Autosomal dominant inheritance

In this type of inheritance,One copy of a defective gene from either Mother or father causes disease in offspring or families.

In an autosomal dominant disease, if any offspring receives the abnormal gene from only one parent then offspring would be affected. On the other hand, Either father or mother may have the disease.

In an autosomal dominant disease, An abnormal gene is present  on the first to twenty second chromosome or Autosome or  nonsex chromosomes on father or mother and transferred to offspring as an autosomal disorder. A parent with an autosomal dominant condition has a fifty percent  chance to transmit this disease to their offspring but not all offspring. It means that each offspring  having disease does not depend on their sibling having the disease. If offspring do not receive  the abnormal gene. This disease  will not develop on this offspring. only twenty five percent of people are affected  from Marfan syndrome when his/ her parent does not have any gene of Marfan syndrome. 

Examples of autosomal dominant disorders 

Marfan syndrome is an autosomal dominant  disorder that affects connective tissue that support organs and other structures in your body. 

People with Marfan syndrome are usually tall and thin with unusually long arms, legs, fingers and toes. Marfan syndrome can be severe.   If aorta, a blood  vessel that  transports the  blood from the heart  body,  is affected. It may be fatal for life.

The signs and symptoms of Marfan syndrome are varied  among members of the same family. Some people have mild effects but in some cases these symptoms may be life-threatening. The symptoms of Marfan syndrome include Tall and slender  long arms, legs and fingers, A breastbone that becomes long abnormally, Abnormal  palate and crowded teeth, Extreme nearsightedness etc. Marfan syndrome affects the  gene that produces a protein responsible for the elasticity and strength of connective tissue.

Myotonic dystrophy is another autosomal dominant disease that affects the muscles systems. This disease usually recorded during adulthood between the age Twenty or thirty years. This disease is responsible for the  progressive muscle loss and weakness. People with myotonic dystrophy are not able to make muscle relax after the use.

Myotonic dystrophy is caused by mutations in the gene. The disease is inherited in an autosomal dominant manne. Myotonic dystrophy may be diagnosed when a hmedical expert observes signs and symptoms of the disease and  may be diagnosed  with tests of muscle function and genetic testing. The symptoms of this disease include muscle weakness, stiffness, tightness, and wasting. There are two types of myotonic dystrophy that are represented as type one  or type two. The symptoms  with myotonic dystrophy of type two are  mild  than type one. The symptoms of type one are appeared in legs, hands, neck, and face whereas symptoms of  the type two are seen in  neck, shoulders, elbows, and hips.

Some time the myotonic dystrophy may be congenital and present in child since birth. Symptoms of congenital myotonic dystrophy  include weakness of all muscles, breathing problems, reatard development etc.

Familial hypercholesterolemia

is a disorder  in which LDL or  bad cholesterol level is increased .The condition may appear since  birth and can cause heart attacks at an early age. It It is an autosomal dominant  genetic disorder. It is caused due to mutation on chromosome 19.

During this disorder, the body is not able to remove low density lipoprotein or bad  cholesterol from the blood. This results in a high level of LDL in the blood. As a result the arteries become narrower at an early age. The condition  is  passed through families in an autosomal dominant manner.

Next Article – Autosomal recessive disorder – Cystic fibrosis , Sickle cell anaemia , Tay Sachs disease


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