Science has proven that this condition, which is identified as Down syndrome and intellectual disabilities, is due to presence of additional chromosome. There are 46 chromosomes in a human being compared to 47 in cases of humans identified with Down syndrome. This particular chromosome is found in the 21^st pair. Hence, this condition is also known as Trisomy 21. People with Down syndrome are differently abled and physically different in appearance compared to other human beings because of the presence of this additional chromosome. Their physical or mental development is delayed compared to regular human beings. Down syndrome also affects health conditions hence the people with this condition are more vulnerable to diseases. Parents have no role in giving birth to a child with Down syndrome. This fact has been established by various researchers and investigations. This condition is hereditary and chromosomes are formed at the time of formation of fetus of either parents or the lineage of both the families. Although considered hereditary, another reason for the chances of this condition is attributed to the mother’s age being more than 35 years. One among 700 -800 children is born with Down syndrome.

A fetus that has assumed the condition of Down syndrome remains protected in the mother’s womb so the child is born a regular child whereas in case of problems related to other chromosomes, the fetus gets destroyed and the child is lost way before the time of its birth.

Presence of various abnormal characteristics among humans, animal, birds, and plants can be called syndromes. Down syndrome is one among many such conditions found in humans.  A British doctor named John Langdon Down in 1866 BC first discovered Down syndrome, hence it got its name Down syndrome. Children with this condition were found to have Mongolian faces hence it was originally called Mongolian, however in the year 1961, on the request of the Mongolian community, the World Health Organization named it as Down syndrome by organizing a huge conference.

Gene plays a vital role in bringing about the condition of Down syndrome. Parental properties are transferred to the children via genes. Genes are present in innumerable numbers of cells in human body and they help us develop physically and mentally. Just as we need different software to operate different computational activities, the directions of genes operate our bodily activities. It is because of these genes that children bear resemblance to their parents in terms of physical stature and color of the skin. Genes are composed of a chemical called DNA and is present in humans in different quantities and states. Genes are always transferred in pairs. Genes get transferred from parents to children in pairs and cell comprises of chromosomes and chromosomes comprise of genes. As an example, 23 chromosomes from mother and 23 chromosomes from father get transferred to a normal child making 46 chromosomes in total 23 pairs. However in a child with a condition of Down syndrome there is a presence of 1 extra chromosome attached to the 21^st pair making the total number of chromosome 47. This evaluation is conducted by a test called Karyotype test.

There are three types of Down syndrome. The first type is Trisomy 21 and is found in children with a condition of Down syndrome. The likelihood of this type of syndrome is in 1 among 700 children. Parents expecting another child and who already have a child with the condition of Trisomy 21 stand a chance of 100 in 1 of giving birth to another child with the same condition. The second type of Down syndrome is called Translocation and is found in 3% to 4% of other children. The carrier in this syndrome is either of the parents and there is possibility of another child being born with the same condition from the same parents. The third type of syndrome is called Mosaic. In this condition, there are 46 chromosomes in some cells in the human body and 47 in some other. Very few children are born with this type of syndrome and they often appear to look like regular children.

Generally, children with the condition of Down syndrome can be identified by their physical make. However, it is important to conduct a chromosome test to be able to confirm it with certainty. The muscle make of children with the condition of Down syndrome is very weak which leads to doctors suspecting of children being in this condition. Due to weak muscle make and genetic condition there is a negative impact on children’s growth process which leads to delayed progress in the ability to walk, talk and even chew food. Doctors identify this condition as hypotonic. This condition cannot be treated; however certain degree of success can be achieved by the use of physiotherapy. Weights of children with Down syndrome have been found to be lesser than regular children when they are born. Physically, children with Down syndrome can be identified with their condition of weak muscles in their leg and hand joints, round faces, misaligned eyes, internal end of the yes covered with skin, small noses, poorly developed nose bridge , small mouth and a deep depression in the roof of their mouth. Children with this condition have thick tongues and they tend to stick their tongue out of their mouth and this condition have thick tongues and they tend to stick their tongue out of their mouth and suck on it. Their ear lobes and heads are found to be small and the rear side of their heads is comparatively broader. Children with this condition have irregularly grown teeth and in some cases there is absence of growth of teeth. Hands and arms are shorter, chests are protruded and stomachs are larger in size. The fingers in their feet are shorter and thicker and likewise, their necks are shorter and wider compared to that of regular children. This condition is characterized by dry skin that is prone to allergies. The space between their toes and immediate other fingers are found to be wider. Children with a condition of Down syndrome are usually shorter in height and their palms have a single distinct line. Either all or some of the above mentioned characteristics are found in people with the condition of Down syndrome.

It is not possible for a subsequent child to be born with this condition if the first child is born with this condition. However, it is advisable to consult a doctor for the fact that chances of another child being born with this condition are more in such couples. Normally people mistake this condition to be a disease, which actually is not. This condition occurs due to natural reasons. This condition cannot be treated with the help of medicine nor can be cured. Perhaps, this condition can be treated only through development of a technology that can isolate the chromosome that is attached with the 21^st chromosome but until such technological development it will be imperative for families, society and nations to concentrate on their education and upbringing to ensure that they become self-reliant and their rights as humans are safeguarded. Normally people with this condition are healthy and conditions of special ill health in them can be treated successfully.