Pompe Disease:
Pompe disease is an inherited disorder caused by mutation in GAA (acid alpha-glucosidase) gene. GAA gene is for production of an enzyme acid alpha glucosidase also known as acid maltase. This enzyme is active in lysosomes which act as recycling centres inside the cells. Mutation in GAA gene prevents acid maltase enzyme to break down glycogen effectively which allows this sugar to accumulate upto the toxic level which further damage tissues and organs throughout the body.
Sickle cell anaemia (SCD):
It is an autosomal recessive disorder of haemoglobin gene characterized by a sickle shape of RBC with hard and sticky structure. SCD occurs due to a point mutation which leads to conversion of seventh amino acid of Hb protein i.e. glutamic acid to valine.
Hemophilia:
It is an X linked recessive disorders mainly affecting males because of presence of single copy of X chromosome in males. It is a group of hereditary genetic disorder that impairs the blood clotting ability. Haemophilia A is caused due to factor VIII deficiency and haemophilia B is caused by factor IX deficiency. Haemophilia lowers blood plasma clotting factor levels needed for a normal clotting process. Thus when a blood vessel gets injured, a temporary scab does form, but the missing coagulation factors prevent fibrin formation, which is necessary to maintain the blood clot. A haemophiliac does not bleed more intensely but it bleeds for longer time than a normal person.
Purine and Pyrimidine metabolism related disorders
Disorders of purine salvage pathway:
Lesch-Nyhan syndrome:
This is a caused by deficiency of hypoxanthine-guanine phosphoribosyl transferase (HPRT) and a rare X-linked, recessive disorder. HPRT deficiency results in failure of the salvage pathway for hypoxanthine and guanine and these purines further degraded to uric acid. Additionally, a decrease in inositol monophosphate and guanosyl monophosphate leads to an increase in conversion of 5-phosphoribosyl-1-pyrophosphate (PRPP) to 5-phosphoribosylamine, which further enhances uric acid overproduction. Hyperuricemia predisposes leads to gout.
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