○ Thalassaemia is an inherited impairment of haemoglobin production in which there is a partial or complete failure to synthesise the specific type
of globin genes.
○ Thalassaemia is of two types Alpha and beta
○ In alpha thalassaemia there is the loss of one or more genes from chromosome 16 leading to production of less or no alpha chain
○ In beta thalassaemia there is no reduce beta chain production.
○ Beta thalassaemia occurs due to point mutation
○ Beta thalassaemia is commonly seen in Mediterranean area
○ Thalassaemia minor occurs in heterozygotes where in there is mild a little anaemia with no clinical disability
○ Thalassaemia minor is characterised by mild anaemia microcytic hypochromic Erythrocytes
○ Raised haemoglobin A2 Fraction.
○ Thalassaemia minor occurs in the offspring when it least one of the parent has
○ Thalassaemia major is a condition of beta thalassaemia where in the homozygotes are unable to synthesise haemoglobin
○ Mission is characterised by severe hypochromic anaemia red cell displasia, absence or grass reduction of the amount of haemoglobin A, increased level of haemoglobin F
○ Thalassaemia major occurs in the offsprings when both mother and father suffering from thalassaemia minor Alpha thalassaemia
○ Alpha thalassaemia is the condition where there is reduction or absence of alpha chain synthesis
○ Alpha thalassemia is common in South East Asia
○ Each chromosome contains two alpha gene loci and therefore total of four alpha genes are present in one pair of chromosomes
○ Deletion of two genes can lead to mild anaemia
○ Deletion of three genes can lead to haemoglobin H disease
○ Deletion of all the four genes leads to stillbirth known as hydrops Fetalis
○ Haemoglobin H is a beta chain tetramer formed from the excess of chains
Delta Thalassemia is less common andoccurs due to gene mutation for delta chain which comprises 3% of Hb.