloom syndrome is a rare genetic disorder. It is characterized by short stature and a long narrow face with prominent nose and ears. There is also increased sensitivity to light. People who have the disorder often develop rashes on their face, forearms, and hands when they have been exposed to the sun. In addition, these people often suffer from chronic obstructive pulmonary disorder (COPD) and have a higher chance of developing cancer.bloom syndrome


The cause of this genetic disorder is a mutation in the BLM gene located on chromosome 15. The immediate effect of this mutation is that there is a defect in the functioning of the DNA helicase enzyme. The location of this gene on the chromosome is indicated by the yellow arrow.

Below is a pedigree showing the genealogy of the BLM mutation in one family. What is the type of inheritance that causes this disorder? Justify your answer with two points.