Which of the following is not a hereditary disease -

The correct option is B Cretinism

-Haemophilia is an inherited bleeding disorder where the blood doesn't clot properly as the blood does not have enough clotting factors. It is C-linked recessive disorder related to a deficiency of antihaemophilic globulin protein.

-Cretinism is a condition characterised by physical deformity and learning difficulties that are caused by congenital thyroid deficiency. So it is a disease of the endocrine system which is non-inheritable.

-Cystic fibrosis is an autosomal recessive disorder in which fibrous cyst formation takes place in lungs and pancreas. The gene for the disease is present on Chromosome 7.

-Thalassemia is a quantitative disease. It is a hereditary hemolytic disease caused by faulty haemoglobin synthesis, widespread in African and Asian countries.

So, the correct answer is 'Cretinism'.