What is Autosomal Dominant?

Autosomal Dominant can be described as one of the mediums through which a disease is passed on from one generation to another. Whenever the child gets one abnormal gene from either of the parent, then the disease is said to be autosomal dominant. In order to completely understand autosomal dominant, it is important to understand the meaning of the two words separately. Autosomal basically means that the abnormal gene is present in one of the chromosomes, while dominant means that one copy of the mutant gene is enough to cause the disorder.

Autosomal Dominant Disorder

For a person to get affected by an autosomal dominant disorder, only one copy of the abnormal gene is required. Inheriting a disorder or trait depends upon two main factors. One factor being the type of chromosome affected i.e. whether the chromosome is autosomal or whether it is a sex chromosome. Secondly, it depends whether the disorder is either dominant or recessive. There are twenty two nonsex chromosomes and a single abnormal gene on any of those chromosomes is enough to cause an autosomal disorder. In the case of Dominant inheritance, one abnormal gene from either of the parent can cause the disorder even if the matching gene in the other parent is normal. The abnormal gene always dominates the normal gene and in such as scenario, the child has more than 50% chance of having the disorder. Supposedly, if any couple has 6 children and there is an abnormal gene present in either the father or the mother, then three children out of six will have that abnormal gene present in them whereas the rest three won’t. Whenever an abnormal gene is found in any child, then it is suggest that the parents also undergo tests in order to detect the abnormal gene.

Dominant Genes

Dominant Genes are the genes that produce the same phenotype. A dominant gene is always full expressed in appearance. This can be explained with the help of an example Supposedly a person has one gene B=brown hair and another gene b=blonde hair, then the person will have brown colored hair as the gene B tends to dominate over the gene b. A dominant gene is always expressed and in this case the gene B will be fully expressed and the person will end up having brown color. The person will only have blonde color, when there are two recessive genes present.

Understanding Autosomal Recessive

Like Autosomal Dominant, Autosomal Recessive is another way through which a disease, trait or disorder is passed on from the parents to the child. However it differs from autosomal dominant as in this two copies of the abnormal gene must be present in order to develop the disease. In simple terms, the child will have to inherit the abnormal copy of the gene from both the father and the mother in order to express the particular disorder. Recessive basically means that one copy of the abnormal gene isn’t enough to cause the disorder and two copies of the mutant genes must be present.

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