Early Intervention Services 0-4 yrs.

Pre School Readiness Skills 4-6 yrs.

School for Special Education 6-16 yrs.

Pre Voc & Vocational Centre 18+ yrs.

Recreational & Activity Club 5+ yrs.

Remedial Teaching Services Speech, OT,

Down Syndrome


What is Down Syndrome?

Down Syndrome is a genetic condition, affecting one in every 800-1000 births approximating 12,50,000 persons in India. It is not a disease. For centuries people with Down Syndrome have been mentioned in art, literature and ancient scripts. It wasn't until the late 19th century that John Langdon Down, an English physician, published an accurate description of a person with Down Syndrome. Dr. Langdon Down is recognized as the "Father" of the syndrome.

Throughout the 20th Century, advances in the field of medicine enabled researchers to investigate this syndrome in great detail. Finally in 1959, the French physician, Jerome Lejeune, identified Down Syndrome as a chromosomal anomaly.

The human body is made of cells, which contain a center, called a nucleus. The genetic material is stored in these cells and is known as Genes. These are responsible for our inherited characteristics. Genes are grouped in structures called chromosomes. The nucleus of each cell contains 23 pairs of 46 chromosomes, half of which are inherited from each parent. Thus, we get 23 chromosomes from our mother and 23 from our father. In Down Syndrome, the cells contain 47 chromosomes instead of normal 46 chromosomes. This occurs due to an error in cell division during gametogenesis, called non-disjunction. This means that one of the chromosome 21, from the pair does not separate, in either the mother or the father.

Non-disjunction : This happens either prior to or at conception. The chromosome 21, either in the ovum or sperm, fails to separate. This results in production of gametes with extra chromosome 21, which on fertilization with normal gamete produces an embryo with 3 copies of chromosome 21. As the embryo develops, the extra chromosome is replicated in every cell of the body. This is referred to as "Trisomy 21". This is responsible for 95% of all Down Syndrome cases.

TRANSLOCATION : is different type of chromosomal problem and occurs in only 3-4% of people with Down Syndrome. It occurs when a part of the pair 21 chromosome breaks off during cell division and attaches to another chromosome, which is either the chromosome pair 13, 14, 21 or 22. When this happens, the total number of chromosomes in the cell remains 46. The presence of an extra part of the number 21 chromosome causes the features of Down Syndrome.

MOSAICISM : About 1% of persons with Down Syndrome have mosaicism. When non-disjunction of the 21 chromosomes takes place after fertilization, in one of the initial cell divisions, it results in some cells with 46 and some with 47 chromosomes. Cells with 47 chromosomes contain an extra 21 chromosome. Because of this "mosaic" like pattern of the cells, the term mosaicism is used. Occurrence of this is quite rare.

Mosaic trisomy 21 is different from the simple trisomy 21 because in simple trisomy 21 all the cells have 47 chromosomes, whereas there are 2 or more than 2 cell population with normal 46 or trisomy 21 karyotypes or Robertsonian Transolocation.