Table 1: Effect of Mutations in Jak Family Genes in Humans and Mice

Deficiency in Mice Deficiency in Humans
TYK2 Impaired anti-viral, anti-fungal and anti-bacterial immunity, enhanced lung inflammation Autosomal recessive hyper-immunoglobulin E
JAK1 Perinatally lethal with major deficits in nerve development and lymphopoesis Deficiency not reported.
Acquired gain of function mutations associated with acute leukemia.
JAK2 Embryonically lethal due to defective erythropoesis Deficiency not reported.
Germline gain of function mutations associated with inherited polycythaemia, acquired mutations associated with myeloproliferative disease and acute leukemia.
JAK3 Severe combined immunodeficiency with lack of T, B and NK cells Severe combined immunodeficiency with lack of T and NK lymphocytes.
Acquired gain of function mutations associated with acute leukemia