Mention any two autosomal genetic disorders with their symptoms.

(a) Sickle cell anaemia – When because of point mutation there is substitution of glutamic acid by valine in the sixth position of the beta globulin chain of haemoglobin, the biconcave shape of haemoglobin converts into sickle shape. This leads to decreased oxygen transport in blood, weakness

(b) Phenylketonuria – Person affected from phenylketonuria lacks an enzyme which converts amino acid and phenylalanine into tyrosine. Then this phenylalanine accumulates and converts into phenyl pyruvic acid and other derivatives. This disease causes mental retardation. Due to their poor absorption in kidney they are excreted in the urine.